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El 19 de abril próximo será el 134 aniversario de la muerte de Darwin. Después de este casi siglo y medio, la evolución por selección natural sigue siendo objeto de muchas resistencias entre gran parte de la población del Estado más poderoso del mundo. La religión es la explicación fundamental de este hecho. Uno de los máximos especialistas en especiación, Gerry Coyne, escribió sin ñoñerías académicas que la selección natural es revolucionaria y es inquietante por el mismo motivo: explica el diseño aparente de la naturaleza mediante un proceso puramente materialista que no requiere de fuerzas naturales de creación o que guíen el proceso. Este es el principal motivo por el cual grupos religiosos cristianos se oponen a su enseñanza en las escuelas de EEUU

In order to understand the causes underlying the Triassic-Jurassic (T/J) mass extinction, we tested different bivalve features for extinction selectivity, i.e. shell mineralogy, age at the Rhaetian and three main autoecologic traits (feeding mechanism, tiering and motility/attachment). Also, diversity and turnover rates throughout the Triassic and the Early Jurassic were analysed in detail. The dataset employed for this analysis was a precise database at genus level including data from Induan to Sinemurian times. Results point to a true mass extinction for bivalves around the T/J boundary. This extinction was not ageselective at the boundary. Certain analyses suggested that shell mineralogy was a character significantly increasing survival odds, but this relationship seems to reflect selectivity on autoecologic traits. There was no difference in extinction proportions between both feeding types (i.e. deposit feeders and filter feeders); among the other traits, deep burrowers, epifaunal-motile and endobyssate forms seem to have been favoured, while shallow burrowers (and probably reclined forms) were more heavily affected. This pattern suggests an environmental stress at the boundary with some particular issues affecting the different life modes. Models linking magmatism in the Central Atlantic Magmatic Province with the end- Triassic mass extinction are a plausible scenario for this kind of perturbation.

The general aim of this dissertation is to investigate the evolution, the diversification and some ecological traits of the species of the strictly subterranean genus Troglocharinus Reitter, 1908. The genus Troglocharinus (Tribe Leptodirini, Family Leiodidae, Fig. 4) currently includes 19 species and 19 subspecies, and it is considered to be highly adapted to the subterranean environment (truly troglobiont, sensu Sket 2008), living exclusively in the deepest part of the cave in total darkness and very constant temperature and humidity (Salgado et al., 2008). Troglocharinus is distributed in two disjunct areas: some mountain systems south of the central area of the Pyrenees, and the coastal karstic formations between Tarragona and Barcelona, separated by extensive areas not suitable for subterranean species (sedimentary soils). Disjunct distributions like that of the genus Troglocharinus are very rare among the strictly subterranean genera, which tend to occupy a well-defined and restricted geographical region, usually within a continuous subterranean environment (Holsinger, 2005). The aim of this Thesis is to study the evolution and diversification of this genus, and establish a temporal framework for its range expansion. We also aim to test its thermal tolerance with an experimental and an evolutionary approach, to understand its possible role in the current distribution of the species and their biogeographic history. GENERAL DISCUSSION This thesis aimed to understand the biogeographic and phylogeographic mechanisms underlying the evolution and the diversification of obligate cave fauna, using as model a clade of strictly subterranean beetles. With this dissertation we contributed to challenge the traditional orthogenetic view on the origin and evolution of subterranean fauna, where hypogean organisms are classified as the senescence point of phyletic series prone to extinction. These ideas, strongly supported by Racovitza, Jeannel and Vandel during the XXth Centhury, still have a great impact on part of the biospeleological community (Romero 2009). Recent molecular work has demonstrated that the concept of “phyletic series” has not a phylogenetic mean, and that these series are often poliphyletic groups with still uncertain taxonomy. Subterranean beetles presents extreme morphological and physiological adaptations, and often their morphologies are very similar even among different groups, likely due to convergent adaptation. It is thus very difficult for morphologists to recognize phylogenetic relationships between species, and to assess their age and phylogenetic origin. Cryptic lineages can be recognized when applying molecular techniques, and our results support the need for a synergy between morphological and molecular data in the important effort to discover and preserve the fragile and threatened subterranean biodiversity. In this thesis the first data on thermal tolerance of strictly subterranean fauna is presented. The subterranean environment is a particular natural laboratory for testing evolutionary and ecological traits of their inhabitants, as it lacks many of the confounding factors present in epigean habitats. It is interesting that, when testing their thermal tolerance limits, and in contrast with the traditional assumption that species fine-tuned their thermal tolerance to the temperatures of their habitats, we found no differences in thermal tolerance between species belonging to clades subjected to different temperature regimes since the Pliocene, suggesting a lack of adjustment to ambient temperature in these organisms. Our results also indicate that models based only on actual conditions and distribution data are insufficient to make predictions on the fate of subterranean species in front of global change scenarios. In the last part of this dissertation we aimed to demonstrate the influence of the substratum on the dispersal capability and gene flow of cave obligate species, starting form the general principle that the habitat determined actual and historic demographic processes (Southwood 1977, 1988). This is one of the first comprehensive tests of the common view that geology of substratum represents the principal barrier to gene flow underground (e.g. Bellés 1973; Bellés & Martínez 1980)., El origen y la evolución de la fauna cavernícola ha sido tema de estudio y de debate desde los inicios de la biología evolutiva. La adaptación a un ambiente extremo como el subterráneo requiere cambios en múltiples aspectos (morfológico, fisiológico, ecológico...), y su estudio permite plantear cuestiones fundamentales sobre los procesos de adaptación y diversificación de los organismos. El objetivo general de esta tesis es investigar la evolución, la diversificación y algunos rasgos ecológicos de las especies del género estrictamente subterráneo Troglocharinus Reitter, 1908. El género Troglocharinus (Tribu Leptodirini, Familia Leiodidae) actualmente incluye 19 especies y 19 subespecies, y se considera altamente adaptado al medio subterráneo (truly troglobiont, sensu Sket 2008), o sea que vive exclusivamente en la parte más profunda de la cueva en la oscuridad total y con una temperatura y humedad muy constante (Salgado et al., 2008). Análisis previos mostraron que este género está anidado dentro de un ciado de origen Oligocenico que incluye otros géneros subterráneo de Leptodirini de los Pirineos (el grupo Speonomus, Ribera et al. 2010) El genero Troglocharinus se distribuye en dos áreas disjuntas: algunos sistemas montañosos al sur de la zona central de los Pirineos, y las formaciones kársticas costeras entre Tarragona y Barcelona, separadas por extensas áreas no colonizables por las especies subterráneas (suelos sedimentarios). Distribuciones disjuntas como la de género Troglocharinus son muy raras entre los géneros estrictamente subterráneos, que tienden a ocupar una región geográfica bien definida y restringida, dentro de un ambiente subterráneo continuo (Holsinger, 2005). El objetivo de esta tesis es el estudio de la evolución y diversificación de este género, y establecer un marco temporal para su expansión de rango. También tenemos como objetivo poner a prueba su tolerancia térmica con un aproche experimental y un enfoque evolutivo, para entender su posible papel en la distribución actual de la especie y su historia biogeográfica.

Xenacoelomorpha is, most probably, a monophyletic group that includes three clades: Acoela, Nemertodermatida and Xenoturbellida. The group still has contentious phylogenetic affinities; though most authors place it as the sister group of the remaining bilaterians, some would include it as a fourth phylum within the Deuterostomia. Over the past few years, our group, along with others, has undertaken a systematic study of the microscopic anatomy of these worms; our main aim is to understand the structure and development of the nervous system. This research plan has been aided by the use of molecular/developmental tools, the most important of which has been the sequencing of the complete genomes and transcriptomes of different members of the three clades. The data obtained has been used to analyse the evolutionary history of gene families and to study their expression patterns during development, in both space and time. A major focus of our research is the origin of ‘cephalized’ (centralized) nervous systems. How complex brains are assembled from simpler neuronal arrays has been a matter of intense debate for at least 100 years. We are now tackling this issue using Xenacoelomorpha models. These represent an ideal system for this work because the members of the three clades have nervous systems with different degrees of cephalization; from the relatively simple sub-epithelial net of Xenoturbella to the compact brain of acoels. How this process of ‘progressive’ cephalization is reflected in the genomes or transcriptomes of these three groups of animals is the subject of this paper.

We describe the organization of a nascent international effort, the Functional Annotation of Animal Genomes (FAANG) project, whose aim is to produce comprehensive maps of functional elements in the genomes of domesticated animal species

[eng] Mygalomorphs is a cosmopolitan group that inhabits all the continents except Antarctica. The group and has been commonly described as ‘primitive’ because of the retention of plesiomorphic characters, such as the presence of four book lungs and chelicerae bearing longitudinal fangs with unsynchronized movement. Those spiders have a cryptic lifestyle. They are nocturnal, ground-dwellers and construct buried silk burrows that are hidden by a closing a trapdoor. Females are mostly sedentary, long-lived, and they live in the burrow their whole life, whereas adult males have annual life cycles, and spread after the first mault searching for mates and mediate gene flow among populations. The low vagility, the long-life cycles, the narrow ecological preferences and the species restricted distribution makes mygalomorphs an excellent model system for biogeographic studies (Hedin et al. 2013; Raven 1980). This is due to the fact that ancient lineages with narrow habitat preferences and poor dispersal abilities are more likely to mirror the fingerprint of geological history (Stock, 1993; Bauzà-Ribot, 2013). Previous molecular studies indicate that they have extreme geographic structure. Low vagility has largely been cited as the main reason for the high level of local endemism in mygalomorph populations and species. Most of the closely related taxa are usually morphologically homogeneous and conserved (Bond & Hedin 2006). Diagnostic characters for species taxonomy are based on reproductive organs of adult males, but adults males spreads in a very concrete period of the year, that may vary depending on the environmental conditions, so the predominant sex obtained by direct capture are females o juveniles. This make extremely complicated the species identification because most of the taxonomic descriptions are old, inaccurate and based only on males, besides that females are unknown in most cases. There are six mygalomorph families present in the Western Mediterranean; the most diverse is the family Nemesidae , specially the genus Nemesia is extremely diverse with more than 50 species. In this thesis we investigated the origins and drivers of diversification of this genus. This study includes the first molecular phylogeny that confirmed that Nemesia and Iberesia are sister groups. Also we demonstrated high levels of sub-generic diversity, and the existence of putative species awaiting formal description . This sub-generic diversity is closely related with the degree of reduction of the spinnerets, that has been proved that contains phylogenetic signal and influences the architecture of the Burrows. The broke of the hercynian belt, and subsequentment rotation of the plates together with the isolation during Tortonian of the Betic-Rif area and the Messinian Salinity Crisis have been pointed out as major drivers of diversification in the region. At the same time we investigated the process that allowed those spiders to colonize Balearic Archipelago, the most isolated in the Mediterranean Region, our results showed that vicariance processes occurred during early Tortonian Marine Regression allowing the colonization from their origin in the Betic area. We applied integrative approaches to study patterns of high overlooked diversity in Tunisa, and 12 new species are described. We also try to decipher the mechanisms of coexistence of the genus. After two years of monitoring, our results show that coexistence is maintained by spatial and temporal segregation. Every specie has a maximum dispersal peak that doesn’t overlaps with other species, and furthermore those spiders have a strong habitat selection., [cat] Degut al seu críptic estil de vida i morfologia conservadora, els migalomorfs han plantejat importants reptes als taxònoms. El seu ús potencial com a organismes model no s'ha desenvolupat encara. Hem aplicat una aproximació integradora per investigar els orígens, mecanismes de diversificació i coexistència en aquest grup d'aranyes. Es proporciona la primera filogènia molecular del gènere Nemesia. Els nostres resultats recuperen monofilia recíproca dels gèneres Nemesia i Iberesia. Vam mapar la reducció de les fileres i hem demostrat que Holenemesia va evolucionar a partir d'un ancestre Pronemesia. L’ estudi mostra diferents graus de reducció en tots dos grups Curiosament, hem detectat una clara relació entre la reducció de les fileres i l'arquitectura del niu. Els espècimens d’Holonemesia construeixen caus complexes a diferència de Pronemesia, que construeixen nius senzills, no ramificats i amb poca seda. Aquest patró suggereix que la reducció en l'aparell de filat pot influir directament en el tipus de niu construït per l'espècie. Les nostres anàlisis donen suport a la Serralada Bètica com a origen de Nemesia. L’estimació de temps de divergència data els orígens de Nemesia al voltant de 40 mA (56-18 - 26.99 Ma). Les estimacions dels temps de divergència demostren que les diferents illes i també el nord d'Àfrica van ser colonitzades de la Península Ibèrica en diversos processos independents. La complexa història geològica i els canvis climàtics geològics soferts a la regió de la Mediterrània des de l'Oligocè fins al Quaternari van jugar un paper clau la generació de barreres a la dispersió o l'establiment de connexions terrestres entre les diferents masses de terra que permetien a la dispersió i colonització de diferents àrees. El gènere Iberesia té una distribució restringida a la Península Ibèrica, Illes Balears i el Marroc, on es va detectar la presència d'aquest gènere per primera vegada. Aquest gènere va ser descrit recentment per incloure les mostres sense fileres que s’havien considerat incorrectament Nemesia. En comparació a Nemesia, només tres espècies de Iberesia es descriuen en base a dades morfològiques.Els resultats d'aquest estudi mostren l'existència d'almenys 7 llinatges diferents i ben suportats, només dos d'ells van ser assignats a les espècies nominals (I. brauni i I. machadoi), mentre que I. Castillana no s’ha pogut trobar. Malgrat 9 espècies es coneixien del Nord d’Àfrica, no hi havia cap mena d’informació informació sobre la fauna de Tunísia. El mostreig va revelar alts nivells de diversitat en l'arquitectura del niu i trampa, mostrant estructures molt complexes. L’enfoc utilitzat combinant diferents línies d'evidències ha permès confirmar l'existència de 13 nous llinatges, 12 dels quals s’han descrit coma noves espècies. Es van detectar patrons de convivència entre espècies relacionades. Es va realitzar una anàlisi de la delimitació d'espècies mitjançant i durant dos anys es va dur a terme el seguiment de 5 localitats. Els nostres resultats mostren que la convivència és mantinguda degut a la separació temporal durant l'aparellament, cada espècie té el seu propi període de màxima dispersió però on el pic màxim de dispersió no es solapa i una marcada selecció de l’habitat.

[cat] Per entendre l’origen dels Opistoconts (grup taxonòmic que conté animals, fongs i diversos llinatges protists emparentats) o inferir les seves transicions evolutives, és fonamental primer entendre les relacions filogenètiques entre les espècies existents en l’actualitat. La filogènia, particularment la filogenòmica, és el procediment vàlid per inferir relacions evolutives entre espècies, ja que la morfologia, les sinapomorfies moleculars o els canvis genètics singulars són arguments cíclics dependents del mostreig taxonòmic. Per aquesta raó hem fet servir dades genòmiques i transcriptòmiques per a construir un nou conjunt de dades format per dominis proteics de còpia única i els hem analitzat mitjançat diversos mètodes per prevenir errors sistemàtics. Hem pogut així confirmar la divisió entre Holomycota (Nucleariids, Opisthosporidia, quitridiomiciets i fongs) i Holozoa (Ichthyosporea, Filasterea, Choanomonada i Metazoa). També hem obtingut dades de RNAseq per situar espècies particularment ambigües com: Corallochytrium limacisporum la qual hem situat com a grup germà de Ichthyosporea, un altre grup holozou osmotròfic. Partint d’aquesta base filogenètica es pot començar a especular sobre les transicions evolutives entre els grups. No obstant, abans cal reconstruir els ancestres dels llinatges dels Opistoconts com també dels seus grups externs actuals: Apusomonadida i Breviatea. Els resultats indiquen que no existeix cap lligam definit entre els bacterívors ancestrals biflagelats (grup extern) i cap dels llinatges Opistoconts (grup d’interès). També que el darrer avantpassat comú dels Opistoconts probablement conservaria quasi tots els caràcters ancestrals com el moviment ameboide, filopodis, la fagotrofia, etc.; però seria uniflagel·lat, amb una forma cel·lular menys restringida pel tipus d’alimentació. Mitjançant la genòmica comparada hem estudiat les similituds entre grups no emparentats d’Opistoconts com els osmòtrofs amb paret cel·lular o les amebes filopodials nues. Per exemple, hem trobat que Ministeria vibrans (Filasterea) i C. limacisporum (Ichthyosporea) presenten un aparell flagel·lar fins ara desconegut amb un patró similar al que formen fongs i altres eucariotes. També que Ichthyosporea fa servir un material semblant a la quitina per construir la seva paret cel·lular. Aquestes similituds plantegen hipòtesis de convergència evolutiva o paral·lelisme entre llinatges propers que s’hauran de comprovar en un futur., [eng] To understand the origin of opisthokonts or infer evolutionary transitions within the group that contains two multicellular lineages (animals and fungi), it is first fundamental to understand the phylogenetic relationships between extant living species. Phylogeny and particularly phylogenomics (such the supermatrix approach) is the only valid procedure to infer evolutionary relationships between species, as morphological or molecular synapomorphies or rare genomic changes are cyclic arguments and really taxon dependent. This is why we have used genomic and transcriptomic data to build a novel dataset of Single Copy Protein Domains and test phylogenetic hypotheses with multiple methods to discard problems of systematic error. We have confirmed the division between Holomycota (Nucleariids, Opisthosporidia, chytrid fungi and fungi) and Holozoa (Ichthyosporea, Filasterea, Choanomonada and Metazoa). We also have generated RNAseq data to place a specially elusive species: Corallochytrium limacisporum and found it placed as sister group to Ichthyosporea, another osmotrophic holozoan group. With this solid phylogenetic background we can start to speculate on evolutionary transitions between groups, but not before reconstructing ancestral character states in different opisthokont lineages and also the extant living outgroups: Apusomonadida and Breviatea. So we conclude that there is no clear link between biflagellated free-living gliding bacterivores (outgroup) and any opisthokont lineage (ingroup). The Last Opisthokont Common Ancestor was probably uniflagellated but retained all other ancestral characters such amoeboid movement, filopodia, phagotrophy, etc. but had a less constrained cell shape or feeding mode. Then, we studied the similarities found between non-related groups of opisthokonts, such the walled osmotrophs or the naked filose amoebae through comparative genomics. For example, we found that Ministeria vibrans (Filasterea) and C. limacisporum (Ichthyosporea) have a flagellar apparatus previously unnoticed, and with a molecular pattern of flagellum reduction also seen in fungi and other eukaryotes. Also, Ichthyosporea probably use a chitin-like substance to build their cell wall (similar to fungi) but with an independently diversified pathway.

[spa] Uno de los retos más importantes en biología evolutiva es entender las causas principales de la diversidad de fenotipos y de especies. La oportunidad ecológica (o el acceso a recursos nuevos y previamente inaccesibles) se considera como uno de los factores más importantes en la generación de nuevas especies y fenotipos. El objetivo principal de esta tesis es estudiar el papel generador de especies y fenotipos de uno de los grandes tipos de oportunidad ecológica, la colonización de islas. Para ello, se han usado dos sistemas continente-isla como modelo: los gecos de Arabia y el Archipiélago de Socotra y los gecos diplodactiloideos australasiáticos. Dado que las islas proporcionan ambientes con pocos competidores y depredadores, esto permite a los grupos insulares experimentar una gran expansión de nicho que puede estar asociada a una expansión del morfoespacio mediada por tasas elevadas de diversificación fenotípica y de especies. Los resultados de esta tesis respaldan totalmente esta hipótesis. Tanto en los gecos australasiáticos como en los gecos de Arabia y Socotra, la colonización de islas vino acompañada con aumentos sustanciales de disparidad fenotípica asociados con incrementos en las tasas de diversificación de tamaños del cuerpo y de especies. Aunque esto subraya la gran capacidad que tienen los entornos insulares en promover diversificación, diferentes grupos diversificando en las mismas islas no necesariamente siguen caminos evolutivos equivalentes. En el archipiélago de Socotra, la diversificación intra-isla en los géneros Hemidactylus y Haemodracon estuvo acompañada de grandes cambios del tamaño del cuerpo, que sólo posteriormente derivaron en cambios macroecológicos. Por el contrario, en el género Pristurus, la diversificación intra-isla fue principalmente mediada por cambios macroecológicos, siendo la diversificación del tamaño del cuerpo casi inapreciable. Esto demuestra que grupos cercanos diversificando en las mismas islas, pueden presentar patrones de diversificación completamente dispares. Al margen de las diversificaciones intra-isla expuestas, los resultados de esta tesis también han expuesto importantes patrones de diversificación también en el continente. Uno de ellos es el encontrado en los gecos pigopódidos australasiáticos, que después de adquirir una innovación clave (un fenotipo en forma de serpiente), entraron en dinámicas de diversificación comparables a los grupos insulares. Otro ejemplo destacado trabajado en esta tesis la diversidad encontrada dentro de la subespecie de geco Pristurus rupestris rupestris. Esta subespecie, en realidad, está formada por 14 especies altamente divergentes que diversificaron en las montañas del noroeste de Arábico, constituyendo uno de los casos más extremos de diversificación en vertebrados en Arabia., [eng] A major challenge in evolutionary biology is understanding the main drivers that underlie morphological and species diversity. Ecological opportunity—access to new or previously inaccessible niches—has been identified as one of the most important drivers of both phenotypic and species diversification. This is because the exploitation of new ecological niches is often accompanied by phenotypic differentiation among closely related taxa. This can in turn facilitate species diversification if phenotypic differentiation is associated with the appearance of reproductive isolation. The main goal of this thesis is to explore the extent in which a major source of ecological opportunity—the colonization of islands—have driven evolutionary diversification in different taxonomic and geographic contexts, specifically in the geckos of Arabia and the Socotra Archipelago and the Australasian diplodactyloid geckos. Island colonization is thought to provide a context of many available resources with few competitors and predators. This allows to colonizing groups the possibility to experience an “ecological release” and use a wider array of niches compared to their continental close-relatives. In such a situation, we expect an expansion of the morphospace in island groups typically associated with high rates of phenotypic and species diversification. We have found compelling evidence for this in both of the two mainland-island systems studied. The Australasian diplodactyloid geckos clearly expanded the range of phenotypic variation existing in the continent, producing the biggest and the smallest species in the radiation and were associated to accelerated rates of body size diversification compared to their closest relatives in the continent. Likewise, in the Hemidactylus geckos from Arabia-Socotra, island species were also associated to accelerated rates of phenotypic diversification and, as in the Australasian system, produced the most extreme sizes in the radiation. In this last mainland-island system, aside of reaching the maximum and the minimum sizes, the body size disparities in continental species assemblages were always significantly greater than the disparities computed by continental species assemblages. Nonetheless, when we compare Hemidactylus to other groups diversifying in the same islands, it appears that not all groups equally tend to diversify in body size. In fact, the comparison of the stages of diversification between the three gecko genera occurring in the Archipelago of Socotra revealed that not a single path of intra-island diversification was shared by all genera. Hemidactylus and Haemodracon greatly diversified in body size. However, in Pristurus diversification was strongly mediated by climatic shifts with size diversification being displaced to a subtle role. This is an important result as suggests that not all groups respond in the same way to similar amounts of ecological opportunity and that group-dependent (intrinsic) components can potentially play a role at defining the different stages of diversification. Aside of these examples of island diversification, in this thesis I also exposed remarkable examples of “island-like” patterns of diversification occurring in the continent. This was the case for the Australasian Pygopodidae, which attained rates of phenotypic diversification (possibly species diversification too) comparable to those found in island groups and was mostly mediated by the acquisition of a remarkable key innovation: a “snake-like” phenotype. Another remarkable example of continental diversification revealed in this thesis is a complex of highly divergent species existing within the subspecies Pristurus rupestris rupestris. This diversification took place in truly “island-like” setting, the Hajar Mountains in southeastern Arabia, formed by three main isolated blocks or “sky islands”. However, in this case diversification failed to take place within each of the “islands” and mostly was driven through intermittent pulses of dispersal and isolation taking place between two of the two main mountain blocks. Examples like this provide an example of how continental groups in some contexts, as the ones offered by mountain ranges, can fuel substantial amounts of diversification. In this case one of the greatest vertebrate diversification in Arabia.

[Background] A key question in evolutionary biology is the relationship between species traits and their habitats. Caves offer an ideal model to test the adjustment of species to their surrounding temperature, as they provide homogeneous and simple environments. We compared two species living under different thermal conditions within a lineage of Pyrenean beetles highly modified for the subterranean life since the Miocene. One, Troglocharinus fonti, is found in caves at 4-11°C in the ancestral Pyrenean range. The second, T. ferreri, inhabits the coastal area of Catalonia since the early Pliocene, and lives at 14-16°C., [Results] We found no differences in their short term upper thermal limit (ca. 50°C), similar to that of most organisms, or their lower thermal limit (ca. -2.5°C), higher than for most temperate insects and suggesting the absence of cryoprotectants. In longer term tests (7 days) survival between 6-20°C was almost 100% for both species plus two outgroups of the same lineage, but all four died between 23-25°C, without significant differences between them., [Conclusions] Our results suggest that species in this lineage have lost some of the thermoregulatory mechanisms common in temperate insects, as their inferred default tolerance range is larger than the thermal variation experienced through their whole evolutionary history., This work was partly funded by project CGL2010-15755 from the Spanish Government to IR.

[cat] Les zones àrides del Nord d'Àfrica i d'Aràbia s'estenen per diversos milions de kilòmetres quadrats i l'estudi en aquesta àrea dels patrons de biodiversitat a gran escala, es veu condicionat de forma essencial per la dificultat d'obtenir un mostreig complet, per l'escassa informació de la seva biota i per la complexitat dels processos que han generat la biodiversitat actualment existent. En el marc limitat d'una tesi doctoral, i considerant les premisses anteriorment descrites, s'han seleccionat dos gèneres de rèptils àmpliament distribuïts en aquestes àrees, el gènere Stenodactylus i el Ptyodactylus. Ambdós gèneres formen part dels elements més comuns de la fauna del Nord d'Àfrica i d'Aràbia, malgrat presentar importants diferències pel que fa a la seva morfologia, ecologia i patrons de divergència. Per un costat, les espècies dels dragons del gènere Stenodactylus són relativament divergents entre elles respecte a la morfologia, i han conquistat diferents ambients àrids i hiperàrids, incloent-hi alguns dels entorns més hostils dels deserts. Per altra banda, els dragons del gènere Ptyodactylus són més aviat conservats pel que fa a la morfologia, sempre presentant els característics coixinets triangulars dividits en múltiples làmines en les seves potes, i estan ben adaptats als substrats rocosos, que constitueixen el seu hàbitat estructural. Els resultats aquí presentats aporten un coneixement profund en les seves relacions filogenètiques, es revisa i s'actualitza la seva taxonomia, s'explora la seva biogeografia històrica, i en conjunt, es dona una imatge general dels patrons de diversitat dins d'un marc temporal pels ambients àrids del Nord d'Àfrica i d'Aràbia., [eng] The arid areas of North Africa and Arabia cover a surface of more than 13 million square kilometers and are characterized by their extreme temperatures, diversity of desert habitats and well-adapted flora and fauna. The study of the evolution of their biota sheds light on the diversification processes in some of the world’s harshest environments and contributes to our knowledge on large-scale biogeographic patterns and processes. The general aim of this dissertation is to investigate the evolution of the biota of the arid areas of North Africa and Arabia, through the study of the systematics and biogeography of two representative reptile groups, Stenodactylus and Ptyodactylus. The geckos of these two genera are among the most common faunal elements of the arid North African and Arabian environments, yet they are very distinct with regard to their morphology, ecology and patterns of species divergence. On the one hand, the naked toe Stenodactylus species are relatively divergent morphologically and have conquered different arid and hyper-arid habitats across plains or dunes. On the other hand, Ptyodactylus geckos are fairly conserved morphologically across their entire range and are very well adapted to a common type of structural habitat characterized by the rocky substrate. The results presented herein provide a thorough insight into their phylogenetic relationships, review and update their taxonomy, explore their historical biogeography and, altogether, assemble a broader image of diversity patterns within a temporal framework for the arid North Africa and Arabia. Highlighting the most relevant results, in this dissertation an unprecedentedly large set of samples from North Africa, the Sahel and Arabia was compiled for the two selected groups of study: 249 samples of Stenodactylus from 150 localities and 382 samples of Ptyodactylus from 221 localities. Regarding molecular data, 770 DNA sequences of five different markers were newly produced for the former genus, and 1443 of six different markers for the latter. Stenodactylus originated in Arabia in the Late Oligocene. The Arabian Clade B, including five species, and the mainly African Clade C, with the same number of species, split approximately 22 Ma ago, coinciding with the opening of the Red Sea. Diversification within several clades in the phylogeny occurred during the Late Miocene, a time when a general increase in aridification initiated. Based on mitochondrial and nuclear molecular data, as well as morphological characters, a new species of Stenodactylus is described. Stenodactylus sharqiyahensis sp. nov. is shown to be endemic to the sand desert of Al Sharqiyah, in northeastern Oman. Nomenclatural actions undertaken for the stability of the nomina of North African species of Stenodactylus include the designation of a lectotype for the nomen Stenodactylus guttatus which places it under the synonymy of P. hasselquistii, ensuring continuity of the prevailing usage of S. petrii, and the application to the International Commission of Zoological Nomenclature to accept a new name-bearing type for S. sthenodactylus, in order to maintain its prevailing usage. Regarding Ptyodactylus, its broad sampling includes numerous new records for some of the species, and especially for the P. hasselquistii species complex, an important extension of its known distribution range both in northeastern Africa and Arabia. All the formerly known and newly-delimited species are shown to be mostly allopatric, except some known cases where activity patterns are adjusted to avoid competition. This is hypothesized to relate to their preference for the same type of structural habitat, conditioning their apparently conserved morphology. The onset of the diversification in the genus Ptyodactylus is estimated to have taken place in the Late Oligocene. In the northeastern African and Arabian clades A, B and C, diversification started during the Late Miocene, approximately 9.5-12 Ma ago, posterior to that in the western African P. togoensis and P. oudrii. The molecular data show that many species have high levels of genetic variability. Ptyodactylus ragazzii presents two clades in the phylogeny, from East and West Africa respectively, and given that topological tests reject their sister relationship, the available name P. togoensis is assigned to the West African populations. Multilocus coalescence-based analyses with the use of GMYC and BPP methodologies result in the delimitation of 17 putative species in the P. hasselquistii species complex. These species are grouped in two major clades: Clade A, with nine species, is distributed across northeastern Africa and a large part of north, central and eastern Arabian Peninsula, and Clade B, with eight species, is restricted to southern Arabia.

La nostra evolució ha seleccionat una base biològica que marca uns limits al lliure albir per garantir la cohesió social.

L'altruisme és cabdal en l'evolució humana perque contribueix al fet que els nostres gens passin a la següent generació.

Engelken, Johannes et al., Extreme differences in allele frequency between West Africans and Eurasians were observed for a leucine-to-valine substitution (Leu372Val) in the human intestinal zinc uptake transporter, ZIP4, yet no further evidence was found for a selective sweep around the ZIP4 gene (SLC39A4). By interrogating allele frequencies in more than 100 diverse human populations and resequencing Neanderthal DNA, we confirmed the ancestral state of this locus and found a strong geographical gradient for the derived allele (Val372), with near fixation in West Africa. In extensive coalescent simulations, we show that the extreme differences in allele frequency, yet absence of a classical sweep signature, can be explained by the effect of a local recombination hotspot, together with directional selection favoring the Val372 allele in Sub-Saharan Africans. The possible functional effect of the Leu372Val substitution, together with two pathological mutations at the same codon (Leu372Pro and Leu372Arg) that cause acrodermatitis enteropathica (a disease phenotype characterized by extreme zinc deficiency), was investigated by transient overexpression of human ZIP4 protein in HeLa cells. Both acrodermatitis mutations cause absence of the ZIP4 transporter cell surface expression and nearly absent zinc uptake, while the Val372 variant displayed significantly reduced surface protein expression, reduced basal levels of intracellular zinc, and reduced zinc uptake in comparison with the Leu372 variant. We speculate that reduced zinc uptake by the ZIP4-derived Val372 isoform may act by starving certain pathogens of zinc, and hence may have been advantageous in Sub-Saharan Africa. Moreover, these functional results may indicate differences in zinc homeostasis among modern human populations with possible relevance for disease risk. © 2014 Engelken et al.

Les espècies d'aranyes del gènere Loxosceles són originàries de les zones temperades i tropicals d'Amèrica i d'Àfrica. La major part de les espècies tenen àrees de distribució relativament petites, tot i que existeixen algunes excepcions a aquest patró general, i algunes espècies amb hàbits antropòfils han estat transportades de forma passiva i introduïdes en diverses zones del planeta. Aquest és el cas, per exemple, de L. rufescens (Dufour 1820), l'única espècie descrita d'Europa. Actualment, la diversitat del gènere es concentra a Amèrica del Sud i del Nord, d'on s'han descrit la major part de les 107 espècies del gènere. L'objectiu principal d'aquesta tesi ha estat estudiar la diversitat del gènere Loxosceles a la Mediterrània, el Nord d'Àfrica i les Illes Canàries, i situar-la en un context filogenètic. L'intens mostreig de camp portat a terme per tota l'àrea d'estudi a posat al descobert l'existència d'una elevada diversitat. S'han identificat 11 llinatges mitocondrials dins de L. rufescens amb dos patrons filogeogràfics contrastats: (1) uns llinatges amb poblacions ben estructurades al Marroc i la Península Ibèrica, i (2) uns llinatges que manquen d'estructura geogràfica al llarg de la Mediterrània. Les estimes d'edats han situat la major part de diversificacions durant el Pleistocè, i la diferenciació al·lopàtrica dels llinatges és compatible amb els múltiples refugis Pleistocènics identificats amb la modelització de nínxol ecològics (ENM). Sembla que el transport indirecte pels humans ha complicat la biogeografia actual en aquesta espècie. En el cas de les Illes Canàries, les anàlisis filogenètiques han posat al descobert l'existència d'un clade ben recolzat endèmic de les Illes Canàries, format per set llinatges evolutius distribuïts de forma al·lopàtrica. La major part de dispersions entre Illes van succeir durant el Miocè superior. A més, també s'han trobat representants de l'espècie cosmopolita Loxosceles rufescens en l'arxipèlag. Sis dels llinatges pels quals es disposava de representants adults, s'han estudiat morfològicament i s'han descrit com a espècies nominals, quedant la diversitat de Loxosceles en les Illes Canàries amb una espècie endèmica de Fuerteventura i Lanzarote, dues de Gran Canària, dues més de Tenerife i una de La Gomera i El Hierro. Per tal d'aprofundir en la filogeografia de l'espècie endèmica de les illes i illots orientals, s'han desenvolupat set microsatèl·lits polimòrfics utilitzant les noves tecnologies de seqüenciació. Aquests nous marcadors han servit per a ressaltar la importància dels canvis en el nivell del mar i el vulcanisme en l'estructuració genètica d'aquesta espècie. Pel que fa a la diversitat de Loxosceles del Nord d'Àfrica, s'ha descrit una nova espècie de Loxosceles de Tunísia, L. mrazig, representant la segona espècie del gènere en la Conca Mediterrània. Tot i descriure's primerament d'una sola localitat, durant mostrejos posteriors s'han localitzat en diverses zones àrides del Nord d'Àfrica, des del Marroc fins a Israel. A més, l'estudi en profunditat a la regió del Souss-Massa del Marroc ha posat al descobert l'existència de diversos llinatges evolutius molt divergents molecularment i amb notables diferències morfològiques. L'estudi del verí de diferents llinatges de L. rufescens i de dues espècies de les Illes Canàries ha demostrat que existeixen diferències respecte a la composició principalment entre L. rufescens i les dues espècies canàries, que aquestes últimes expressen una diversitat menor de paràlegs de la família gènica SicTox, i que l'activitat esfingomielinasa D és en tots els llinatges i espècies estudiades tan elevada com en espècies americanes, les quals s'ha comprovat que poden provocar casos de loxoscelime., The spider genus Loxosceles Henieken and Lowe, 1832 is mainly distributed across the Americas and Africa. Most of the species show a narrow, circumscribed, distribution, although a few exceptions exist, for example L. rufescens (Dufour 1820), described from Europe. The aim of this thesis is to study the diversity of the genus Loxosceles in the Mediterranean Basin, North Africa and the Canary Islands, and to situate this diversity within a phylogenetic framework. The extensive sampling across the studied areas revealed the existence of hidden diversity. Using mitochondrial data, 11 different evolutionary lineages were identified within L. rufescens, presenting two contrasting phylogeographic patterns: (1) lineages with well-structured populations in Morocco and Iberia, and (2) lineages lacking geographic structure across the Mediterranean Basin. Dating analyses placed main diversification events in the Pleistocene, and multiple Pleistocene refugia, identified using ecological niche modelling (ENM), are compatible with allopatric differentiation of the lineages. Human-mediated transportation appears to have complicated the current biogeography of this medically important and synanthropic spider. This same species was found in the Canary Islands, where phylogenetic analyses revealed the existence of a well-supported clade formed exclusively by Canarian Loxosceles specimens, comprising seven allopatrically distributed evolutionary lineages. Morphological and molecular data confirmed the distinctiveness of six lineages and were described accordingly. Seven newly developed microsatellite markers were used to study the phylogeographic patterns of the species endemic to Fuerteventura and Lanzarote, and the study revealed the importance of sea-level changes and volcanism in shaping the genetic diversity in this species. Also, a new species of Loxosceles was described from Tunisia based on molecular and morphological data. Although this species was first described from a single locality, further sampling across North Africa expanded its distribution from Morocco to Israel. In the Souss-Massa region of Morocco, several highly divergent lineages were detected using molecular data and were shown to be also different morphologically. Using multiple approaches to study venom variation in selected species and lineages from the Mediterranean Basin and the Canary Islands, we found that SMase D activity, the key bioactive component of Loxosceles venom, is comparable to that of the American species that are confirmed to have medically relevant bites.

Venkatesh; Byrappa et al.-- This work is licensed under a Creative Commons Attribution- NonCommercial-Share Alike 3.0 Unported licence., The emergence of jawed vertebrates (gnathostomes) from jawless vertebrates was accompanied by major morphological and physiological innovations, such as hinged jaws, paired fins and immunoglobulin-based adaptive immunity. Gnathostomes subsequently diverged into two groups, the cartilaginous fishes and the bony vertebrates. Here we report the whole-genome analysis of a cartilaginous fish, the elephant shark (Callorhinchus milii). We find that the C. milii genome is the slowest evolving of all known vertebrates, including the 'living fossil' coelacanth, and features extensive synteny conservation with tetrapod genomes, making it a good model for comparative analyses of gnathostome genomes. Our functional studies suggest that the lack of genes encoding secreted calcium-binding phosphoproteins in cartilaginous fishes explains the absence of bone in their endoskeleton. Furthermore, the adaptive immune system of cartilaginous fishes is unusual: it lacks the canonical CD4 co-receptor and most transcription factors, cytokines and cytokine receptors related to the CD4 lineage, despite the presence of polymorphic major histocompatibility complex class II molecules. It thus presents a new model for understanding the origin of adaptive immunity. © 2014 Macmillan Publishers Limited.

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License. The images in this article are included in the article's Creative Commons license, unless indicated otherwise in the image credit; if the image is not included under the Creative Commons license, users will need to obtain permission from the license holder in order to reproduce the image., The distribution of mutational fitness effects (DMFE) is crucial to the evolutionary fate of quasispecies. In this article we analyze the effect of the DMFE on the dynamics of a large quasispecies by means of a phenotypic version of the classic Eigen's model that incorporates beneficial, neutral, deleterious, and lethal mutations. By parameterizing the model with available experimental data on the DMFE of Vesicular stomatitis virus (VSV) and Tobacco etch virus (TEV), we found that increasing mutation does not totally push the entire viral quasispecies towards deleterious or lethal regions of the phenotypic sequence space. The probability of finding regions in the parameter space of the general model that results in a quasispecies only composed by lethal phenotypes is extremely small at equilibrium and in transient times. The implications of our findings can be extended to other scenarios, such as lethal mutagenesis or genomically unstable cancer, where increased mutagenesis has been suggested as a potential therapy., This work was partially funded by the Botin Foundation (JS, RVS), by the Spanish Secretaria de Estado de Investigacion, Desarrollo e Innovacion grants MTM2010-16425 (CS, RM) and BFU2012-30805 (SFE), by grant 2009-SGR-67 from the Catalan government (CS, RM), by grant NSF PHY05-51164 (JS, SFE), and by the Santa Fe Institute (RVS, SFE).

[spa] El sistema quimiosensorial (SQ) participa en la detección de nutrientes, depredadores y pareja, siendo -por tanto- fundamental en la supervivencia de los organismos y de las especies. En insectos, las primeras etapas de la quimiopercepción están mediadas por familias multigénicas que codifican: (i) proteínas extracelulares, como las Odorant-Binding Proteins (OBPs) y las Chemosensory Proteins (CSPs); (ii) proteínas quimiorreceptoras, como los Odorant (ORs), Gustatory (GRs) e Ionotropic Receptors (IRs). Dado que la eficacia biológica de los individuos depende de su correcta expresión, estas familias multigénicas constituyen un excelente modelo para estudiar procesos adaptativos a nivel molecular. La creciente disponibilidad de datos moleculares nos ha conferido la oportunidad de comprender el papel de la selección natural en la evolución transcripcional de los genes del SQ. No obstante, la naturaleza masiva e innovadora de estos datos ha hecho indispensable el desarrollo e implementación de nuevos métodos de genética de poblaciones y evolución molecular en las potentes herramientas bioinformáticas DnaSPv5, BadiRate y popDrowser. Utilizando éstas y otras herramientas, hemos determinado que los genes que codifican OBPs no están distribuidos aleatoriamente en el genoma de Drosophila, sino agrupados formando clústeres de genes. La conservación de estos clústeres está relacionada con la amplitud y el ruido transcripcional de sus integrantes, así como también con su estado de la cromatina (’transcription elongation’ y con la unión de la proteína JIL-1). Entre otras funciones, la JIL-1 libera la ARN polimerasa pausada en la región promotora, lo que produce una ráfaga de elongación de la transcripción génica que incrementa el ruido transcripcional. Debido a que las fluctuaciones de OBPs pueden alterar el comportamiento de los individuos, este ruido transcripcional puede generar una plasticidad fenotípica beneficiosa, especialmente en ambientes externos cambiantes. La arquitectura de la región promotora puede jugar un papel fundamental en pausar la actividad de la ARN polimerasa. En este sentido, hemos inferido que las regiones upstream de los aIRs y las CSPs están sometidas a una importante constricción funcional, mientras que las de los ORs y los GRs han experimentado un mayor impacto de la selección darwiniana. Aunque aún faltan más evidencias al respecto, la evolución de las regiones upstream de las OBPs podría estar vinculada con el impacto diferencial de la cromatina en su regulación transcripcional. De cualquier modo, no cabe duda que la selección natural (negativa y positiva) ha contribuido significativamente a la evolución transcripcional de las principales familias multigénicas del SQ, mediante los mecanismos que implican elementos cis-reguladores y estados de la cromatina., [eng] The chemosensory system is involved in the detection of food, predators and mates, being thus essential for the species survival. In insects, the first steps of chemoperception are mediated by multigene families encoding: (i) extracellular proteins, such as Odorant-Binding Proteins (OBPs) and Chemosensory Proteins (CSPs), as well as (ii) chemoreceptors, such as Odorant (ORs), Gustatory (GRs) and Ionotropic Receptors (IRs). Since the fitness of individuals depends on their correct expression, these multigene families are an excellent model to study adaptive processes at the molecular level. The increasing availability of molecular data gives us the opportunity to understand the role of natural selection in the transcriptional regulation of the chemosensory genes. However, the massive and innovative nature of these data makes crucial the development and implementation of new methods for population genetics and molecular evolution in powerful bioinformatics tools, such as DnaSPv5, popDrowser and BadiRate. Using these and other tools, we determined that genes encoding OBPs are clustered along the Drosophila genome. The conservation of these clusters is related to the transcriptional amplitude and noise of their members, as well as to its chromatin state ('transcription elongation' and binding of JIL-1 protein). Among other functions, the JIL-1 releases the RNA polymerase paused at the promoter region, inducing a transcriptional elongation burst that increases expression noise. Because OBPs fluctuations can alter the behavior of individuals, this noise can generate a beneficial phenotypic plasticity, especially in changing external environments. The architecture of the promoter region can play a key role in the RNA polymerase pausing. In this regard, we have inferred that the upstream regions of aIRS and CSPs are under strong functional constraints, whereas Darwinian selection is more pervasive at the ORs and GRs upstream regions. Although further studies are needed, the evolution of the OBP upstream regions may be linked to the differential impact of the high-order chromatin regulatory mechanisms in the OBP transcription. Anyway, it is certain that natural selection (negative and positive) has significantly contributed to the transcriptional evolution of the major chemosensory multigene families, through mechanisms involving cis- regulatory elements and high-order chromatin states.

Recent events and those of past decades highlight the role of fear in public life. The fear and its causes are present in the mass media, political discourse, neuroscience, science and political philosophy. We take the view that intuitive, cognitive and heuristic fear management needs to be considered a basic feature of citizens’ lives in the current century. In both the modern vision of the nation and in the social contract, as well as in the most futuristic visions of cosmopolitanism and supranational states, the heuristic of fear will not disappear, not just because its intrinsic utility, but also its immanence at the genetic-biological and psycho-social level. We believe that the existence of fear is positive, as it alerts us to risks that may have a negative impact on the individual’s future., La actualidad y los acontecimientos de las últimas décadas han puesto de manifiesto la importancia del miedo en la vida pública. El miedo como tal y sus factores desencadenantes están presentes en la prensa, el discurso político, la neurociencia, la ciencia y la filosofía política. Entendemos que la gestión del miedo intuitivo, cognitivo y heurístico debe contemplarse como un elemento básico en la vida del ciudadano de este siglo. Tanto en la visión moderna de la nación y el contrato social, como en las visiones más futuristas de cosmopolitismo y estados supranacionales, la heurística del miedo difícilmente podrá desaparecer de los sistemas jurídicos y sociales, no solo por su utilidad intrínseca, sino también por su inmanencia y consubstancialidad genético-biológica y psico-social. El hecho de que exista miedo consideramos que es positivo puesto que nos alerta de riesgos que pueden afectar negativamente el futuro del individuo.

Heyn, Holger el al.-- This article, published in Genome Research, is available under a Creative Commons License (Attribution-NonCommercial 3.0 Unported)., DNA methylation patterns are important for establishing cell, tissue, and organism phenotypes, but little is known about their contribution to natural human variation. To determine their contribution to variability, we have generated genomescale DNA methylation profiles of three human populations (Caucasian-American, African-American, and Han Chinese-American) and examined the differentially methylated CpG sites. The distinctly methylated genes identified suggest an influence of DNA methylation on phenotype differences, such as susceptibility to certain diseases and pathogens, and response to drugs and environmental agents. DNA methylation differences can be partially traced back to genetic variation, suggesting that differentially methylated CpG sites serve as evolutionarily established mediators between the genetic code and phenotypic variability. Notably, one-third of the DNA methylation differences were not associated with any genetic variation, suggesting that variation in population-specific sites takes place at the genetic and epigenetic levels, highlighting the contribution of epigenetic modification to natural human variation. © 2013, Published by Cold Spring Harbor Laboratory Press., The research leading to these results received funding from the European Research Council (ERC) grant EPINORC under agreement number 268626, ERC Starting Grant (260372), NIH grants CA138461 and GM61388 (Pharmacogenomics Research Network), the MICINN Projects SAF2011-22803 and BFU2011-28549, the Cellex Foundation, the European Community's Seventh Framework Programme (FP7/2007-2013) from grant HEALTH-F5-2011-282510 (BLUEPRINT), and the Health and Science Departments of the Generalitat de Catalunya. I.H.H. is a fellow of the Generalitat de Catalunya (FI 2011).

[spa] Establecer las relaciones existentes entre las especies y definir los límites entre las mismas ha sido uno de los objetos principales de estudio de la biología evolutiva durante las últimas décadas. El establecimiento de estos límites se hace más complejo cuanto más cercanas son las especies entre sí debido a que comparten más características, tanto genéticas como morfológicas, lo que hace que en algunas ocasiones estos límites sean muy difusos, generando una mayor complejidad en la búsqueda de los criterios más precisos y menos sesgados para establecer los límites entre las especies. Bajo este marco conceptual, el objetivo principal de esta tesis doctoral ha sido la búsqueda, sirviéndose de herramientas morfológicas y filogenéticas, de los criterios que explican con un mayor grado de exactitud la relación existente entre dos especies cercanas de topillos, Microtus duodecimcostatus y Microtus lusitanicus, que se distribuyen a lo largo de la Península Ibérica. Estos dos topillos ibéricos pertenecen al orden Rodentia y, teniendo en cuenta que los roedores componen la mitad de las especies de los mamíferos y que además cuentan con un genoma con ciertas particularidades con respecto al del resto de los mamíferos, se desarrolló un conjunto de marcadores nucleares intrónicos específicos para los roedores. A partir de genomas de las bases de datos y mediante la aplicación de una serie de filtros bioinformáticos se seleccionaron 208 marcadores con unas determinadas características (tamaño, copia única, alta divergencia y evolución ajustada a la del resto del genoma) que permitieran usar estos intrones para resolver cuestiones filogenéticas a los niveles taxonómicos más bajos dentro del orden Rodentia. Una vez obtenido este conjunto de marcadores se escogió un subconjunto de ellos y se comprobó su validez mediante la amplificación y posterior uso para la reconstrucción filogenética en especies pertenecientes a varias familias representativas del orden Rodentia. Se obtuvo un elevado éxito de amplificación (78%) y las reconstrucciones filogenéticas de máxima verosimilitud y de inferencia Bayesiana con estos marcadores seleccionados reflejaron las filogenias propuestas para este orden en la literatura. Por otro lado, se empleó la técnica de la morfometría geométrica para determinar las características morfológicas principales que diferencian las dos especies de topillos, M. duodecimcostatus y M. lusitanicus, en las zonas de distribución alopátrica. Se identificaron cinco caracteres óseos que permitían una clara diferenciación morfológica entre las dos especies. Posteriormente se llevó a cabo, mediante estos caracteres, la asignación de especie a los individuos de las zonas de distribución solapada de las dos especies de topillos. A pesar de que en las zonas de distribución solapada se detectó una convergencia en forma entre las dos especies, se obtuvo una clasificación muy robusta de los individuos en una de las dos especies Por último, se llevó a cabo la caracterización de las dos especies de topillos ibéricos a nivel filogenético mediante el uso de un marcador mitocondrial, citocromo b, y de seis intrones de los desarrollados en la primera parte de la tesis. Se estimó, usando metodologías de reconstrucción de árboles de especies, que el tiempo de especiación entre estas dos especies es de 0,65 millones de años y que ambas especies sufren procesos de expansión poblacional, siendo este mayor en el caso de M. lusitanicus. A pesar de que estas dos especies se comportan como dos entidades separadas se detectó la existencia de una discordancia mitocondrial. Utilizando diferentes metodologías basadas en la teoría de la coalescencia se determinó que la causa más plausible de esta discordancia es un proceso antiguo de introgresión por hibridación de la especie M. duodecimcostatus hacia M. lusitanicus, originado así secuencias mitocondriales introgresadas en individuos de M. lusitanicus, siendo posiblemente los machos de M. lusitanicus los que invadieron las áreas de distribución de M. duodecimcostatus., [eng] Establishing the relationships among species and particularly defining the boundaries among them has been one of the main goals of Evolutionary Biology in recent decades. Assessing these limits becomes more complex when species are closely related, since they share more features, both genetic and morphological, and their boundaries are more diffuse. In such cases, it is crucial to identify accurate criteria to set the limits among species. In this scenario, the aim of this thesis has been to explore, using morphological and phylogenetic tools, wich are the criteria that explain with a higher degree of accuracy the relationship between two closely related species of voles, Microtus duodecimcostatus and Microtus lusitanicus (order Rodentia), that are distributed along the Iberian Peninsula, with a partial range overlap. In order to perform a multi-locus analysis of these species, a bioinformatic pipeline to extract intron sequences from already available rodent genomes was used, which allowed the identification of 208 introns. These introns were shown to be optimal to solve phylogenetic questions of closely related species in the Rodentia order. In addition, geometric morphometrics on skull bones and teeth was used to identify five characters to discriminate between the two species in their allopatric ranges. These characters also proved to be very powerful to discriminate species in the overlapped range, despite the existence of morphological convergence processes in this area in the two species. Finally, by multi-locus coalescence methods applied to the cytochrome b marker and a selection of six of the developed introns, a divergence time of 0.65 million years ago was estimated for these two species. Although these species behave as two separate entities, the existence of a mitochondrial discordance was detected. Using different methodologies based on the coalescent theory, it was determined that the most plausible cause of this discordance is due to an ancient process of introgression by hybridization from M. duodecimcostatus to M. lusitanicus.

[spa]El virus de la immunodeficiència humana 1 (VIH-1) conté una composició de nucleòtids diferent de la existent en el gens humans. Aquest fet planteja les qüestions de com la evolució ha triat la seqüència nucleotídica del VIH1 observada avui en dia, i de fins a quin punt aquesta seqüència actual contribueix a la capacitat replicativa, evolució i patogènesis virals. S’ha descrit que canvis en el ús de parelles de codons són eficaços per tal de generar virus atenuats de Poliovirus i Influenza. En aquesta tesi, hem aplicat la tecnologia prèviament descrita, “synthetic attenuated virus engineering” (SAVE) al VIH-1. Emprant parelles de codó sinònimes de manera racional, hem recodificat reoptimizant i desoptimizant per parelles de codó diferents fragments dels gens gag i pol del VIH-1. Les estructures de ARN i el us de codó dels nous fragments recodificats no es van veure afectades per la recodificació. Els virus desoptimizats van mostrar una replicació viral significativament inferior al virus control en cèl·lules MT-4 i en cèl·lules mononuclears de sang perifèrica (PBMCs). Depenent de la regió específica desoptimizada i del número de codons desoptimizats, es van obtenir diversos nivells d’atenuació ex vivo. Una reducció significant en la producció proteica es va observar quan la replicació viral va ser restringida a un sol cicle de replicació emprant un vector VIH-1 d’un sol cicle de replicació. La menor producció proteica no va correlacionar amb una reducció en el número de còpies del transcrit diana. Aquest fet suggereix que la transcripció, i no la traducció, es troba implicada en la generació dels fenotips atenuats produïts per la tecnologia de SAVE. El virus de proteasa reoptimizat que contenia 38 mutacions sinònimes, no es va mostrar atenuat, ans el contrari, mostrava una capacitat replicativa similar a la del virus control en cèl·lules MT-4 i en PBMCs. Encara que l’atenuació dels virus desoptimizats es basava en varies desenes de canvis nucleotídics, després de varis passis seriats en cèl·lules MT-4s, els virus desoptimizats de les regions de gag i proteasa van revertir a la virulència del virus control en cèl·lules MT-4. Alguns virus desoptimizats passats encara van mantenir un cert grau d’atenuació en PBMCs. Els anàlisis de quasiespècies de les seqüències dels virus passats en cultiu van mostrar que els virus atenuats acumulaven o bé mutacions sinònimes (reversions a la seqüència control o noves mutacions) o bé mutacions no-sinònimes. Els virus recodificats per la tecnologia de SAVE exploren diferents espais de seqüència. Singularment, no es va observar cap reversió important al virus reoptimizat passat en cultiu. Per tant, totes aquestes dades demostren que la tecnologia de SAVE és una estratègia útil per a afectar gradualment fenotípicament la capacitat replicativa del VIH-1, mitjançant un mecanisme que implica la traducció. El VIH-1 amb diferents nivells d’atenuació pot ser una eina utilitzable per al desenvolupament d’una vacuna segura i efectiva, així com pel desenvolupament de vectors lenvirals per a teràpia gènica més segurs, [eng]Human immunodeficiency virus type 1 (HIV-1) has a biased nucleotide composition different from human genes. This raises the question of how evolution has chosen the nucleotide sequence HIV-1 observed today, or to what extent the actual encoding contributes to virus replication capacity, evolvability and pathogenesis. Prior work has documented the effectiveness of making changes to the codon-pair bias of viral genomes in order to generate attenuated poliovirus and influenza virus. In this thesis, we applied the previously described synthetic attenuated virus engineering (SAVE) approach to HIV-1. Using synonymous codon pairs, we rationally recoded and codon pair–reoptimized and deoptimized different moieties of the HIV-1 gag and pol genes. RNA structures and codon usage of new recoded fragments were not affected by recoding. Deoptimized viruses had significantly lower viral replication capacity in MT-4 cells and peripheral blood mononuclear cells (PBMCs). Various degrees of ex vivo attenuation were obtained depending upon the specific deoptimized region and the number of deoptimized codons. After restricting viral replication to a single cycle by using a single-cycle HIV-1 vector, a significant reduction in protein production was observed in the vector carrying an attenuated virus variant. This reduction in protein synthesis was not accompanied by a reduction in the targeted transcript copy number, which strongly suggests that translation, and not transcription, is implicated in the generation of the attenuated phenotype by SAVE technology. A protease reoptimized virus carrying 38 synonymous mutations was not attenuated and displayed a replication capacity similar to that of the wild type virus in MT-4 cells and PBMCs. Although attenuation is based on several tens of nucleotide changes, after serial passages in MT-4 cells, both gag and protease deoptimized HIV-1 reverted to wild-type virulence in MT-4 cells while some maintain a certain attenuation degree in PBMCs. Quasispecies analysis of viral passaged sequences showed that attenuated viruses accumulated either synonymous mutations (reversions to wild-type sequences or novel mutations) or non-synonymous mutations. Recoded viruses explored different space sequences. Remarkably, no important reversion was observed in the reoptimized virus. Thus, these data demonstrate that SAVE is a useful strategy to gradually affect the replicative properties of HIV-1 by a mechanism that involves translation. HIV-1 with different degrees of attenuation can be a useful tool for the development of a safe and effective vaccine as well as the development of safer gene-therapy lentiviral vectors

[spa] El origen de la multicelularidad animal es una de las mayores transiciones evolutivas de la historia de la vida. La secuenciación, en los últimos años, de genomas de animales basales como esponjas y cnidarios ha permitido establecer la maquinaria genética común a todos los animales. La mayoría de estos genes son aquellos involucrados en la adhesión celular, la comunicación celular y el control de la proliferación y la diferenciación. El acceso a datos genómicos de organismos unicelulares muy cercanos a los animales, como Capsaspora owczarzaki, es esencial para entender mejor esta transición. Los objetivos principales de esta tesis ha sido estudiar la presencia de genes de multicelularidad y su conservación funcional en Capsaspora owczarzaki, así como su ciclo vital. Analizando su genoma, descubrimos una completa maquinaria de adhesión por integrinas en C.owczarzaki. Hemos podido reconstruir en detalle la historia evolutiva de este mecanismo crucial de adhesión y comunicación celular. También hemos encontrado un amplio repertorio de factores de transcripción, elementos esenciales para regular la diferenciación y la proliferación en los animales, que se creían exclusivos de animales en el genoma de C.owczarzaki; por ejemplo, genes NFkappaB, T-box o p53. Por último, hemos descrito que una importante vía de señalización en animales, la llamada vía Hippo, también está presente en C.owczarzaki. Este mecanismo es esencial para controlar la proliferación y el tamaño de los órganos en los animales. Mediante estudios de función heteróloga en Xenopus y Drosophila demostramos la conservación funcional de los homólogos del gen Brachyury (un factor de transcripción de la clase T-box) y de la vía Hippo de C.owczarzaki. C.owczarzaki y el coanoflagelado Salpingoeca rosetta nos sirvieron para estudiar la evolución y el origen de los filopodios y microvilli animales y su maquinaria molecular. Por último, el estudio de la biología y el ciclo de C.owczarzaki, mediante el uso de técnicas microscopias, citometría y transcriptómica comparada de los distintos estadios vitales del organismo. Demostramos la existencia de un estadio de pluricelularidad agregativa y que la transición entre éste y otros estadios está finamente regulada a nivel de expresión génica y de splicing alternativo. El estudio de C.owczarzaki nos ha dado valiosos ejemplos de cómo, más allá de la innovación génica, la co-opción de maquinaria pre-existente en un contexto unicelular fue un mecanismo esencial para el origen de la multicelularidad animal., [eng] The origin of animal multicellularity is a major evolutionary transition and a poorly understood one. In recent years, the sequencing of the genomes of several earlybranching metazoans, such as sponges and cnidarians, has allowed to define a common and exclusive molecular toolkit of animal multicellularity. Most of these genes are involved in cell adhesion, cell-cell communication and control of cell proliferation and differentiation, all of them essential functions for a multicellular organism. The access to genomic data of close unicellular relatives of animals, such as the choanoflagellates, has revolutionized the comparative genomic studies to understand the origin of animals and the molecular toolkit of the Urmetazoa (the common ancestor of all animals), showing that some genes that were considered exclusive to animals are, in fact, present in their unicellular relatives and were later co-opted to function in a multicellular context. The sequencing of the genome of the unicellular holozoan Capsaspora owczarzaki offers a new opportunity for further studying this topic. Thus, the main objectives of this thesis have been: first, to perform comparative genomic studies to reconstruct the evolutionary history of animal molecular toolkit; second, to study the functional conservation of some of the genes identified in Capsaspora owczarzaki by performing heterologous expression in model systems such as Xenopus laevis and Drosophila melanogaster; and finally, to study the life cycle and cell biology of Capsaspora owczarzaki to further understand the unicellular functional context in which this genetic toolkit of the multicellularity can act and may have evolved first. One of the main results of our comparative genomic studies is the presence of a complete integrin adhesome in Capsaspora owczarzaki and an almost full adhesome (including integrins) in the more distantly related Thecamonas trahens. This results allowed us to reconstruct the step-wise evolutionary assembly of this key machinery of animal multicellularity. Another important result is the finding of several transcription factors (essential tools for regulating cell differentiation and cell proliferation in animals) in Capsaspora owczarzaki previously considered exclusive to animals, for example NFkappaB, Myc/Max, Mef2, T-box, Runx,... Finally, we found in Capsaspora owczarzaki homologs of the components of the Hippo signalling pathway, an essential mechanism controlling cell proliferation and organ size in animals. Through heterologous expression studies we could study in detail the functional conservation of two of these machineries discovered in Capsaspora owczarzaki by comparative genomic studies. First, we studied the Capsaspora owczarzaki homolog of Brachyury (CoBra) using Xenopus laevis, the classical model system for studying Brachyury function. Brachyury is a T-box transcription factor involved in gastrulation and mesoderm specification in metazoans. We demonstrated that CoBra is functionally conserved and that it has similar DNA binding sites to those of animal T-box genes. Second, we used Drosophila melanogaster to demonstrate the functional conservation of three components of Capsaspora owczarzaki's Hippo pathway. One the most striking morphological features of Capsaspora owczarzaki is the presence of long filopodia. Using this organism and the choanoflagellate Salpingoeca rosetta we studied the origin and evolution of metazoan filopodia and microvilli and the associated molecular toolkit. We found that most components are innovations of animals and these two close unicellular lineages and that the microvilli originated in the common ancestor of animals and choanoflagellates. Finally, we studied the life cycle of Capsaspora owczarzaki using microscopy, flow cytometry and comparative transcriptomics of different life stages. We demonstrated the existence of an aggregative pluricellular stage in Capsaspora owczarzaki and that the transition between this and other stages is tightly regulated at the level of gene expression and alternative splicing. We also found evidence that the integrin adhesome is expressed in the aggregative stage, we an extracellular matrix is produced between the cells. The study of Capsaspora owczarzaki has provided valuable insights into the origin of animal multicellularity and emphasizes the fact that gene co-option was a major mechanism to generate to multicellular molecular toolkit of animals.

The mesoderm is the third germ layer, which is formed at gastrulation between the endoderm and the ectoderm in triploblastsc animals (Bilateria). The mesoderm differentiates into muscles, connective tissues and coelomic cavities. These structures have been key evolutionary innovations that prompted the enormous radiation of the bilaterians that at present make up for the 90% of animal species. As such, understanding the evolution of the mesoderm and its derivatives it is pivotal to understand the evolution of animals. In this thesis I have characterized the molecular patterning of the mesoderm and its derivatives (mainly muscles) in two different acoel species: Symsagittifera roscoffensis and Isodiametra pulchra. The acoels belong to the phylum Acoelomorpha (togheter with nemertodermatids and Xenoturbella). The phylogenetic placement of the Acoelomorpha is highly debated between a position basal to the bilaterians or nested inside the deuterostomes. The Acoelomorpha are morphologically simple animals and a trait sometimes considered a direct link to the cnidarians, the Bilateria sister group. With them they the acoelomorphs share a blind gut and a non centralized nervous system. Within the acoelomorphs, the acoels present the most derived body plan, however it is still rather simple if compared to other bilaterians. The nervous system for example is condensed anteriorly but not clear dorso ventral centralization exists as in most of the remaining bilaterians (the nerve cords are distributed circumferentially around the body). The mesoderm only develops from endodermal precursors, and this might be ancestral, since it is thought that the mesoderm evolved from the endoderm of a diploblastic, cnidarian-like ancestor. The muscles are the only mesodermal derivative in most basal acoelomorphs taxa, although in more advanced ones a parenchymal tissue, stem cells, and gonads also occupy the mesodermal space. The embryonic origins of the latter though, are at present still unknown. Thus acoelomorphs present most of traits considered to be eumetazoan ancestral traits (i.e. most of traits are also part of the cnidarians ground pattern), but still that the possibility that their body plan evolved in consequence of a secondary reduction must be considered as they could be more related to other deuterostomes than cnidarians. I have first investigated the molecular architecture of the muscles in the acoel Symsagittifera roscoffensis and found that although they have a smooth ultrastructural aspect they are molecularly more similar to the bilaterian striated muscles given that tey express key genes that control the contraction in the striated cells. This could be considered a first step into the evolution of the striated musculature without fully reaching it. Indeed, cnidarians have smooth epithelio muscular cells likely regulated by the same bilaterian smooth muscle proteins. However, the possibility of a secondary loss of the striation pattern cannot be discarded given that this already happened in some other bilaterians. Second, I have analyzed the expression of bilaterian mesodermal genes during embryogenesis and postembryonic development of Isodiametra pulchra and found that all but one (a FoxA ortholog) are expressed at the anterior pole, the site where the first myocytes start to differentiate. In juveniles and adults these genes are all expressed in muscles or at least a subset of them. Moreover the same genes are expressed in the gonads of I. pulchra and therefore it suggests that they could orginate in the endo-mesoderm of the worm. The cnidarians orthologues of these genes are expressed in the endoderm, which is moreover the site of the gametes differentation. The similarity between cnidarians endoderm and acoels mesoderm are astonishing, however before drawing conclusions we need a solid phylogenetic frame., Los acelos son unos gusanos, principalmente marinos, de simetría bilateral y aplastados según el eje dorso ventral, que pertenecen al grupo de los acelomorfos (acelos +nemertodermatidos+xenoturbellidos), cuya posición filogenética es tema de debate entre los biólogos evolucionistas. Los acelomorfos carecen de cavidades corporales, su sistema digestivo es ciego y su sistema nervioso consiste de una concentración neuronal anterior y cuerda nerviosas no claramente desplazadas hacía el lado dorsal o ventral. La simplicidad morfológica de los acelos, entremedia entre la de cnidarios y bilaterales superiores, les hace buenos candidatos para el estudio de la transición de animales radiales-diploblastos a bilaterales-triploblastos. En esta tesis se presentan datos sobre el desarrollo e la especificación molecular del mesodermo, que ha sido una de las innovaciones claves para la radiación de los bilaterales. S. roscoffensis que como todos los acelos tiene exclusivamente musculatura de tipo liso, expresa un gen ortólogo a la troponina, un proteína clave para la regulación de los músculos estriados, y que no existe en cnidarios. La explicación más parsimoniosa es que las bases moleculares de evolución de músculos estriados se han implantado en los acelos, aunque estos no hayan alcanzado la condición completa (explicación favorecida si los acelomorfos son confirmados como grupo hermano de los demás bilaterales). Por otra parte se puede considerar esta condición como debida a una reducción secundaria (explicación favorecida en el caso que los acelos se confirmen ser deuteróstomos). Los ortólogos de genes endodermales de cnidarios y con clara expresión mesodermal en bilaterales se expresan en la músculatura del acelo l. pulchra. Estos datos concuerdan perfectamente con la evolución del mesodermo a partir del endodermo de animales diploblásticos. Aun así, es difícil proponer un modelo específico de evolución de miocitos hasta que la posición filogenética de los acelomorfos no esté resuelta.

Letter to the Editor on Wang M, Wang Q, Wang Z, Zhang X, Pan Y. The molecular evolutionary patterns of the insulin/FOXO signaling pathway. Evol Bioinform. 2013;9:1–16. doi: 10.4137/EBO.S10539.

[spa] La asignación por sexo (SA) se refiere a la proporción de recursos asignados a la reproducción masculina y femenina. Un concepto relacionado es la razón de sexos (SR), el número relativo de machos y hembras. Su estudio científico trata de la variación en cantidad y calidad de cada sexo y de sus causas últimas y próximas. Las teorías adaptativas hacen predicciones bajo el supuesto de que el ajuste facultativo se ve favorecido cuando los beneficios en eficacia biológica compensan los costes. Empero, sus mecanismos son aún poco conocidos en vertebrados. En esta tesis se investigaron las causas de variación en la SA en aves, con especial énfasis en el papel del dimorfismo sexual en tamaño (SSD) y de otras características de estrategia vital. La primera sección presenta los resultados de un modelo de SR a nivel poblacional que incluye especies con distintos grados de SSD, en las que es posible estimar la fuerza de la selección para los ajustes. Los análisis comparativos mostraron que el SSD influye en los patrones de SR y vulnerabilidad diferencial de la descendencia. Otras características biológicas de las especies, sin embargo, parecen modificar estas relaciones. Una compleja matriz de factores parece actuar sobre el SR en aves, cuestionando la validez de las teorías de “inversión igualitaria" en este contexto. La segunda sección presenta estudios observacionales y experimentales de los factores que afectan a la asignación por sexo en el charrán común (Sterna hirundo). Se analizó el dimorfismo sexual en el fenotipo y estrategias de desarrollo de los pollos en relación a distintos factores. Los resultados subrayan (1) el potencial parental para influir en el desarrollo de la descendencia, a través del suministro diferencial de recursos, y (2) la influencia de la calidad parental en las diferencias sexuales, aunque pequeñas, de la descendencia. Además, se realizó un estudio del SR durante un largo período (7 años). Los patrones poblacionales de mortalidad y SR no revelaron desviaciones de la paridad, pero factores ambientales y de condición y calidad parental influyeron en el ajuste a nivel individual. Esta tesis pone de relieve las complejas relaciones entre la razón de sexos facultativa y los rasgos individuales y de estrategia vital que conducen a la evolución de la SA en aves., [eng] Sex allocation (SA) refers to the proportion of resources allocated to male and female reproduction; relatedly, sex ratio (SR) refers to the numbers of each sex that are produced. Hence, their scientific study deals with the variation in the quantity and quality of males and females and its ultimate and proximate causes. Adaptive theories make predictions about sex allocation under the assumption that facultative adjustment will be favoured when the fitness benefits compensate the fitness costs. However, although SA theory is one of the great successes of evolutionary biology and its mechanisms have been successfully applied to a number of taxa, they are still poorly understood in vertebrates. This thesis investigated causes of variation in avian sex allocation, with a focus on the role of sexual size dimorphism (SSD) and other features of avian life-history, associated with differences in the reproductive value of sons and daughters. In the first section, we present the results of tests of a sex ratio population model which involve species with sexual size dimorphism, in which it is possible to estimate the strength of selection for adjustments. Both species-level and phylogenetically controlled analyses showed that, across bird species, hatching and fledging sex ratios are influenced by the degree of SSD. Dimorphic species show a higher proportion of the smaller sex, but the effect is particularly strong in species with female-biased SSD. Parents adjust offspring sex ratio by differential production, possibly the less costly mechanism, rather than by sex-specific mortality. The degree of SSD is also correlated with offspring sex-biased vulnerability (expressed as a greater mortality and mass reduction of the larger sex). The survival and viability costs involved in achieving a larger body size support the size-dependent explanations of vulnerability. However, they should be combined with sex-dependent explanations, as growing large is mainly disadvantageous when coupled with the male-phenotype. Other life-history characteristics of the species, however, appear as potential modifiers of the relationship between SR and SSD. This reflects the composite matrix of factors that are acting on avian sex ratio evolution and questions the validity of “equal-investment” theories in this context. In the second section, the common tern Sterna hirundo was used as model species to investigate, via observational and experimental studies, the factors that could shape sex allocation in this slightly dimorphic species. In search for indications of different reproductive value/costs of each sex and possible differential parental allocation, we describe the sexual dimorphism in phenotype and developmental strategies of the offspring, related to environmental and parental traits. The results underline (1) the potential of parents to affect the development of their offspring by differential supply of particularly important resources, such as carotenoids; and (2) the influence of parental reproductive quality on the offspring sexual differences, even if these are slight. Furthermore, we performed a comprehensive study with complete information over a long period (7 years), to examine sex ratio and sex-specific mortality in common terns. Population patterns revealed no deviations from parity, but environmental factors and parental condition and quality affected sex ratio adjustment at individual level. Overall, this thesis highlights the intricate relationships between facultative sex ratios and individual and life-history traits which may drive the evolution of sex allocation in birds.

Background Pseudogenes are traditionally considered “dead” genes, therefore lacking biological functions. This view has however been challenged during the last decade. This is the case of the Protein phosphatase 1 regulatory subunit 2 (PPP1R2) or inhibitor-2 gene family, for which several incomplete copies exist scattered throughout the genome. Results In this study, the pseudogenization process of PPP1R2 was analyzed. Ten PPP1R2-related pseudogenes (PPP1R2P1-P10), highly similar to PPP1R2, were retrieved from the human genome assembly present in the databases. The phylogenetic analysis of mammalian PPP1R2 and related pseudogenes suggested that PPP1R2P7 and PPP1R2P9 retroposons appeared before the great mammalian radiation, while the remaining pseudogenes are primate-specific and retroposed at different times during Primate evolution. Although considered inactive, four of these pseudogenes seem to be transcribed and possibly possess biological functions. Given the role of PPP1R2 in sperm motility, the presence of these proteins was assessed in human sperm, and two PPP1R2-related proteins were detected, PPP1R2P3 and PPP1R2P9. Signatures of negative and positive selection were also detected in PPP1R2P9, further suggesting a role as a functional protein. Conclusions The results show that contrary to initial observations PPP1R2-related pseudogenes are not simple bystanders of the evolutionary process but may rather be at the origin of genes with novel functions.

Completely sequenced plastomes provide a valuable source of information about the duplication, loss, and transfer events of chloroplast genes and phylogenetic data for resolving relationships among major groups of plants. Moreover, they can also be useful for exploiting chloroplast genetic engineering technology. Ericales account for approximately six per cent of eudicot diversity with 11,545 species from which only three complete plastome sequences are currently available. With the aim of increasing the number of ericalean complete plastome sequences, and to open new perspectives in understanding Mediterranean plant adaptations, a genomic study on the basis of the complete chloroplast genome sequencing of Arbutus unedo and an updated phylogenomic analysis of Asteridae was implemented. The chloroplast genome of A. unedo shows extensive rearrangements but a medium size (150,897 nt) in comparison to most of angiosperms. A number of remarkable distinct features characterize the plastome of A. unedo: five-fold dismissing of the SSC region in relation to most angiosperms; complete loss or pseudogenization of a number of essential genes; duplication of the ndhH-D operon and its location within the two IRs; presence of large tandem repeats located near highly re-arranged regions and pseudogenes. All these features outline the primary evolutionary split between Ericaceae and other ericalean families. The newly sequenced plastome of A. unedo with the available asterid sequences allowed the resolution of some uncertainties in previous phylogenies of Asteridae.

El artículo intenta analizar la evolución histórica del creacionismo, describiendo las distintas fases que ha atravesado como relato o explicación sobre el origen del universo y la vida. Enfatiza la diferencia entre el discurso creacionista anterior a El origen de las especies y el posterior, al cual denomina ¿neocreacionismo¿ por su carácter antidarwinista o antievolucionista. También señala en su evolución dos transformaciones epistemológicas; la primera, de mero creacionismo a ciencia de la creación o creacionismo científico, y la segunda, de creacionismo científico a diseño inteligente. Con ello, completa un desarrollo histórico general en el cual el creacionismo, en su origen un mito cosmogónico-antropogénico, termina convirtiéndose en pseudociencia. Además, expone brevemente algunas de las implicaciones políticas, sociales e ideológicas de este proceso. This paper tries to analyse the historic evolution of creationism, describing its several stages that has gone through as a tale or explanation about the universe and life origins. Focuses the difference between creationism previous to On the Origin of Species and the subsequent one, which is named ¿neo-creationism¿ because of its antidarwinist or antievolutionist aim. It also points out two epistemological changes in its evolution: the first, from mere creationism to creation science or scientific creationism, and the second, from scientific creationism to intelligent design. As a result, the paper com-pletes a general historical development in which creationism, initially a cosmogonic and anthropogenic myth, ends to be a pseudoscience. In addition, exposes briefly some of the ideological, social and political implications of this process.

Animals have to eat a certain amount of food every day to survive. Since trophic resources are usually found in exposed locations, animals are in risk of predation while feeding, and face the well known trade-off between predation and starvation risks. Animals may reduce predation risk by scanning for predators. However, an increase in vigilance entails an increase in exposure time to predators. Therefore, animals may increase food intake to reduce foraging bouts at the cost of vigilance or may do the opposite. Animals may also reduce predation risk without increasing vigilance by joining groups. However, when food items are concentrated in some defendable patches, individuals will fight to access them, leading to interference competition. Birds have developed different vigilance and foraging strategies to cope with all these trade-offs. These strategies can be adapted to the environmental conditions and type of predators, and will highly differ according to the genetic, phenotypic and ecological characters of the individuals. In this thesis I investigated how wintering Eurasian siskins (Carduelis spinus) adjusted their vigilance and foraging behaviour to predation risk and competition, and how this adjustment varied according to conspicuousness, residence status and personality of focal birds. I also studied how resident and transient siskins regulated their body mass to predation risk. In order to determine the differential effects of predation risk and competition on the behaviour of siskins, I designed an experiment with three feeders differing in predation risk and interference competition. I captured the siskins every week and marked them with aluminium rings (at first capture) and colour rings (if residents). From each bird, I measured body mass, wing length and plumage coloration cues. I filmed the siskins foraging at feeders from a hide. Then I analyzed the video recordings and selected a sample of birds at each feeder to study the effect of environmental factors, and selected pairs of birds belonging to different cohorts of sex, residence and personality to compare their vigilance and foraging behaviour. I also compared body mass of a large sample of residents and transients in two periods with and without avian predators. I found that siskins adjusted their vigilance behaviour specifically to the environmental conditions. Vigilance to predators, achieved by reducing inter-scan durations, was less costly in terms of food intake rate than vigilance to flockmates, achieved by increasing scan durations. Siskin males were more brightly coloured and detectable than females, and showed a vigilance system more oriented to predator detection, supporting (together with the correlation between coloration and vigilance in males) the view of a predation cost to conspicuousness. Resident and transient siskins showed a different vigilance and foraging strategy. Residents were more confident in vigilance to reduce predation risk while transients preferred to reduce foraging bout lengths. Transient siskins were in higher predation risk because of their vigilance and foraging behaviour, and this was related both to their unfamiliarity with the area and their subordination to residents. Proactive male siskins showed a vigilance system that improved their ability to detect predators as compared with reactive males, supporting the view of a behavioural compensation for their personality trait (and not the existence of behavioural carryovers). Resident siskin males adjusted their body mass to the presence of predators at the foraging area, something that transients could not do because of their site unfamiliarity. In general, dominant individuals (whether males, residents or proactive birds) showed a foraging behaviour that prioritized the reduction in predation risk and not the increase in food intake rate, as compared to subordinates. Dominance alone cannot account for our results, although it probably had some effect in all the comparisons., En aquesta tesi vaig estudiar el comportament de vigilància i d'alimentació de lluers hivernants a tres menjadores que diferien en risc de depredació i competència. Vaig determinar com els ocells ajustaven la vigilància a aquestes variables, i vaig comparar el comportament dels ocells pertanyents a diferents classes de sexe, estatus de residència i personalitat, per veure si adoptaven diferents estratègies. Els lluers van ajustar de manera diferent el seu comportament al risc de depredació i la competència. La vigilància dirigida als depredadors, assolida tot reduint la durada dels intervals entre vigilàncies, va resultar ser menys costosa en termes d'ingesta d'aliment que la vigilància a companys d'estol, assolida mitjançant l'increment de la durada de les vigilàncies. Els mascles de lluer van ser més brillants i fàcils de detectar que les femelles, i van mostrar un comportament més orientat a la detecció de depredadors, cosa que dóna suport (junt amb la correlació entre coloració i vigilància en mascles) a l'existència d'un cost de depredació associat a la conspicuïtat del plomatge. Els lluers residents van adoptar un sistema de vigilància que els exposava a menor risc de depredació que els transeünts. A més, a diferència d'aquests, van confiar sobretot en la vigilància a l'hora de reduir el risc de depredació. Aquestes diferències estarien relacionades tant amb el grau de coneixement de la zona com amb la dominància. Els mascles proactius van mostrar un sistema de vigilància que millorava la seva capacitat per detectar aviat els depredadors en comparació amb els mascles reactius, cosa que dóna suport a la idea d'una compensació comportamental del tret de personalitat. Els mascles residents van ajustar la seva massa corporal a la presència d'un depredador aeri a la zona, cosa que no van fer els transeünts segurament pel seu desconeixement del risc de depredació. En general, els individus dominants (mascles, residents o individus proactius) van mostrar un comportament d'alimentació que prioritzava la reducció del risc de depredació i no l'increment en la ingesta d'aliment. La dominància per sí sola no pot explicar els resultats de les comparacions, malgrat que pot tenir un cert efecte en totes elles.

[spa] El uso de señales múltiples de calidad es común en numerosas especies, pero este hecho no es fácil de explicar. Las presiones fluctuantes del ambiente podrían tener un rol importante en el origen y mantenimiento de las señales múltiples, y las implicaciones evolutivas de esta hipótesis enfatizan la importancia de realizar nuevos estudios sobre señales múltiples. En esta tesis se realizaron diferentes estudios sobre la señalización múltiple del plumaje de dos especies de aves: El carbonero común (Parus major) y el lúgano (Carduelis spinus). En el primer capítulo se examinó la banda alar amarilla del lúgano, un ornamento sexual basado en carotenoides. Se vio que machos con bandas alares mayores eran más rápidos resolviendo un problema de forrajeo. Esto sugiere la existencia de una selección sexual de habilidades cognitivas en el lúgano. En el segundo capítulo, estudiamos la función del babero negro del lúgano como señal de la personalidad del individuo. Descubrimos que lúganos con baberos de mayor tamaño mostraban tendencias exploratorias más rápidas. Este hallazgo apoya la idea de que los ornamentos del plumaje pueden funcionar como señales de la personalidad del individuo. En el tercer capítulo se examinó cómo las señales múltiples pueden definir el comportamiento sexual extra pareja. Se pudo constatar que la respuesta agonística y la paternidad de machos de carbonero dependía de la interacción entre la corbata negra y la coloración amarilla del pecho del macho, sugiriendo la existencia de diferentes estrategias reproductivas de acuerdo a la calidad individual. Por último, examinamos las posibles interacciones entre ornamentos sexuales y la familiaridad, mediante experimentos de selección de pareja en lúganos. Nuestros resultados sugieren que la familiaridad puede ser tan importante como los ornamentos sexuales a la hora de determinar los criterios de selección de la hembra. En conclusión, esta tesis profundiza en el hecho de que las diferentes cualidades de un individuo, reflejadas en distintas señales múltiples, tienen el potencial de ser parte de diferentes estrategias válidas en selección sexual y social, permitiendo una selección más plástica. Esta plasticidad de selección podría ser uno de los mecanismos tras el origen y mantenimiento de las señales múltiples., [eng] In sexual or social selection processes, animals employ traits that signal qualities. The use of multiple signals is known to be well spread in numerous species, but the ultimate reasons for using more than one single signal are not easy to explain. Why would animals invest in several different signals, instead of focusing on only one? Traditionally, the adaptive hypotheses formulated to explain the existence of multiple signalling have been framed into static scenarios, under constant selection pressures. However, there is increasing awareness of the need to widen this static framework, by taking into account the selection plasticity produced by spatial and temporal environmental heterogeneity. Fluctuating ecological and social environments could have an important role in the origin and maintenance of multiple signals. In an environment where changes happen faster every day, multiple signalling would allow a more flexible, dynamic selection, increasing the odds of survival and fitness. The evolutionary implications of this hypothesis highlight the importance of novel studies in multiple signalling. In this thesis, we performed several such experiments on the Eurasian siskin (Carduelis spinus) and the Great tit (Parus major). They are two passerine species that show ornaments based on melanins and carotenoids, which makes them a particularly suitable models for the study of multiple signalling. In the first chapter, the signalling function of the yellow wing stripe of the Eurasian siskin, a carotenoid based sexual ornament, was examined. A problem solving experiment showed that male siskins with longer yellow wing stripes were better foragers. These resuls suggest the existence of sexual selection for cognitive abilities. In the second chapter, we studied the function of the black bib of the Eurasian siskin as a potential source of information about the personality of the individual. We examined the exploratory behaviour of male siskins, finding that those with larger black bibs had a shorter approaching latency to a novel object. These results support the idea that plumage structures could give information about the personality of its bearer. The results of these two chapters show that colour signals based on different pigments have separate functions in the siskin, allowing multiple criteria in sexual (and social) selection. The third chapter examined the effects of different multiple colour signals on the extra pair sexual behaviour of the great tit. By measuring the response of different males to conspecific male intrusions, and the within pair paternity of males depending on their colour traits, we could observe that different combinations of traits where related to the intensity of nest defence, and implied differences in paternity loss. These findings suggest that males might be using different strategies to maximize their qualities. In the last chapter, we tested the potential interactions between colour sexual ornaments and the previous experience, by sexual selection experiments in siskins. Our results suggest that familiarity adds to attractiveness when female siskins choose a mate. At least in some species, females are using multiple criteria in mate choice, not necessarily related to external signals of quality. In conclusion, this thesis stress that multiple qualities, signalled by different colour traits, have the potential to be part of different successful social and sexual mate choice strategies, aiding a more plastic selection. Our results support the hypothesis that selection plasticity could be one of the mechanisms behind the origin and maintenance of multiple signals

Diversity dynamics among bivalves during the Triassic and Early Jurassic provides the opportunity to analyse the recovery patterns after two mass extinctions: Permian/Triassic and Triassic/Jurassic (T/J). The results presented here are based on a newly compiled worldwide genus-level database and are contrasted to the main morphological characters of the different taxonomical (orders and their constituent families and genera) and ecological groups. Many of such morphological characters are innovations appearing during the time span considered. Diversity and evolutionary rates were assessed and compared between these groups. During the Early Triassic there was a slow recovery, dominated by epifaunal taxa, the order Pectinida being the most diverse. The major post-Permian radiation took place during the Anisian, with several morphological and ecological innovations appearing and/or diversifying. The Late Triassic was a time of great diversification and ecological specialisation. Although the T/J was a true mass extinction for bivalves, it was not indiscriminate as its impact was stronger on specialised orders and not all ecological categories were equally affected. Recovery during earliest Jurassic was fast, confirming the high-evolutionary resilience of bivalve molluscs, except for groups with thick shells and tropical distribution, probably because of a biocalcification crisis. Fil: Ros, Sonia. Universidad de Valencia; España. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Paleozoología Invertebrados; Argentina Fil: Echevarría, Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Paleozoología Invertebrados; Argentina

Per solucionar el sobrepés cal lluitar amb un model d'alimentació que és resultat de milions d'anys d'evolució instintiva i metabòlica

Gracias a la evolución biológica y cultural el ser humano ha sido capaz de adaptarse al ambiente. Una opción para mejorar las prestaciones humanas podría ser la obtención de un cyborg o ser humano biónico en el cual la parte inorgánica fuese un chip computacional conectado directamente al cerebro. Esta y otras posibilidades se debaten en el presente artículo., The human being has been able to adapt to the environment due to the biological and cultural evolution. One option to improve the human characteristics could be to obtain a cyborg or a bionic human being with a computational chip directly connected to the brain. This and other possibilities are discussed in the present paper.

L'Univers cultural humà és extremamwnt complex i inclou des de creences dogmàtiques fins a explicacions científiques, que coexisteixen en la societat i fins i tot en la ment de l'individu.

Anàlisi exhaustiu del mètode EM aplicat a la reconstrucció filogenètica. Aplicació del mètode per a la reconstrucció de topologies sobre dades simulades sota un model K3. Aplicació i comparació amb altres mètodes de reconstrucció filogenètica coneguts, com l'algorisme Neighbor-Joining, un mètode basat en invariants i un algorisme de màxima versemblança que es troba en el programari PAML. S'han trobat els estimadors de màxima versemblança en l'algorisme EM sota un model K3 i un GMM i s'ha pogut veure l'eficiència de l'algorisme EM respecte el altres, tot i que amb un temps computacional molt més elevat. I la millora en la reconstrucció de topologia a mesura que les longituds dels alineaments eren majors.. La reconstrucció de l'arbre filogenètic que ha donat lloc a les espècies actuals no és una tasca fàcil i en aquests moments encara s'estan proposant nous mètodes de reconstrucció. Entendre els models matemàtics d'evolució més usats és una de les claus per a proposar nous mètodes de reconstrucció. En aquest projecte programarem un mètode de màxim de versemblança per a models evolutius a temps discret i el compararem amb altres mètodes de reconstrucció ja existents i amb noves adaptacions d'aquests.

[cat] Els gens estan sotmesos a forces selectives diferents. Un dels objectius de la Biologia Evolutiva és entendre els factors que determinen aquestes diferències. Els gens rarament actuen de manera aïllada, sinó que normalment funcionen com a elements de xarxes complexes formades per un gran nombre de molècules que interactuen entre si. Tot i la rellevància d’aquestes xarxes per entendre l’evolució dels gens, les propietats evolutives d’aquestes xarxes són encara poc conegudes. En aquesta tesi hem estudiat les forces selectives (selecció positiva i negativa) que han actuat sobre els gens implicats en la via de la insulina/TOR, i hem relacionat aquestes forces amb la posició dels gens a la via. Aquest estudi s’ha realitzat en 12 espècies del gènere Drosophila (primer article de la tesi), i en 6 espècies de vertebrats (humà, ratolí, vaca, opòssum, ornitorinc i pollastre) (segon article). A aquests efectes, s’han identificat i anotat els gens implicats a la via en totes les espècies estudiades, s’ha reconstruït la seva història evolutiva mitjançant tècniques d’anàlisi filogenètica, i s’han caracteritzat les forces evolutives que hi han actuat a partir de la relació la divergència no sinònima (dN) i sinònima (dS), ω = dN/dS. Totes les famílies gèniques estudiades tenen almenys un representant a totes les espècies estudiades. A més, tots els gens estudiats estan sotmesos a selecció purificadora, la qual cosa indica que aquests gens són funcionals. Per tant, tots els organismes estudiats presenten una via de la insulina/TOR completa i funcional. Tant a Drosophila com a vertebrats, observem que el nivell de limitació funcional (o selecció purificadora) sota el que evolucionen els gens es correlaciona amb la posició dels gens a la via (mesurada com el nombre de passos des del receptor de la insulina –posició 0– fins la resta de components –posicions 1 a 10), essent els gens de la part downstream els que evolucionen sota un major grau de limitació funcional. El sentit d’aquesta correlació és contrari al que s’ha trobat generalment en rutes metabòliques, on són els gens de la part upstream es que estan sotmesos a un major grau de limitació funcional. Vam avaluar l’impacte d’una sèrie de factors que es correlacionen amb ω (selecció positiva, nivell d’expressió gènica, nombre de teixits en què un gen s’expressa, grau d’esbiaix en l’ús de codons, longitud de les proteïnes codificades, i connectivitat en la xarxa d’interaccions proteïna-proteïna) sobre aquesta correlació. Aquesta anàlisi demostra que la correlació entre la posició a la via i els graus de limitació funcional és independent d’aquests factors. A més, observem que els gens que codifiquen proteïnes que interactuen físicament evolucionen sota seleccions selectives semblants, la qual cosa indica que aquestes proteïnes co-evolucionen. En global, aquests resultats indiquen clarament que els nivells de limitació funcional als què estan sotmesos els gens de la via de la insulina/TOR depenen de la posició que les proteïnes codificades ocupen a la via. Per tant, l’arquitectura de la via té un impacte sobre l’evolució dels seus gens., [eng] Genes are subject to disparate evolutionary forces. One of the goals in Evolutionary Biology is to understand the factors underlying these differences. Genes rarely act in isolation, but they rather operate as elements of complex networks of interacting molecules. Despite the relevance of these networks for understanding gene evolution, the evolutionary properties of these networks remain poorly understood. In this thesis we have studied evolutionary forces (positive and negative selection) that acted on genes involved in the insulin/TOR pathway, and we have related these forces to the position that genes occupy in the pathway. This study has been performed in 12 species of the genus Drosophila, and in 6 vertebrate species. For that purpose, we have (1) identified and annotated the genes involved in this pathway in these species; (2) reconstructed their evolutionary history using phylogenetic analysis; and (3) characterized evolutionary forces that have acted on these genes from the nonsynonymous (dN) to synonymous (dS) divergence ratio (ω = dN/dS). All the studied gene families have at least one representative in all studied species. Furthermore, all studied genes evolve under purifying selection, indicating that they are functional. Therefore, all studied organisms have a complete and functional insulin/TOR pathway. In both Drosophila and vertebrates, we observed that the strength of purifying selection acting on genes correlates with their positions in the pathway, with downstream genes evolving under stronger selective constraint. We evaluated the impact of a number of factors (positive selection, gene expression level and breadth, codon bias, protein length, and connectivity in the protein-protein interaction network) on the observed correlation. This analysis shows that the correlation between pathway position and the strength of purifying selection is independent of these factors. Furthermore, we observed that genes encoding proteins that physically interact evolve under similar selective pressures, which indicates that these proteins co-evolve. Taken together, these results clearly indicate that levels of selective constraint acting on genes of the insulin/TOR pathway are affected by the position that their encoded products occupy in the pathway. Therefore, the structure of the pathway has an effect on the patterns of molecular evolution of its components.

Aquesta recerca pretén ser una primera aproximació a l’objectiu d’esbrinar si el tractament de la teoria de l’evolució als mitjans de comunicació a l’Espanya del franquisme i la transició pot ser un baròmetre a través del qual poder rastrejar l’estat de la societat espanyola i la seva evolució. Aquesta recerca serà restringida, com a primera prospecció, a l’anàlisi dels articles sobre teoria de l’evolució publicats a La Vanguardia Española entre els anys 1939 i 1978. En l’anàlisi s’ha tingut en compte tant articles que se centren en l’evolucionisme biològic, com aquells que hi fan referència en el tractament d’altres temes, com els que simplement l’esmenten en el seu discurs. D’aquesta manera es pretén aconseguir una visió àmplia de l’abast de l’apropiació del concepte d’evolució en la quotidianitat del discurs popular i de l’ús de la teoria com a instrument ideològic. L’estudi dels usos lingüístics, conceptuals i estratègics de la teoria en el discurs periodístic d’aquest període apunta un reflex entre les preocupacions i situació política de la societat del moment i el tractament de la teoria de l’evolució, resultat punt de partida que mereix ser estudiat i contrastat amb més profunditat per tal de poder-ne establir una generalitat.

El treball mostra les relacions que van existir entre la lingüística en els seus inicis i les teories de la biologia, fent una menció especial a les teories de Charles Darwin sobre l'evolució. A més, també es presenta un petit esbós sobre la seva possible actualitat.

Los dientes de los vertebrados, y especialmente de los mamíferos, muestran una gran diversidad de formas como resultado de las adaptaciones ecológicas y alimentarias de las especies en función del hábitat y las condiciones ecológicas. La anatomía dental es de gran utilidad para definir especies y caracterizar poblaciones, y se ha utilizado extensamente para definir nuevos taxones y establecer relaciones filogenéticas. Nuestras investigaciones sobre la evolución morfológica de la dentición de los homininos han puesto de relieve la importancia de los dientes en la caracterización de las adaptaciones ecológicas de nuestros antepasados. El presente trabajo es el primero de una serie de tres trabajos que nos planteamos sobre la importancia de las características anatómicas en la interpretación de la evolución de nuestro linaje. En él se describen los principales eventos evolutivos que dieron origen a los dientes y su diversificación.

The integrin-mediated adhesion machinery is the primary cell-matrix adhesion mechanism in Metazoa. The integrin adhesion complex, which modulates important aspects of the cell physiology, is composed of integrins (alpha and beta subunits) and several scaffolding and signaling proteins. Integrins appeared to be absent in all non-metazoan eukaryotes so-far analyzed, including fungi, plants and choanoflagellates, the sister-group to Metazoa. Thus, integrins and, therefore, the integrin-mediated adhesion and signaling mechanism was considered a metazoan innovation. Recently, a broad comparative genomic analysis including new genome data from several unicellular organisms closely related to fungi and metazoans shattered previous views. The integrin adhesion and signaling complex is not specific to Metazoa, but rather it is present in apusozoans and holozoan protists. Thus, this important signaling and adhesion system predated the origin of Fungi and Metazoa, and was subsequently lost in fungi and choanoflagellates. This finding suggests that cooption played a more important role in the origin of Metazoa than previously believed. Here, we hypothesize that the integrin adhesome was ancestrally involved in signaling.

The development of mainstream research on the origin of life as an outcome of Darwinian evolution is discussed. It is argued that prebiotic evolution and the origin of life should not be excluded from the syllabus and should be part of classes on biological evolution, and that the transition from non-living to living matter is best understood when seen as part of evolutionary biology. The wide acceptance of evolutionary approaches to the study of the emergence of life in European and Latin American countries is discussed.

La densa història del concepte d’evolució arrossega tòpics, errors i sovint la ignorància de les últimes descobertes. Per això és bo que el coneixement del que representa l’evolució fora de l’àmbit acadèmic sigui motiu de revisió periòdica. Un 150è aniversari és una bonica ocasió. La present guia és un bon exemple de col·laboració entre l’estament científic i la comunitat educativa, en la cerca d’una fructífera via de comunicació entre ciència i educació. Una col·laboració que, com es podia esperar, ha donat uns resultats de gran qualitat. L’entusiasme que han mostrat els responsables de l’IMEB i del CDEC ha estat decisiu per portar a bon port aquest projecte. De manera complementària als textos disponibles per a l’acció educativa, hem volgut proporcionar uns quants arguments bàsics per refrescar les nocions essencials de l’evolució a la llum del coneixement actual de la ciència. Però, a més, en el cas de l’evolució, la permeabilitat d’aquest concepte a diverses fonts de coneixement fa especialment atractiva la possibilitat de superar les barreres existents entre les diverses disciplines. La filosofia i la religió, per exemple, són dos camps del coneixement que, intervenint- hi, fan més interessant la discussió sobre el que significa “evolució” i enriqueixen un debat en el qual participa, evidentment, la ciència. Ara bé, alguns corrents d’opinió malden per enverinar aquest debat contaminant la ciència com a tal amb creences d’altres camps. Fa un trist favor a la religió o la filosofia el qui pretén revestir-les de ciència. La matèria primera de la ciència són exclusivament les hipòtesis que es puguin provar o refutar, mentre que l’espiritualitat pertany a una altra dimensió, tan humana com la recerca científica, però diferent.

[cat] El gènere "Artemisia és un dels més grans, pel que fa a nombre d'espècies, de la família de les Asteraceae i és àmpliament distribuït, principalment a l'hemisferi nord, on ocupa hàbitats molt diversos. Algunes de les seves espècies tenen una gran importància econòmica pels seus usos medicinals, alimentaris i ornamentals entre d'altres. El gènere és força conegut des del punt de vista de la seva composició química, però la manca d'estudis biològics generals sobre el gènere i les relacions entre les seves espècies ha sigut la raó per la qual hem dut a terme aquesta tesi doctoral.Aquest estudi comprèn treballs de filogènia molecular basats en la seqüenciació de regions del DNA nuclear i cloroplàstic, que delimiten el subgènere Dracunculus respecte dels altres quatre subgèneres d'Artemisia i estableixen les relaciones entre les espècies que el formen. Les reconstruccions filogenètiques han servit com a marc de discussió per a la resta d'aproximacions, que comprenen estudis cariològics, citogenètics i palinològics i han permès d'establir hipòtesis sobre la colonització del continent sud-americà. S'han realitzat nombrosos recomptes cromosòmicos, molts cops nous per als tàxons concernits, entre ells el primer en el nivell de ploïdia més alt conegut fins ara en el gènere, 16x. Cal destacar a més l'estudi de la grandària del genoma, que estableix un comportament de saturació en l'augment de la quantitat de DNA nuclear en els poliploides i un límit superior per a aquest paràmetre en el gènere. Els estudis sobre les regions 5S i 45S del DNA ribosòmic, duts a terme amb la tècnica d'hibridació in situ fluorescent (FISH), han suggerit l'existència d'un possible model ancestral per al gènere Artemisia quant a la distribució de l'rDNA. L'evolució del genoma d'aquestes espècies ha d'entendre's com el resultat de nombroses reorganitzacions cromosòmiques i de processos de poliploïdització i d'hibridació. També s'ha realitzat una caracterització morfomètrica i microestructural del pol·len del gènere Ajania, així com d'altres Artemisiinae relacionades. Hem confirmat la coexistència dels dos tipus pol·línics descrits a la subtribu, Anthemis i Artemisia, essent el primer el que caracteriza el gènere Ajania. Amb aquestes dades, i en el marc d'una filogènia de la subtribu, podem suggerir que probablement hi ha hagut un canvi del tipus Anthemis (ancestral) al tipus Artemisia (derivat), fet que troba el suport del canvi de la síndrome de pol·linització, d'entomòfila a anemòfila., [eng] The genus Artemisia is one of the largest of the Asteraceae family. It is widely distributed, mainly in the northern hemisphere, where it occupies very different habitats. Some of the species have economic importance for their medicinal uses, as well as for food and ornamental purposes among others. The genus is well known from the standpoint of their chemical composition, but the lack of general biological studies and the poor knowledge of the relationships among its species has been the reason why we have conducted the present thesis.The present study includes a molecular phylogeny based on nuclear and chloroplast DNA regions, which circumscribes the subgenus Dracunculus within the genus Artemisia, studying in depth the relationships between the species of the subgenus. Other phylogenetic reconstructions have been used as frameworks for discussion in different approaches, including karyological, cytogenetic and pollen studies, allowing us to establish, among others, hypotheses about the colonization of South America. Many chromosome counts have been carried out, often related to new taxa, including the first report of the highest ploidy level in the genus to date, 16x (2n = 144 chromosomes). The thesis also includes the study of genome size. The results obtained seem to indicate that the increase of nuclear DNA amount across ploidy levels follows a saturation behaviour according to the Michaelis-Menten function, and a theoretical upper limit for this parameter is hypothesized for the genus. Studies on 5S and 45S regions of ribosomal DNA, carried out with the technique of fluorescent in situ hybridization (FISH) have suggested the existence of different patterns of rDNA distribution in complexes such as the annual representatives of the genus, the subgenus Dracunculus and in the polyploid species on the genus Artemisia. Genome evolution of these species should be understood as the result of numerous chromosomal rearrangements and processes of hybridization and polyploidization. We have also performed a morphometrical and microstructural characterization of the pollen in the genus Ajania and other related Artemisiinae. We have confirmed the coexistence of the two pollen types described in the subtribe, Anthemis and Artemisia, the former being the one that characterizes the genus Ajania. With these data, and in the context of a phylogeny of the subtribe, we suggest that there has probably been a change from the Anthemis type (ancestral) to Artemisia type (derived), a fact which is also supported by the change in the pollination syndrome from entomophily to anemophily.

Conferència pronunciada a la sala d'actes de les Fac. Biociències i Ciències amb motiu de la celebració de Sant Albert, UAB, 18-11-2009

El bicentenari del naixement de Charles Darwin, celebrat durant el passat any 2009, va provocar un considerable augment de l'interés informatiu de la figura del naturalista anglès. En aquest article s'analitza la cobertura informativa d'aquest aniversari en onze diaris generalistes espanyols, i s'estableix grosso modo quines són les principals postures de la premsa espanyola davant de la teoria de l'evolució. D'aquesta anàlisi, queda ben palès com el creacionisme és encara molt viu en els mitjans espanyols més conservadors., The bicentenary of Charles Darwin’s birth, celebrated in 2009, caused a surge in the interest shown by the press in the life and work of the renowned English naturalist. This article analyzes the press coverage devoted to the Darwin Year in eleven Spanish daily papers during the week of Darwin’s birthday and provides a brief synopsis of the positions adopted by the Spanish press regarding the theory of evolution. The analysis makes very clear the relatively strong support for creationism by the conservative press in Spain.

Una de les teories més apassionants i alhora més controvertides dels darrers temps és, sens dubte, la de l'evolució. Segur que tothom ha observat algun arbre evolutiu -o filogenètic-, on a partir d'un tronc comú, el que marca l'origen únic de la vida a la terra, es van ramificant els diversos llinatges d'éssers vius, agrupats en funció del seu parentesc, és a dir, del temps que fa que va viure el seu darrer avantpassat comú.