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Intra-locus sexual conflict, or sexual antagonism, occurs when alleles have opposing fitness effects in thetwo sexes. Previous theory suggests that sexual antagonism is a driver of genetic variation by generating bal-ancing selection. However, these studies assume that populations are well-mixed, neglecting the effects ofspatial subdivision. Here we use mathematical modelling to show that limited dispersal can fundamentallychange evolution at sexually antagonistic autosomal and X-linked loci due to inbreeding and sex-specific kincompetition. We find that if the sexes disperse at different rates, kin competition within the philopatric sexbiases intralocus conflict in favour of the more dispersive sex. Furthermore, kin competition diminishes thestrength of balancing selection relative to genetic drift, reducing genetic variation in small subdivided pop-ulations. Meanwhile, by decreasing heterozygosity, inbreeding reduces the scope for sexually antagonisticpolymorphism due to non-additive allelic effects, and this occurs to a greater extent on the X-chromosomethan autosomes. Overall, our results demonstrate that spatial structure is an important factor in predictingwhere to expect sexually antagonistic alleles. We suggest that observed interspecific and intragenomic varia-tion in sexual antagonism may be explained by sex-specific dispersal ecology and demography.

This work is comparing browser-based and computer installed digital logic circuit simulators, which can be used in for learning digital logic. Theory section introduces basics of combinational and sequential logic.Digitaalipiirisimulaattorien vertailu opetuskäytössä. Tiivistelmä. Kandidaatin tutkielmassa verrataan Internet-selaimissa toimivia pohjaisia ja tietokoneelle valmiiksi asennettuja digitaalipiirien logiikkasimulaattoreita opetuskäytössä, huomioiden suorituskyky, helppokäyttöisyys ja eri ominaisuuksia logiikkapiirien kuvaamiseen. Teoriaosiossa esitellään kombinaatio-, sekä sekvenssilogiikan perusteita.

Similar patterns of genomic divergence have been observed in the evolution of plant species separated by oceans.

Birds, mammals, and certain fishes, including tunas, opahs and lamnid sharks, are endothermic, conserving internally generated, metabolic heat to maintain body or tissue temperatures above that of the environment. Bluefin tunas, among the most threatened, but commercially important, fishes worldwide are renowned regional endotherms, maintaining elevated temperatures of the oxidative locomotor muscle, viscera, brain and eyes, and occupying cold, productive high-latitude waters. Less cold-tolerant tuna, such as yellowfin, by contrast, remain in warm-temperate to tropical waters year-round, reproducing more rapidly than temperate bluefin tuna. Thereby, they are more resilient to fisheries, whereas bluefins have declined steeply. Despite the importance of these traits to not only fisheries, but response to climate change, little is known of the genetic processes underlying the diversification of tuna. In collecting and analysing sequence data across 29,556 genes, we found that parallel selection on standing genetic variation has driven the evolution of endothermy in bluefin tunas. This includes two shared substitutions in genes encoding glycerol-3 phosphate dehydrogenase, an enzyme which underlies thermogenesis in bumblebees and mammals, as well as four genes involved in the Krebs cycle, oxidative phosphorylation, β-oxidation and superoxide removal. Using phylogenetic techniques, we further illustrate that the eight Thunnus species are genetically distinct, but found evidence of mitochondrial genome introgression across two species. Phylogeny-based metrics highlight conservation needs for some of these species.

The kentia palm (Howea forsteriana) is endemic to a 12 km2 volcanic island in the Tasman Sea, Lord Howe Island. It is one of the most traded houseplants in the world. The typical kentia palm presents a dark green-coloured stem. Note that the stem is made of leaf rachis and petioles, which are intermingled towards the base. However, we discovered on Lord Howe Island a new biological variety that has a red stem. Red-stemmed palm species are known and highly demanded as decorative plants. However, these red palm horticultural varieties require tropical or subtropical conditions to grow, hence commercialization is limited. Thus, a red-stemmed variety of H. forsteriana may have tremendous market potential. Nonetheless, palm trees grow generally slowly and often reach maturity at 15–20 years old or later, which may make conventional strategies unsuitable for the propagation of a new variety. This difficulty needs to be addressed before commercialization can be achieved. Here, we found that anthocyanin is responsible for the red colouration of the stem in the new variety. Using RNA sequencing and quantitative PCR, we identified two gene isoforms displaying altered expression associated with this red colouration, encoding a cytochrome b561 and a chalcone synthase. The latter protein is known to be part of the anthocyanin biosynthesis pathway, which plays a central role in pigmentation in plants. The levels of cytochrome b561 transcripts accumulated were found to be well correlated with an increased anthocyanin concentration in the red stems.

Among birds, white-eyes (genus Zosterops) have diversified so extensively that Jared Diamond and Ernst Mayr referred to them as the "great speciator." The Zosterops lineage exhibits some of the fastest rates of species diversification among vertebrates, and its members are the most prolific passerine island colonizers. We present a high-quality genome assembly for the silvereye (Zosterops lateralis), a white-eye species consisting of several subspecies distributed across multiple islands. We investigate the genetic basis of rapid diversification in white-eyes by conducting genomic analyses at varying taxonomic levels. First, we compare the silvereye genome with those of birds from different families and searched for genomic features that may be unique to Zosterops. Second, we compare the genomes of different species of white-eyes from Lifou island (South Pacific), using whole genome resequencing and restriction site associated DNA. Third, we contrast the genomes of two subspecies of silvereye that differ in plumage color. In accordance with theory, we show that white-eyes have high rates of substitutions, gene duplication, and positive selection relative to other birds. Below genus level, we find that genomic differentiation accumulates rapidly and reveals contrasting demographic histories between sympatric species on Lifou, indicative of past interspecific interactions. Finally, we highlight genes possibly involved in color polymorphism between the subspecies of silvereye. By providing the first whole-genome sequence resources for white-eyes and by conducting analyses at different taxonomic levels, we provide genomic evidence underpinning this extraordinary bird radiation.

Summary Microbes can have profound effects on their hosts, driving natural selection, promoting speciation and determining species distributions. However, soil‐dwelling microbes are rarely investigated as drivers of evolutionary change in plants.We used metabarcoding and experimental manipulation of soil microbiomes to investigate the impact of soil and root microbes in a well‐known case of sympatric speciation, the Howea palms of Lord Howe Island (Australia). Whereas H. forsteriana can grow on both calcareous and volcanic soils, H. belmoreana is restricted to, but more successful on, volcanic soil, indicating a trade‐off in adaptation to the two soil types.We suggest a novel explanation for this trade‐off. Arbuscular mycorrhizal fungi (AMF) are significantly depleted in H. forsteriana on volcanic soil, relative to both H. belmoreana on volcanic soil and H. forsteriana on calcareous soil. This is mirrored by the results of survival experiments, where the sterilization of natural soil reduces Howea fitness in every soil–species combination except H. forsteriana on volcanic soil. Furthermore, AMF‐associated genes exhibit evidence of divergent selection between Howea species.These results show a mechanism by which divergent adaptation can have knock‐on effects on host–microbe interactions, thereby reducing interspecific competition and promoting the coexistence of plant sister species., See also the Commentary on this article by Geml & Wagner, 217: 965–967.

Although the presence/absence of aquatic invertebrates using environmental DNA (eDNA) has been established for several species, inferring population densities has remained problematic. The invasive American signal crayfish, Pacifastacus leniusculus (Dana), is the leading cause of decline in the UK's only native crayfish species, Austropotamobius pallipes (Lereboullet). Methods to detect species at low abundances offer the opportunity for the early detection, and potential eradication, of P. leniusculus before population densities reach threatening levels in areas occupied by A. pallipes. Using a factorial experimental design with aquaria, we investigated the impacts of biomass, sex ratio, and fighting behavior on the amount of eDNA released by P. leniusculus, with the aim to infer density per aquarium depending on treatments. The amount of target eDNA in water samples from each aquarium was measured using the quantitative Polymerase Chain Reaction. We show that the presence of eggs significantly increases the concentration of crayfish eDNA per unit of mass, and that there is a significant relationship between eDNA concentration and biomass when females are egg-bearing. However, the relationship between crayfish biomass and eDNA concentration is lost in aquaria without ovigerous females. Female-specific tanks had significantly higher eDNA concentrations than male-specific tanks, and the prevention of fighting did not impact the amount of eDNA in the water. These results indicate that detection and estimate of crayfish abundance using eDNA may be more effective while females are ovigerous. This information should guide further research for an accurate estimation of crayfish biomass in the field depending on the season. Our results indicate that detection and quantification of egg-laying aquatic invertebrate species using eDNA could be most successful during periods when eggs are developing in the water. We recommend that practitioners consider the reproductive cycle of target species when attempting to study or detect aquatic species using eDNA in the field.

Monocots account for a quarter of angiosperm species richness and are among the most economically and culturally important plants, including cereals (grasses), palms, orchids and lilies. Previous investigations of correlates of monocot species diversity have varied in scale and usually concentrated on a few drivers of diversification. Here, to disentangle the correlates of monocot diversity, we reconstructed a genus-level phylogenetic tree (1987 of the 2713 genera) and compiled an extensive database of abiotic, biotic and geographical characteristics to assess whether differences in these traits correlate with the vast asymmetrical species richness among genera present in this clade. Our results support several classical biodiversity theories, including species–area relationships, and latitudinal and elevational diversity gradients. Furthermore, interactions among these factors explain an additional 10% of the variation (compared to 36% from the main effects alone). We conclude that higher species richness among monocot genera is associated with geographical variables, especially larger ranges and lower elevations, rather than physical environment or physiology.

Ecological speciation requires divergent selection, reproductive isolation and a genetic mechanism to link the two. We examined the role of gene expression and coding sequence evolution in this process using two species of Howea palms that have diverged sympatrically on Lord Howe Island, Australia. These palms are associated with distinct soil types and have displaced flowering times, representing an ideal candidate for ecological speciation. We generated large amounts of RNA‐Seq data from multiple individuals and tissue types collected on the island from each of the two species. We found that differentially expressed loci as well as those with divergent coding sequences between Howea species were associated with known ecological and phenotypic differences, including response to salinity, drought, pH and flowering time. From these loci, we identified potential ‘ecological speciation genes’ and further validate their effect on flowering time by knocking out orthologous loci in a model plant species. Finally, we put forward six plausible ecological speciation loci, providing support for the hypothesis that pleiotropy could help to overcome the antagonism between selection and recombination during speciation with gene flow.

Among birds, white-eyes (genus Zosterops) have diversified so extensively that Jared Diamond and Ernst Mayr referred to them as the “great speciator.” The Zosterops lineage exhibits some of the fastest rates of species diversification among vertebrates, and its members are the most prolific passerine island colonizers. We present a high-quality genome assembly for the silvereye (Zosterops lateralis), a white-eye species consisting of several subspecies distributed across multiple islands. We investigate the genetic basis of rapid diversification in white-eyes by conducting genomic analyses at varying taxonomic levels. First, we compare the silvereye genome with those of birds from different families and searched for genomic features that may be unique to Zosterops. Second, we compare the genomes of different species of white-eyes from Lifou island (South Pacific), using whole genome resequencing and restriction site associated DNA. Third, we contrast the genomes of two subspecies of silvereye that differ in plumage color. In accordance with theory, we show that white-eyes have high rates of substitutions, gene duplication, and positive selection relative to other birds. Below genus level, we find that genomic differentiation accumulates rapidly and reveals contrasting demographic histories between sympatric species on Lifou, indicative of past interspecific interactions. Finally, we highlight genes possibly involved in color polymorphism between the subspecies of silvereye. By providing the first whole-genome sequence resources for white-eyes and by conducting analyses at different taxonomic levels, we provide genomic evidence underpinning this extraordinary bird radiation.

It is thought that speciation in phytophagous insects is often due to colonization of novel host plants, because radiations of plant and insect lineages are typically asynchronous. Recent phylogenetic comparisons have supported this model of diversification for both insect herbivores and specialized pollinators. An exceptional case where contemporaneous plant insect diversification might be expected is the obligate mutualism between fig trees (Ficus species, Moraceae) and their pollinating wasps (Agaonidae, Hymenoptera). The ubiquity and ecological significance of this mutualism in tropical and subtropical ecosystems has long intrigued biologists, but the systematic challenge posed by >750 interacting species pairs has\ud hindered progress toward understanding its evolutionary history. In particular, taxon sampling and analytical tools have been insufficient for large-scale co-phylogenetic analyses. Here, we sampled nearly 200 interacting pairs of fig and wasp species from across the globe. Two\ud supermatrices were assembled: on average, wasps had sequences from 77% of six genes (5.6kb), figs had sequences from 60% of five genes (5.5 kb), and overall 850 new DNA sequences were generated for this study. We also developed a new analytical tool, Jane 2, for event-based phylogenetic reconciliation analysis of very large data sets. Separate Bayesian\ud phylogenetic analyses for figs and fig wasps under relaxed molecular clock assumptions indicate Cretaceous diversification of crown groups and contemporaneous divergence for nearly half of all fig and pollinator lineages. Event-based co-phylogenetic analyses further support the co-diversification hypothesis. Biogeographic analyses indicate that the presentday distribution of fig and pollinator lineages is consistent with an Eurasian origin and subsequent dispersal, rather than with Gondwanan vicariance. Overall, our findings indicate that the fig-pollinator mutualism represents an extreme case among plant-insect interactions of coordinated dispersal and long-term co-diversification.