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Distyly is an iconic floral polymorphism governed by a supergene, which promotes efficient pollen transfer and outcrossing through reciprocal differences in the position of sexual organs in flowers, often coupled with heteromorphic self-incompatibility. Distyly has evolved convergently in multiple flowering plant lineages, but has also broken down repeatedly, often resulting in homostylous, self-compatible populations with elevated rates of self-fertilization. Here, we aimed to study the genetic causes and genomic consequences of the shift to homostyly in Linum trigynum, which is closely related to distylous Linum tenue. Building on a high-quality genome assembly, we show that L. trigynum harbors a genomic region homologous to the dominant haplotype of the distyly supergene conferring long stamens and short styles in L. tenue, suggesting that loss of distyly first occurred in a short-styled individual. In contrast to homostylous Primula and Fagopyrum, L. trigynum harbors no fixed loss-of-function mutations in coding sequences of S-linked distyly candidate genes. Instead, floral gene expression analyses and controlled crosses suggest that mutations downregulating the S-linked LtWDR-44 candidate gene for male self-incompatibility and/or anther height could underlie homostyly and self-compatibility in L. trigynum. Population genomic analyses of 224 whole-genome sequences further demonstrate that L. trigynum is highly self-fertilizing, exhibits significantly lower genetic diversity genome-wide, and is experiencing relaxed purifying selection and less frequent positive selection on nonsynonymous mutations relative to L. tenue. Our analyses shed light on the loss of distyly in L. trigynum, and advance our understanding of a common evolutionary transition in flowering plants.

Angiosperms are the cornerstone of most terrestrial ecosystems and human livelihoods1,2. A robust understanding of angiosperm evolution is required to explain their rise to ecological dominance. So far, the angiosperm tree of life has been determined primarily by means of analyses of the plastid genome3,4. Many studies have drawn on this foundational work, such as classification and first insights into angiosperm diversification since their Mesozoic origins5,6,7. However, the limited and biased sampling of both taxa and genomes undermines confidence in the tree and its implications. Here, we build the tree of life for almost 8,000 (about 60%) angiosperm genera using a standardized set of 353 nuclear genes8. This 15-fold increase in genus-level sampling relative to comparable nuclear studies9 provides a critical test of earlier results and brings notable change to key groups, especially in rosids, while substantiating many previously predicted relationships. Scaling this tree to time using 200 fossils, we discovered that early angiosperm evolution was characterized by high gene tree conflict and explosive diversification, giving rise to more than 80% of extant angiosperm orders. Steady diversification ensued through the remaining Mesozoic Era until rates resurged in the Cenozoic Era, concurrent with decreasing global temperatures and tightly linked with gene tree conflict. Taken together, our extensive sampling combined with advanced phylogenomic methods shows the deep history and full complexity in the evolution of a megadiverse clade.

Linum suffruticosum s.l. is a taxonomic complex widespread in the Western Mediterranean basin. The complex is characterized by a high phenotypic and cytogenetic diversity, and by a unique three-dimensional heterostyly system that makes it an obligate outcrosser. We studied the patterns of genetic diversity and structure of populations throughout the entire distribution of L. suffruticosum s.l. with microsatellite markers. We analysed their relationships with various biological and ecological variables, including the morph ratio and sex organ reciprocity of populations measured with a novel multi-dimensional method. Populations consistently showed an approximate 1:1 morph ratio with high sex organ reciprocity and high genetic diversity. We found high genetic differentiation of populations, showing a pattern of isolation by distance. The Rif mountains in NW Africa were the most important genetic barrier. The taxonomic treatment within the group was not related to the genetic differentiation of populations, but to their environmental differentiation. Genetic diversity was unrelated to latitude, elevation, population size, niche suitability or breeding system. However, there was a clear influence of ploidy level on the genetic diversity of populations, and a seeming centre–periphery pattern in its distribution. Our results suggest that polyploidization events, high outcrossing rates, isolation by distance and important geographical barriers to gene flow have played major roles in the microevolutionary history of this species complex.

When colonizing new ranges, plant populations may benefit from the absence of the checks imposed by the enemies, herbivores, and pathogens that regulated their numbers in their original range. Therefore, rates of plant damage or infestation by natural enemies are expected to be lower in the new range. Exposing both non-native and native plant populations in the native range, where native herbivores are present, can be used to test whether resistance mechanisms have diverged between populations. Datura stramonium is native to the Americas but widely distributed in Spain, where populations show lower herbivore damage than populations in the native range. We established experiments in two localities in the native range (Mexico), exposing two native and two non-native D. stramonium populations to natural herbivores. Plant performance differed between the localities, as did the abundance of the main specialist herbivore, Lema daturaphila. In Teotihuacán, where L. daturaphila is common, native plants had significantly more adult beetles and herbivore damage than non-native plants. The degree of infestation by the specialist seed predator Trichobaris soror differed among populations and between sites, but the native Ticumán population always had the lowest level of infestation. The Ticumán population also had the highest concentration of the alkaloid scopolamine. Scopolamine was negatively related to the number of eggs deposited by L. daturaphila in Teotihuacán. There was among-family variation in herbivore damage (resistance), alkaloid content (scopolamine), and infestation by L. daturaphila and T. soror, indicating genetic variation and potential for further evolution. Although native and non-native D. stramonium populations have not yet diverged in plant resistance/constitutive defense, the differences between ranges (and the two experimental sites) in the type and abundance of herbivores suggest that further research is needed on the role of resource availability and a

Since the insights by Charles Darwin, heterostyly, a floral polymorphism with morphs bearing stigmas and anthers at reciprocal heights, has become a model system for the study of natural selection. Based on his archetypal heterostylous flower, including regular symmetry, few stamens and a tube, Darwin hypothesised that heterostyly evolved to promote outcrossing through efficient pollen transfer between morphs involving different areas of a pollinator’s body, thus proposing his seminal pollination-precision hypothesis. Here we update the number of heterostylous and other style-length polymorphic taxa to 247 genera belonging to 34 families, notably expanding known cases by 20%. Using phylogenetic and comparative analyses across the angiosperms, we show numerous independent origins of style-length polymorphism associated with actinomorphic, tubular flowers with a low number of sex organs, stamens fused to the corolla, and pollination by long-tongued insects. These associations provide support for the Darwinian pollination-precision hypothesis as a basis for convergent evolution of heterostyly across angiosperms.

No living being is an island. Every creature needs resources from its environment to survive and thrive throughout its life. But in a finite world with over 8.7 million species, acquiring such resources is an inherently competitive endeavour. This has resulted in an extraordinary diversity of interactions, with varying strengths that have either negative or positive consequences for species’ performance. Over the last century, ecologists have sought to understand how the balance of these interactions affects a species’ ability to persist in a community. Initially, research focused on studying interactions between pairs of species, finding that coexistence is possible when stabilising niche differences, which occur when intraspecific competition exceeds interspecific competition, outweigh fitness differences that favour one competitor over others. However, species typically engage in interactions that go beyond species pairs, making this pairwise framework unsuitable to explore species persistence in complex communities. Besides, one main characteristic of ecological interactions is that they are not set in stone—on the contrary, they vary through space and time in response to modifications in the surrounding conditions. Therefore, new theoretical developments are providing us with tools to comprehend how interactions shape biodiversity in complex, multispecies communities with environmental heterogeneity, which is of paramount importance in the changing world that we inhabit. In this thesis, I combine the most recent advances in ecological theory with thorough empirical data to explore how different sources of environmental heterogeneity alter biotic interactions between plant species, and in turn how the structure of such interactions shapes the determinants of multispecies coexistence. In the first three chapters, I use a structural stability approach that allows me to investigate the mechanisms of coexistence beyond pairwise combinations of species. In chapter on

Premise: Divergence of floral morphology and breeding systems are often expected to be linked to angiosperm diversification and environmental niche divergence. However, available evidence for such relationships remain idiosyncratic, due to different taxonomic, geographical and time scales. The Palearctic genus Helianthemum shows the highest diversity of the family Cistaceae in terms of breeding systems, floral traits and environmental conditions, resulting from three recent evolutionary radiations occurred since the Late Miocene. Here, we investigate the tempo and mode of evolution of floral morphology in the genus, and its link with species diversification and environmental niche divergence. Methods: We quantified eighteen floral traits from 83 taxa and applied phylogenetic comparative methods using a robust phylogenetic framework based on genotyping by sequencing data. Results: The results revealed three different floral morphologies, putatively related to three different breeding systems: (i) type I, characterized by small flowers without herkogamy and low pollen to ovule ratio; (ii) type II, represented by large flowers with approach herkogamy and intermediate pollen to ovule ratio; and (iii) type III, featured by small flowers with reverse herkogamy and the highest pollen to ovule ratio. Each morphology has been highly conserved across each radiation and has evolved independently of species diversification and ecological niche divergence. Conclusions: The combined results of trait, niche and species diversification ultimately recovered a pattern of potentially non-adaptive radiations in Helianthemum and highlight the idea that evolutionary radiations can be decoupled from floral morphology evolution even in lineages that diversified in heterogeneous environments as the Mediterranean Basin.

Background: Microsatellite markers were developed for distylous Linum suffruticosum and tested in the monomorphic sister species Linum tenuifolium. These species are perennial herbs endemic to the western and northwestern Mediterranean, respectively, with a partially overlapping distribution area. Methods and results: We developed 12 microsatellite markers for L. suffruticosum using next generation sequencing, and assessed their polymorphism and genetic diversity in 152 individuals from seven natural populations. The markers displayed high polymorphism, with two to 16 alleles per locus and population, and average observed and expected heterozygosities of 0.833 and 0.692, respectively. All loci amplified successfully in the sister species L. tenuifolium, and 150 individuals from seven populations were also screened. The polymorphism exhibited was high, with two to ten alleles per locus and population, and average observed and expected heterozygosities of 0.77 and 0.62, respectively. Conclusions: The microsatellite markers identified in L. suffruticosum and tested in L. tenuifolium are a powerful tool to facilitate future investigations of the population genetics, mating patterns and hybridization between both Linum species in their contact zone.

Premise: Divergence of floral morphology and breeding systems are often expected to be linked to angiosperm diversification and environmental niche divergence. However, available evidence for such relationships is not generalizable due to different taxonomic, geographical and time scales. The Palearctic genus Helianthemum shows the highest diversity of the family Cistaceae in terms of breeding systems, floral traits, and environmental conditions as a result of three recent evolutionary radiations since the Late Miocene. Here, we investigated the tempo and mode of evolution of floral morphology in the genus and its link with species diversification and environmental niche divergence. Methods: We quantified 18 floral traits from 83 taxa and applied phylogenetic comparative methods using a robust phylogenetic framework based on genotyping-by-sequencing data. Results: We found three different floral morphologies, putatively related to three different breeding systems: type I, characterized by small flowers without herkogamy and low pollen to ovule ratio; type II, represented by large flowers with approach herkogamy and intermediate pollen to ovule ratio; and type III, featured by small flowers with reverse herkogamy and the highest pollen to ovule ratio. Each morphology has been highly conserved across each radiation and has evolved independently of species diversification and ecological niche divergence. Conclusions: The combined results of trait, niche, and species diversification ultimately recovered a pattern of potentially non-adaptive radiations in Helianthemum and highlight the idea that evolutionary radiations can be decoupled from floral morphology evolution even in lineages that diversified in heterogeneous environments as the Mediterranean Basin.

Premise: Divergence of floral morphology and breeding systems are often expected to be linked to angiosperm diversification and environmental niche divergence. However, available evidence for such relationships is not generalizable due to different taxonomic, geographical and time scales. The Palearctic genus Helianthemum shows the highest diversity of the family Cistaceae in terms of breeding systems, floral traits, and environmental conditions as a result of three recent evolutionary radiations since the Late Miocene. Here, we investigated the tempo and mode of evolution of floral morphology in the genus and its link with species diversification and environmental niche divergence. Methods: We quantified 18 floral traits from 83 taxa and applied phylogenetic comparative methods using a robust phylogenetic framework based on genotyping-by-sequencing data. Results: We found three different floral morphologies, putatively related to three different breeding systems: type I, characterized by small flowers without herkogamy and low pollen to ovule ratio; type II, represented by large flowers with approach herkogamy and intermediate pollen to ovule ratio; and type III, featured by small flowers with reverse herkogamy and the highest pollen to ovule ratio. Each morphology has been highly conserved across each radiation and has evolved independently of species diversification and ecological niche divergence. Conclusions: The combined results of trait, niche, and species diversification ultimately recovered a pattern of potentially non-adaptive radiations in Helianthemum and highlight the idea that evolutionary radiations can be decoupled from floral morphology evolution even in lineages that diversified in heterogeneous environments as the Mediterranean Basin.

Premise: Divergence of floral morphology and breeding systems are often expected to be linked to angiosperm diversification and environmental niche divergence. However, available evidence for such relationships remain idiosyncratic, due to different taxonomic, geographical and time scales. The Palearctic genus Helianthemum shows the highest diversity of the family Cistaceae in terms of breeding systems, floral traits and environmental conditions, resulting from three recent evolutionary radiations occurred since the Late Miocene. Here, we investigate the tempo and mode of evolution of floral morphology in the genus, and its link with species diversification and environmental niche divergence. Methods: We quantified eighteen floral traits from 83 taxa and applied phylogenetic comparative methods using a robust phylogenetic framework based on genotyping by sequencing data. Results: The results revealed three different floral morphologies, putatively related to three different breeding systems: (i) type I, characterized by small flowers without herkogamy and low pollen to ovule ratio; (ii) type II, represented by large flowers with approach herkogamy and intermediate pollen to ovule ratio; and (iii) type III, featured by small flowers with reverse herkogamy and the highest pollen to ovule ratio. Each morphology has been highly conserved across each radiation and has evolved independently of species diversification and ecological niche divergence. Conclusions: The combined results of trait, niche and species diversification ultimately recovered a pattern of potentially non-adaptive radiations in Helianthemum and highlight the idea that evolutionary radiations can be decoupled from floral morphology evolution even in lineages that diversified in heterogeneous environments as the Mediterranean Basin.

Background and Aims Chromosome evolution leads to hybrid dysfunction and recombination patterns and has thus been proposed as a major driver of diversification in all branches of the tree of life, including flowering plants. In this study we used the genus Linum (flax species) to evaluate the effects of chromosomal evolution on diversification rates and on traits that are important for sexual reproduction. Linum is a useful study group because it has considerable reproductive polymorphism (heterostyly) and chromosomal variation (n = 6–36) and a complex pattern of biogeographical distribution. Methods We tested several traditional hypotheses of chromosomal evolution. We analysed changes in chromosome number across the phylogenetic tree (ChromEvol model) in combination with diversification rates (ChromoSSE model), biogeographical distribution, heterostyly and habit (ChromePlus model). Key Results Chromosome number evolved across the Linum phylogeny from an estimated ancestral chromosome number of n = 9. While there were few apparent incidences of cladogenesis through chromosome evolution, we inferred up to five chromosomal speciation events. Chromosome evolution was not related to heterostyly but did show significant relationships with habit and geographical range. Polyploidy was negatively correlated with perennial habit, as expected from the relative commonness of perennial woodiness and absence of perennial clonality in the genus. The colonization of new areas was linked to genome rearrangements (polyploidy and dysploidy), which could be associated with speciation events during the colonization process. Conclusions Chromosome evolution is a key trait in some clades of the Linum phylogeny. Chromosome evolution directly impacts speciation and indirectly influences biogeographical processes and important plant traits.

Introduction: The high frequency of polyploidy in the evolutionary history of many plant groups occurring in the Mediterranean region is likely a consequence of its dynamic paleogeographic and climatic history. Polyploids frequently have distinct characteristics that allow them to overcome the minority cytotype exclusion. Such traits may enable polyploid individuals to grow in habitats different from their parentals and/or expand to new areas, leading to spatial segregation. Therefore, the successful establishment of polyploid lineages has long been associated with niche divergence or niche partitioning and the ability of polyploids to cope with different, often more stressful, conditions. In this study, we aimed to explore the role of environmental variables associated with the current distribution patterns of cytotypes within the polyploid complex Linum suffruticosum s.l.. Methods: The distribution and environmental niches of the five main cytotypes of Linum suffruticosum s.l. (diploids, tetraploids, hexaploids, octoploids and decaploids) were studied across its distribution range. Realized environmental niche of each cytotype was determined using niche modelling tools, such as maximum entropy modelling and niche equivalency and similarity tests. Results: Differences in the environmental conditions of L. suffruticosum s.l. cytotypes were observed, with polyploids being associated with habitats of increased drought and soil pH, narrower temperature ranges and decreased soil water and cation exchange capacities. Diploids present the widest environmental niche, and polyploids occupy part of the diploid niche. Although some polyploids have equivalent potential ecological niches, cytotypes do not co-occur in nature. Additionally, the ecological niche of this polyploid complex is different between continents, with North African habitats being characterised by differences in soil texture, higher pH, and low cation exchange capacity, precipitation and soil water capacity

Background: Microsatellite markers were developed for distylous Linum suffruticosum and tested in the monomorphic sister species Linum tenuifolium. These species are perennial herbs endemic to the western and northwestern Mediterranean, respectively, with a partially overlapping distribution area. Methods and results: We developed 12 microsatellite markers for L. suffruticosum using next generation sequencing, and assessed their polymorphism and genetic diversity in 152 individuals from seven natural populations. The markers displayed high polymorphism, with two to 16 alleles per locus and population, and average observed and expected heterozygosities of 0.833 and 0.692, respectively. All loci amplified successfully in the sister species L. tenuifolium, and 150 individuals from seven populations were also screened. The polymorphism exhibited was high, with two to ten alleles per locus and population, and average observed and expected heterozygosities of 0.77 and 0.62, respectively. Conclusions: The microsatellite markers identified in L. suffruticosum and tested in L. tenuifolium are a powerful tool to facilitate future investigations of the population genetics, mating patterns and hybridization between both Linum species in their contact zone.

No living being is an island. Every creature needs resources from its environment to survive and thrive throughout its life. But in a finite world with over 8.7 million species, acquiring such resources is an inherently competitive endeavour. This has resulted in an extraordinary diversity of interactions, with varying strengths that have either negative or positive consequences for species’ performance. Over the last century, ecologists have sought to understand how the balance of these interactions affects a species’ ability to persist in a community. Initially, research focused on studying interactions between pairs of species, finding that coexistence is possible when stabilising niche differences, which occur when intraspecific competition exceeds interspecific competition, outweigh fitness differences that favour one competitor over others. However, species typically engage in interactions that go beyond species pairs, making this pairwise framework unsuitable to explore species persistence in complex communities. Besides, one main characteristic of ecological interactions is that they are not set in stone—on the contrary, they vary through space and time in response to modifications in the surrounding conditions. Therefore, new theoretical developments are providing us with tools to comprehend how interactions shape biodiversity in complex, multispecies communities with environmental heterogeneity, which is of paramount importance in the changing world that we inhabit. In this thesis, I combine the most recent advances in ecological theory with thorough empirical data to explore how different sources of environmental heterogeneity alter biotic interactions between plant species, and in turn how the structure of such interactions shapes the determinants of multispecies coexistence. In the first three chapters, I use a structural stability approach that allows me to investigate the mechanisms of coexistence beyond pairwise combinations of species. In chapter on

No living being is an island. Every creature needs resources from its environment to survive and thrive throughout its life. But in a finite world with over 8.7 million species, acquiring such resources is an inherently competitive endeavour. This has resulted in an extraordinary diversity of interactions, with varying strengths that have either negative or positive consequences for species’ performance. Over the last century, ecologists have sought to understand how the balance of these interactions affects a species’ ability to persist in a community. Initially, research focused on studying interactions between pairs of species, finding that coexistence is possible when stabilising niche differences, which occur when intraspecific competition exceeds interspecific competition, outweigh fitness differences that favour one competitor over others. However, species typically engage in interactions that go beyond species pairs, making this pairwise framework unsuitable to explore species persistence in complex communities. Besides, one main characteristic of ecological interactions is that they are not set in stone—on the contrary, they vary through space and time in response to modifications in the surrounding conditions. Therefore, new theoretical developments are providing us with tools to comprehend how interactions shape biodiversity in complex, multispecies communities with environmental heterogeneity, which is of paramount importance in the changing world that we inhabit. In this thesis, I combine the most recent advances in ecological theory with thorough empirical data to explore how different sources of environmental heterogeneity alter biotic interactions between plant species, and in turn how the structure of such interactions shapes the determinants of multispecies coexistence. In the first three chapters, I use a structural stability approach that allows me to investigate the mechanisms of coexistence beyond pairwise combinations of species. In chapter on

Linum suffruticosum L. s.l. (Linaceae) is a taxonomic complex widespread in the western Mediterranean basin. It is characterized by its high cytogenetic diversity and its 3D heterostyly system, which makes it an obligate outcrosser. In this work we studied the patterns of genetic diversity and population structure throughout its distribution using neutral genetic data obtained from microsatellite markers. It is shown that there is no relationship between taxonomic treatment and genetic variability, so a revision of the taxonomy would be useful. L. suffruticosum s.l. has a high level of genetic diversity, promoted by polyploidization processes, and maintained by the existence of abundant and reproductively connected populations. The populations are genetically structured following a pattern of isolation by distance, with the Rif mountains as the most important genetic barrier. However, genetic diversity does not covary at the latitudinal or altitudinal level, nor is it related to population size or the proportion of stylar morphs. This suggests that variations in genetic diversity are not mostly determined by selective forces, but by stochastic processes., Linum suffruticosum L. s.l. (Linaceae) es un complejo taxonómico ampliamente extendido en la cuenca mediterránea occidental. Se caracteriza por su alta diversidad citogenética y su sistema de heterostília en 3D, lo que lo convierte en un outcrosser obligado. En este trabajo se estudian los patrones de diversidad genética y estructura poblacional a lo largo de su distribución utilizando datos genéticos neutros obtenidos a partir de marcadores de microsatélites. Se ha demostrado que no existe relación entre el tratamiento taxonómico y la variabilidad genética, por lo que sería útil una revisión de la taxonomía. L. suffruticosum s.l. presenta una elevada diversidad genética, promovida por procesos de poliploidización, y mantenida por la existencia de poblaciones abundantes y conectadas reproductivamente. Las poblaciones están estructuradas genéticamente siguiendo un patrón de aislamiento por distancia, con las montañas del Rif como la barrera genética más importante. Sin embargo, la diversidad genética no covaría con la latitud o la altitud, ni está relacionada con el tamaño de la población o la proporción de morfos estilares. Esto sugiere que las variaciones en la diversidad genética no están determinadas principalmente por fuerzas selectivas, sino por procesos estocásticos.

Supergenes govern multi-trait-balanced polymorphisms in a wide range of systems; however, our understanding of their origins and evolution remains incomplete. The reciprocal placement of stigmas and anthers in pin and thrum floral morphs of distylous species constitutes an iconic example of a balanced polymorphism governed by a supergene, the distyly S-locus. Recent studies have shown that the Primula and Turnera distyly supergenes are both hemizygous in thrums, but it remains unknown whether hemizygosity is pervasive among distyly S-loci. As hemizygosity has major consequences for supergene evolution and loss, clarifying whether this genetic architecture is shared among distylous species is critical. Here, we have characterized the genetic architecture and evolution of the distyly supergene in Linum by generating a chromosome-level genome assembly of Linum tenue, followed by the identification of the S-locus using population genomic data. We show that hemizygosity and thrum-specific expression of S-linked genes, including a pistil-expressed candidate gene for style length, are major features of the Linum S-locus. Structural variation is likely instrumental for recombination suppression, and although the non-recombining dominant haplotype has accumulated transposable elements, S-linked genes are not under relaxed purifying selection. Our findings reveal remarkable convergence in the genetic architecture and evolution of independently derived distyly supergenes, provide a counterexample to classic inversion-based supergenes, and shed new light on the origin and maintenance of an iconic floral polymorphism.

Supergenes govern multi-trait-balanced polymorphisms in a wide range of systems; however, our understanding of their origins and evolution remains incomplete. The reciprocal placement of stigmas and anthers in pin and thrum floral morphs of distylous species constitutes an iconic example of a balanced polymorphism governed by a supergene, the distyly S-locus. Recent studies have shown that the Primula and Turnera distyly supergenes are both hemizygous in thrums, but it remains unknown whether hemizygosity is pervasive among distyly S-loci. As hemizygosity has major consequences for supergene evolution and loss, clarifying whether this genetic architecture is shared among distylous species is critical. Here, we have characterized the genetic architecture and evolution of the distyly supergene in Linum by generating a chromosome-level genome assembly of Linum tenue, followed by the identification of the S-locus using population genomic data. We show that hemizygosity and thrum-specific expression of S-linked genes, including a pistil-expressed candidate gene for style length, are major features of the Linum S-locus. Structural variation is likely instrumental for recombination suppression, and although the non-recombining dominant haplotype has accumulated transposable elements, S-linked genes are not under relaxed purifying selection. Our findings reveal remarkable convergence in the genetic architecture and evolution of independently derived distyly supergenes, provide a counterexample to classic inversion-based supergenes, and shed new light on the origin and maintenance of an iconic floral polymorphism.

The floral phenotype plays a main role in the attraction and fit of pollinators. Both perianth traits and the positioning of sex organs can be subjected to natural selection and determine nonrandom mating patterns in populations. In stylar-polymorphic species, the Darwinian hypothesis predicts increased mating success between individuals with sex organs at equivalent heights (i.e. with higher reciprocity). We used paternity analyses in experimental populations of a stylar-dimorphic species. By comparing the observed mating patterns with those expected under random mating, we tested the effects of sex organ reciprocity and perianth traits on mating success. We also analysed phenotypic selection on perianth traits through female and male functions. The (dis)similarity of parental perianth traits had no direct effects on the mating patterns. Sex organ reciprocity had a positive effect on mating success. Narrow floral tubes increased this effect in upper sex organs. Perianth traits showed little signs of phenotypic selection. Female and absolute fitness measures resulted in different patterns of phenotypic selection. We provide precise empirical evidence of the Darwinian hypothesis about the functioning of stylar polymorphisms, demonstrating that mating patterns are determined by sex organ reciprocity and only those perianth traits which are critical to pollinator fit.

Supergenes govern multi-trait-balanced polymorphisms in a wide range of systems; however, our understanding of their origins and evolution remains incomplete. The reciprocal placement of stigmas and anthers in pin and thrum floral morphs of distylous species constitutes an iconic example of a balanced polymorphism governed by a supergene, the distyly S-locus. Recent studies have shown that the Primula and Turnera distyly supergenes are both hemizygous in thrums, but it remains unknown whether hemizygosity is pervasive among distyly S-loci. As hemizygosity has major consequences for supergene evolution and loss, clarifying whether this genetic architecture is shared among distylous species is critical. Here, we have characterized the genetic architecture and evolution of the distyly supergene in Linum by generating a chromosome-level genome assembly of Linum tenue, followed by the identification of the S-locus using population genomic data. We show that hemizygosity and thrum-specific expression of S-linked genes, including a pistil-expressed candidate gene for style length, are major features of the Linum S-locus. Structural variation is likely instrumental for recombination suppression, and although the non-recombining dominant haplotype has accumulated transposable elements, S-linked genes are not under relaxed purifying selection. Our findings reveal remarkable convergence in the genetic architecture and evolution of independently derived distyly supergenes, provide a counterexample to classic inversion-based supergenes, and shed new light on the origin and maintenance of an iconic floral polymorphism.

Aim: Understanding plant diversity and how different traits have shaped the current biodiversity setting across the world is one of the major challenges for evolutionary biology. In this sense, genus Linum have been broadly studied as a model of species showing heterostyly, but no studies have attempted to investigate possible correlations between heterostyly and diversification. Thus, in this study we aim to explore the origin and diversification of the genus Linum and to determine its centre of diversity and potential source for the colonisation of other areas. Also, we aim to study how heterostyly may have shaped diversification rates and colonisation patterns in the genus. Location: Worldwide (focused on the Western Palearctic). Taxon: Genus Linum L. (Linaceae). Methods: We analysed nuclear ITS and plastid ndhF, matK and trnL-F DNA regions in a total of 103 samples of 93 different species of the genus Linum, as well as seven samples from other Linaceae. We performed divergence time analysis in BEAST2 under a birth-death tree model, then used the resulting tree for an ancestral area reconstruction using the R package “BioGeoBEARS.” Finally, we estimated diversification rates using BAMM and examined the correlation between diversification rates and geographic ranges and heterostyly. Results: Linum s.l. diverged during the late Eocene to mid Oligocene (27.2–38.29 Ma at 95% highest posterior density interval) in the Western Palearctic, where most species diversified. Within-area speciation is the main mechanism of diversification in the genus. Most dispersal events occurred from the Western Palearctic to other regions, probably through long-distance dispersal (LDD). No changes were found regarding diversification rates in specific clades or in relation with reproductive system (heterostyly) or geographic areas. Colonisation of new areas was achieved mostly by monomorphic lineages, whereas heterostylous species mostly remained in the ancestral Western Paleartic area.

The Mediterranean region is one of the most important worldwide hotspots in terms of number of species and endemism, and multiple hypotheses have been proposed to explain how diversification occurred in this area. The contribution of different traits to the diversification process has been evaluated in different groups of plants. In the case of Centaurium (Gentianaceae), a genus with a center of diversity placed in the Mediterranean region, polyploidy seems to have been an important driver of diversification as more than half of species are polyploids.

Aim: Understanding plant diversity and how different traits have shaped the current biodiversity setting across the world is one of the major challenges for evolutionary biology. In this sense, genus Linum have been broadly studied as a model of species showing heterostyly, but no studies have attempted to investigate possible correlations between heterostyly and diversification. Thus, in this study we aim to explore the origin and diversification of the genus Linum and to determine its centre of diversity and potential source for the colonisation of other areas. Also, we aim to study how heterostyly may have shaped diversification rates and colonisation patterns in the genus. Location: Worldwide (focused on the Western Palearctic). Taxon: Genus Linum L. (Linaceae). Methods: We analysed nuclear ITS and plastid ndhF, matK and trnL-F DNA regions in a total of 103 samples of 93 different species of the genus Linum, as well as seven samples from other Linaceae. We performed divergence time analysis in BEAST2 under a birth-death tree model, then used the resulting tree for an ancestral area reconstruction using the R package “BioGeoBEARS.” Finally, we estimated diversification rates using BAMM and examined the correlation between diversification rates and geographic ranges and heterostyly. Results: Linum s.l. diverged during the late Eocene to mid Oligocene (27.2–38.29 Ma at 95% highest posterior density interval) in the Western Palearctic, where most species diversified. Within-area speciation is the main mechanism of diversification in the genus. Most dispersal events occurred from the Western Palearctic to other regions, probably through long-distance dispersal (LDD). No changes were found regarding diversification rates in specific clades or in relation with reproductive system (heterostyly) or geographic areas. Colonisation of new areas was achieved mostly by monomorphic lineages, whereas heterostylous species mostly remained in the ancestral Western Paleartic area.

The original version of this Data Descriptor contained an error in the author affiliations. Marwan Cheikh Albassatneh was incorrectly associated with Institute of Ecology and Environmental Sciences, Sorbonne University, Paris, France and Institut de Systématique, Evolution, Biodiversité (ISYEB), Muséum national d'Histoire naturelle (MNHN), CNRS, Sorbonne Université, EPHE, Université des Antilles, Paris, France was inadvertently omitted. This has now been corrected in both the PDF and HTML versions of the Data Descriptor.

Aim: The Mediterranean Basin is a major hotspot of plant biodiversity, including forest trees. Over the past centuries, Mediterranean forests have been fragmented and over-exploited, to which the threats of climate change are now added. Our aim is to better understand patterns and processes of tree biodiversity in the Mediterranean and to provide indicators complementing the traditional approaches to biodiversity conservation based on species counts and occurrences, using georeferenced phylogenetic diversity and endemism analyses in a spatial ecological context. Location: Mediterranean Europe. Methods: Using a dated phylogeny of the 64 Euro-Mediterranean tree genera, we calculated phylogenetic diversity for all 50 × 50 km2 grid cells spanning Mediterranean Europe (n = 643) and compared values with those obtained for genus-level taxonomic diversity. Then, we tested the relative influence of geography, past and present climate, and soil on tree diversity (phylogenetic or taxonomic) and its geographical turnover. Geographical patterns of phylogenetic endemism were inferred using the Categorical Analyses of Neo- and Paleo-Endemism (CANAPE) methodology. Results: We showed that phylogenetic and taxonomic diversity within and among cells are correlated and influenced by soil parameters as well as current, Holocene and Late Glacial Maximum climate. Southern Spain, Cyprus and some Aegean islands contained areas of disproportionately high phylogenetic diversity and a concentration of phylogenetic paleo-endemics, while phylogenetic neo-endemism was high in eastern Sicily. Mixed phylogenetic endemism regions were detected in southern Spain and Portugal, in the Balkans and in Crete. Main conclusions: Our phylogenetic approach provides relevant indicators for better protecting forests of the Mediterranean, encompassing past and present evolutionary processes and factors. We consider areas that show a concentration of evolutionary history manifested by high phylogenetic endemism a

Trees play a key role in the structure and function of many ecosystems worldwide. In the Mediterranean Basin, forests cover approximately 22% of the total land area hosting a large number of endemics (46 species). Despite its particularities and vulnerability, the biodiversity of Mediterranean trees is not well known at the taxonomic, spatial, functional, and genetic levels required for conservation applications. The WOODIV database fills this gap by providing reliable occurrences, four functional traits (plant height, seed mass, wood density, and specific leaf area), and sequences from three DNA-regions (rbcL, matK, and trnH-psbA), together with modelled occurrences and a phylogeny for all 210 Euro-Mediterranean tree species. We compiled, homogenized, and verified occurrence data from sparse datasets and collated them on an INSPIRE-compliant 10 × 10 km grid. We also gathered functional trait and genetic data, filling existing gaps where possible. The WOODIV database can benefit macroecological studies in the fields of conservation, biogeography, and community ecology.

The Mediterranean region is one of the most important worldwide hotspots in terms of number of species and endemism, and multiple hypotheses have been proposed to explain how diversification occurred in this area. The contribution of different traits to the diversification process has been evaluated in different groups of plants. In the case of Centaurium (Gentianaceae), a genus with a center of diversity placed in the Mediterranean region, polyploidy seems to have been an important driver of diversification as more than half of species are polyploids.

Aim: Understanding plant diversity and how different traits have shaped the current biodiversity setting across the world is one of the major challenges for evolutionary biology. In this sense, genus Linum have been broadly studied as a model of species showing heterostyly, but no studies have attempted to investigate possible correlations between heterostyly and diversification. Thus, in this study we aim to explore the origin and diversification of the genus Linum and to determine its centre of diversity and potential source for the colonisation of other areas. Also, we aim to study how heterostyly may have shaped diversification rates and colonisation patterns in the genus. Location: Worldwide (focused on the Western Palearctic). Taxon: Genus Linum L. (Linaceae). Methods: We analysed nuclear ITS and plastid ndhF, matK and trnL-F DNA regions in a total of 103 samples of 93 different species of the genus Linum, as well as seven samples from other Linaceae. We performed divergence time analysis in BEAST2 under a birth-death tree model, then used the resulting tree for an ancestral area reconstruction using the R package “BioGeoBEARS.” Finally, we estimated diversification rates using BAMM and examined the correlation between diversification rates and geographic ranges and heterostyly. Results: Linum s.l. diverged during the late Eocene to mid Oligocene (27.2–38.29 Ma at 95% highest posterior density interval) in the Western Palearctic, where most species diversified. Within-area speciation is the main mechanism of diversification in the genus. Most dispersal events occurred from the Western Palearctic to other regions, probably through long-distance dispersal (LDD). No changes were found regarding diversification rates in specific clades or in relation with reproductive system (heterostyly) or geographic areas. Colonisation of new areas was achieved mostly by monomorphic lineages, whereas heterostylous species mostly remained in the ancestral Western Paleartic area.

Background: Estimating outcrossing/selfing rates and characterizing genetic diversity with microsatellite markers are crucial to understanding the evolution of plant mating systems. Methods and results: We developed, optimized and characterized eight new primer pairs for Centaurium grandiflorum ssp. boissieri and transferred them to three subspecies of Centaurium quadrifolium. Two SSR loci were transferred from Sabatia campestris to the four Centaurium taxa. Polymorphisms, He, Ho and H–W deviations were estimated in two populations of C. grandiflorum ssp. boissieri and in seven individuals each of C. quadrifolium ssp. barrelieri, C. quadrifolium ssp. parviflorum and C. quadrifolium ssp. quadrifolium. A total of 80 individuals was used in these experiments. The number of polymorphic loci varied among species from one to ten. A total of 127 alleles was scored. The average number of alleles per locus was 12.7. He was higher than Ho in all sampled populations. Hardy–Weinberg equilibrium was found for some loci in different species. Conclusions: This is the first report of microsatellites successfully amplified in the whole Centaurium genus. They will be valuable for estimating mating system parameters and genetic diversity and exploring their relationships with the wide variation in flower morphology in the genus, especially anther-stigma separation.

The original version of this Data Descriptor contained an error in the author affiliations. Marwan Cheikh Albassatneh was incorrectly associated with Institute of Ecology and Environmental Sciences, Sorbonne University, Paris, France and Institut de Systématique, Evolution, Biodiversité (ISYEB), Muséum national d'Histoire naturelle (MNHN), CNRS, Sorbonne Université, EPHE, Université des Antilles, Paris, France was inadvertently omitted. This has now been corrected in both the PDF and HTML versions of the Data Descriptor.

Aim: The Mediterranean Basin is a major hotspot of plant biodiversity, including forest trees. Over the past centuries, Mediterranean forests have been fragmented and over-exploited, to which the threats of climate change are now added. Our aim is to better understand patterns and processes of tree biodiversity in the Mediterranean and to provide indicators complementing the traditional approaches to biodiversity conservation based on species counts and occurrences, using georeferenced phylogenetic diversity and endemism analyses in a spatial ecological context. Location: Mediterranean Europe. Methods: Using a dated phylogeny of the 64 Euro-Mediterranean tree genera, we calculated phylogenetic diversity for all 50 × 50 km2 grid cells spanning Mediterranean Europe (n = 643) and compared values with those obtained for genus-level taxonomic diversity. Then, we tested the relative influence of geography, past and present climate, and soil on tree diversity (phylogenetic or taxonomic) and its geographical turnover. Geographical patterns of phylogenetic endemism were inferred using the Categorical Analyses of Neo- and Paleo-Endemism (CANAPE) methodology. Results: We showed that phylogenetic and taxonomic diversity within and among cells are correlated and influenced by soil parameters as well as current, Holocene and Late Glacial Maximum climate. Southern Spain, Cyprus and some Aegean islands contained areas of disproportionately high phylogenetic diversity and a concentration of phylogenetic paleo-endemics, while phylogenetic neo-endemism was high in eastern Sicily. Mixed phylogenetic endemism regions were detected in southern Spain and Portugal, in the Balkans and in Crete. Main conclusions: Our phylogenetic approach provides relevant indicators for better protecting forests of the Mediterranean, encompassing past and present evolutionary processes and factors. We consider areas that show a concentration of evolutionary history manifested by high phylogenetic endemism a

Trees play a key role in the structure and function of many ecosystems worldwide. In the Mediterranean Basin, forests cover approximately 22% of the total land area hosting a large number of endemics (46 species). Despite its particularities and vulnerability, the biodiversity of Mediterranean trees is not well known at the taxonomic, spatial, functional, and genetic levels required for conservation applications. The WOODIV database fills this gap by providing reliable occurrences, four functional traits (plant height, seed mass, wood density, and specific leaf area), and sequences from three DNA-regions (rbcL, matK, and trnH-psbA), together with modelled occurrences and a phylogeny for all 210 Euro-Mediterranean tree species. We compiled, homogenized, and verified occurrence data from sparse datasets and collated them on an INSPIRE-compliant 10 × 10 km grid. We also gathered functional trait and genetic data, filling existing gaps where possible. The WOODIV database can benefit macroecological studies in the fields of conservation, biogeography, and community ecology.

Background: Estimating outcrossing/selfing rates and characterizing genetic diversity with microsatellite markers are crucial to understanding the evolution of plant mating systems. Methods and results: We developed, optimized and characterized eight new primer pairs for Centaurium grandiflorum ssp. boissieri and transferred them to three subspecies of Centaurium quadrifolium. Two SSR loci were transferred from Sabatia campestris to the four Centaurium taxa. Polymorphisms, He, Ho and H–W deviations were estimated in two populations of C. grandiflorum ssp. boissieri and in seven individuals each of C. quadrifolium ssp. barrelieri, C. quadrifolium ssp. parviflorum and C. quadrifolium ssp. quadrifolium. A total of 80 individuals was used in these experiments. The number of polymorphic loci varied among species from one to ten. A total of 127 alleles was scored. The average number of alleles per locus was 12.7. He was higher than Ho in all sampled populations. Hardy–Weinberg equilibrium was found for some loci in different species. Conclusions: This is the first report of microsatellites successfully amplified in the whole Centaurium genus. They will be valuable for estimating mating system parameters and genetic diversity and exploring their relationships with the wide variation in flower morphology in the genus, especially anther-stigma separation.

The original version of this Data Descriptor contained an error in the author affiliations. Marwan Cheikh Albassatneh was incorrectly associated with Institute of Ecology and Environmental Sciences, Sorbonne University, Paris, France and Institut de Systématique, Evolution, Biodiversité (ISYEB), Muséum national d'Histoire naturelle (MNHN), CNRS, Sorbonne Université, EPHE, Université des Antilles, Paris, France was inadvertently omitted. This has now been corrected in both the PDF and HTML versions of the Data Descriptor.

Aim: The Mediterranean Basin is a major hotspot of plant biodiversity, including forest trees. Over the past centuries, Mediterranean forests have been fragmented and over-exploited, to which the threats of climate change are now added. Our aim is to better understand patterns and processes of tree biodiversity in the Mediterranean and to provide indicators complementing the traditional approaches to biodiversity conservation based on species counts and occurrences, using georeferenced phylogenetic diversity and endemism analyses in a spatial ecological context. Location: Mediterranean Europe. Methods: Using a dated phylogeny of the 64 Euro-Mediterranean tree genera, we calculated phylogenetic diversity for all 50 × 50 km2 grid cells spanning Mediterranean Europe (n = 643) and compared values with those obtained for genus-level taxonomic diversity. Then, we tested the relative influence of geography, past and present climate, and soil on tree diversity (phylogenetic or taxonomic) and its geographical turnover. Geographical patterns of phylogenetic endemism were inferred using the Categorical Analyses of Neo- and Paleo-Endemism (CANAPE) methodology. Results: We showed that phylogenetic and taxonomic diversity within and among cells are correlated and influenced by soil parameters as well as current, Holocene and Late Glacial Maximum climate. Southern Spain, Cyprus and some Aegean islands contained areas of disproportionately high phylogenetic diversity and a concentration of phylogenetic paleo-endemics, while phylogenetic neo-endemism was high in eastern Sicily. Mixed phylogenetic endemism regions were detected in southern Spain and Portugal, in the Balkans and in Crete. Main conclusions: Our phylogenetic approach provides relevant indicators for better protecting forests of the Mediterranean, encompassing past and present evolutionary processes and factors. We consider areas that show a concentration of evolutionary history manifested by high phylogenetic endemism a

Trees play a key role in the structure and function of many ecosystems worldwide. In the Mediterranean Basin, forests cover approximately 22% of the total land area hosting a large number of endemics (46 species). Despite its particularities and vulnerability, the biodiversity of Mediterranean trees is not well known at the taxonomic, spatial, functional, and genetic levels required for conservation applications. The WOODIV database fills this gap by providing reliable occurrences, four functional traits (plant height, seed mass, wood density, and specific leaf area), and sequences from three DNA-regions (rbcL, matK, and trnH-psbA), together with modelled occurrences and a phylogeny for all 210 Euro-Mediterranean tree species. We compiled, homogenized, and verified occurrence data from sparse datasets and collated them on an INSPIRE-compliant 10 × 10 km grid. We also gathered functional trait and genetic data, filling existing gaps where possible. The WOODIV database can benefit macroecological studies in the fields of conservation, biogeography, and community ecology.

The Mediterranean region is one of the most important worldwide hotspots in terms of number of species and endemism, and multiple hypotheses have been proposed to explain how diversification occurred in this area. The contribution of different traits to the diversification process has been evaluated in different groups of plants. In the case of Centaurium (Gentianaceae), a genus with a center of diversity placed in the Mediterranean region, polyploidy seems to have been an important driver of diversification as more than half of species are polyploids.

Aim: Understanding plant diversity and how different traits have shaped the current biodiversity setting across the world is one of the major challenges for evolutionary biology. In this sense, genus Linum have been broadly studied as a model of species showing heterostyly, but no studies have attempted to investigate possible correlations between heterostyly and diversification. Thus, in this study we aim to explore the origin and diversification of the genus Linum and to determine its centre of diversity and potential source for the colonisation of other areas. Also, we aim to study how heterostyly may have shaped diversification rates and colonisation patterns in the genus. Location: Worldwide (focused on the Western Palearctic). Taxon: Genus Linum L. (Linaceae). Methods: We analysed nuclear ITS and plastid ndhF, matK and trnL-F DNA regions in a total of 103 samples of 93 different species of the genus Linum, as well as seven samples from other Linaceae. We performed divergence time analysis in BEAST2 under a birth-death tree model, then used the resulting tree for an ancestral area reconstruction using the R package “BioGeoBEARS.” Finally, we estimated diversification rates using BAMM and examined the correlation between diversification rates and geographic ranges and heterostyly. Results: Linum s.l. diverged during the late Eocene to mid Oligocene (27.2–38.29 Ma at 95% highest posterior density interval) in the Western Palearctic, where most species diversified. Within-area speciation is the main mechanism of diversification in the genus. Most dispersal events occurred from the Western Palearctic to other regions, probably through long-distance dispersal (LDD). No changes were found regarding diversification rates in specific clades or in relation with reproductive system (heterostyly) or geographic areas. Colonisation of new areas was achieved mostly by monomorphic lineages, whereas heterostylous species mostly remained in the ancestral Western Paleartic area.

The original version of this Data Descriptor contained an error in the author affiliations. Marwan Cheikh Albassatneh was incorrectly associated with Institute of Ecology and Environmental Sciences, Sorbonne University, Paris, France and Institut de Systématique, Evolution, Biodiversité (ISYEB), Muséum national d'Histoire naturelle (MNHN), CNRS, Sorbonne Université, EPHE, Université des Antilles, Paris, France was inadvertently omitted. This has now been corrected in both the PDF and HTML versions of the Data Descriptor.

Aim: The Mediterranean Basin is a major hotspot of plant biodiversity, including forest trees. Over the past centuries, Mediterranean forests have been fragmented and over-exploited, to which the threats of climate change are now added. Our aim is to better understand patterns and processes of tree biodiversity in the Mediterranean and to provide indicators complementing the traditional approaches to biodiversity conservation based on species counts and occurrences, using georeferenced phylogenetic diversity and endemism analyses in a spatial ecological context. Location: Mediterranean Europe. Methods: Using a dated phylogeny of the 64 Euro-Mediterranean tree genera, we calculated phylogenetic diversity for all 50 × 50 km2 grid cells spanning Mediterranean Europe (n = 643) and compared values with those obtained for genus-level taxonomic diversity. Then, we tested the relative influence of geography, past and present climate, and soil on tree diversity (phylogenetic or taxonomic) and its geographical turnover. Geographical patterns of phylogenetic endemism were inferred using the Categorical Analyses of Neo- and Paleo-Endemism (CANAPE) methodology. Results: We showed that phylogenetic and taxonomic diversity within and among cells are correlated and influenced by soil parameters as well as current, Holocene and Late Glacial Maximum climate. Southern Spain, Cyprus and some Aegean islands contained areas of disproportionately high phylogenetic diversity and a concentration of phylogenetic paleo-endemics, while phylogenetic neo-endemism was high in eastern Sicily. Mixed phylogenetic endemism regions were detected in southern Spain and Portugal, in the Balkans and in Crete. Main conclusions: Our phylogenetic approach provides relevant indicators for better protecting forests of the Mediterranean, encompassing past and present evolutionary processes and factors. We consider areas that show a concentration of evolutionary history manifested by high phylogenetic endemism a

Trees play a key role in the structure and function of many ecosystems worldwide. In the Mediterranean Basin, forests cover approximately 22% of the total land area hosting a large number of endemics (46 species). Despite its particularities and vulnerability, the biodiversity of Mediterranean trees is not well known at the taxonomic, spatial, functional, and genetic levels required for conservation applications. The WOODIV database fills this gap by providing reliable occurrences, four functional traits (plant height, seed mass, wood density, and specific leaf area), and sequences from three DNA-regions (rbcL, matK, and trnH-psbA), together with modelled occurrences and a phylogeny for all 210 Euro-Mediterranean tree species. We compiled, homogenized, and verified occurrence data from sparse datasets and collated them on an INSPIRE-compliant 10 × 10 km grid. We also gathered functional trait and genetic data, filling existing gaps where possible. The WOODIV database can benefit macroecological studies in the fields of conservation, biogeography, and community ecology.

The Mediterranean region is one of the most important worldwide hotspots in terms of number of species and endemism, and multiple hypotheses have been proposed to explain how diversification occurred in this area. The contribution of different traits to the diversification process has been evaluated in different groups of plants. In the case of Centaurium (Gentianaceae), a genus with a center of diversity placed in the Mediterranean region, polyploidy seems to have been an important driver of diversification as more than half of species are polyploids.

Aim: Understanding plant diversity and how different traits have shaped the current biodiversity setting across the world is one of the major challenges for evolutionary biology. In this sense, genus Linum have been broadly studied as a model of species showing heterostyly, but no studies have attempted to investigate possible correlations between heterostyly and diversification. Thus, in this study we aim to explore the origin and diversification of the genus Linum and to determine its centre of diversity and potential source for the colonisation of other areas. Also, we aim to study how heterostyly may have shaped diversification rates and colonisation patterns in the genus. Location: Worldwide (focused on the Western Palearctic). Taxon: Genus Linum L. (Linaceae). Methods: We analysed nuclear ITS and plastid ndhF, matK and trnL-F DNA regions in a total of 103 samples of 93 different species of the genus Linum, as well as seven samples from other Linaceae. We performed divergence time analysis in BEAST2 under a birth-death tree model, then used the resulting tree for an ancestral area reconstruction using the R package “BioGeoBEARS.” Finally, we estimated diversification rates using BAMM and examined the correlation between diversification rates and geographic ranges and heterostyly. Results: Linum s.l. diverged during the late Eocene to mid Oligocene (27.2–38.29 Ma at 95% highest posterior density interval) in the Western Palearctic, where most species diversified. Within-area speciation is the main mechanism of diversification in the genus. Most dispersal events occurred from the Western Palearctic to other regions, probably through long-distance dispersal (LDD). No changes were found regarding diversification rates in specific clades or in relation with reproductive system (heterostyly) or geographic areas. Colonisation of new areas was achieved mostly by monomorphic lineages, whereas heterostylous species mostly remained in the ancestral Western Paleartic area.

Background: Estimating outcrossing/selfing rates and characterizing genetic diversity with microsatellite markers are crucial to understanding the evolution of plant mating systems. Methods and results: We developed, optimized and characterized eight new primer pairs for Centaurium grandiflorum ssp. boissieri and transferred them to three subspecies of Centaurium quadrifolium. Two SSR loci were transferred from Sabatia campestris to the four Centaurium taxa. Polymorphisms, He, Ho and H–W deviations were estimated in two populations of C. grandiflorum ssp. boissieri and in seven individuals each of C. quadrifolium ssp. barrelieri, C. quadrifolium ssp. parviflorum and C. quadrifolium ssp. quadrifolium. A total of 80 individuals was used in these experiments. The number of polymorphic loci varied among species from one to ten. A total of 127 alleles was scored. The average number of alleles per locus was 12.7. He was higher than Ho in all sampled populations. Hardy–Weinberg equilibrium was found for some loci in different species. Conclusions: This is the first report of microsatellites successfully amplified in the whole Centaurium genus. They will be valuable for estimating mating system parameters and genetic diversity and exploring their relationships with the wide variation in flower morphology in the genus, especially anther-stigma separation.

The theory of evolution is one of the greatest scientific achievements in the intellectual history of humankind, yet it is still contentious within certain social groups. Despite being as robust and evidence-based as any other notable scientific theory, some people show a strong reluctance to accept it. In this study, we used the Measure of Acceptance of the Theory of Evolution (MATE) and Knowledge of Evolution Exam (KEE) questionnaires with university students from four academic degree programs (Chemistry, English, History, and Biology) of ten universities from Spain to measure, respectively, acceptance and knowledge of evolutionary theory among third-year undergraduate students (nMATE = 978; nKEE = 981). Results show that acceptance of evolution is relatively high (87.2%), whereas knowledge of the theory is moderate (5.4 out of 10) although there are differences across degrees (Biology>Chemistry>History>English), and even among various universities (ranging from 4.71 to 5.81). Statistical analysis reveals that knowledge of evolutionary theory among Biology students is partially explained by the relative weight of evolutionary themes within the curriculum, suggesting that an increase in the number of hours dedicated to this topic could have a direct influence on students’ knowledge of it. We also found that religion may have a significant—although relatively small—negative influence on evolutionary theory acceptance. The moderate knowledge of evolution in our undergraduate students, together with the potential problem of acceptance in certain groups, suggests the need for a revision of the evolutionary concepts in the teaching curricula of our students since primary school. © 2020 Gefaell et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.