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Aim: (1) To synthesize data on the physical and phylogeographical history of the Mexican highlands, with a focus on the Trans-Mexican Volcanic Belt (TMVB), and (2) to propose approaches and analyses needed for examining the interaction of climate and volcanism. Location: Mexico. Methods: We performed a literature and data survey of the climatic, geological and phylogeographical history of the Mexican highlands. We then assessed how the expected effects of topographic isolation, co-occurring palaeoclimatic fluctuations and volcanism can be tested against the distribution of genetic diversity of high-elevation taxa. Results: The Mexican highlands present a complex biogeographical, climatic and geological history. Montane taxa have been exposed to a sky-island dynamic through climate fluctuations, allowing for long-term in situ population persistence, while also promoting recent divergence and speciation events. Volcanic activity transformed part of the Mexican highlands during the Pleistocene, mainly in the TMVB, leading to co-occurring climate and topographical changes. The TMVB highlands provide a suitable template to examine how low-latitude mountains can facilitate both the long-term persistence of biodiversity as well as allopatric and parapatric speciation driven by climatic and geological events. Main conclusions: Climate fluctuations, together with recent volcanism, have driven the diversification and local persistence of biodiversity within the Mexican highlands. The climate-volcanism interaction is challenging to study; however, this can be overcome by coupling genomic data with landscape analyses that integrate the geological and climatic history of the region.

Aim Quantifying abundance distributions is critical for understanding both how communities assemble, and how community structure varies through time and space, yet estimating abundances requires considerable investment in fieldwork. Community‐level population genetic data potentially offer a powerful way to indirectly infer richness, abundance and the history of accumulation of biodiversity within a community. Here we introduce a joint model linking neutral community assembly and comparative phylogeography to generate both community‐level richness, abundance and genetic variation under a neutral model, capturing both equilibrium and non‐equilibrium dynamics. Location Global. Methods Our model combines a forward‐time individual‐based community assembly process with a rescaled backward‐time neutral coalescent model of multi‐taxa population genetics. We explore general dynamics of genetic and abundance‐based summary statistics and use approximate Bayesian computation (ABC) to estimate parameters underlying the model of island community assembly. Finally, we demonstrate two applications of the model using community‐scale mtDNA sequence data and densely sampled abundances of an arachnid community on La Réunion. First, we use genetic data alone to estimate a summary of the abundance distribution, ground‐truthing this against the observed abundances. Then, we jointly use the observed genetic data and abundances to estimate the proximity of the community to equilibrium. Results Simulation experiments of our ABC procedure demonstrate that coupling abundance with genetic data leads to improved accuracy and precision of model parameter estimates compared with using abundance‐only data. We further demonstrate reasonable precision and accuracy in estimating a metric underlying the shape of the abundance distribution, temporal progress towards local equilibrium and several key parameters of the community assembly process. For the insular arachnid assemblage, we find the joint distribution of genetic diversity and abundance approaches equilibrium expectations, and that the Shannon entropy of the observed abundances can be estimated using genetic data alone. Main conclusions The framework that we present unifies neutral community assembly and comparative phylogeography to characterize the community‐level distribution of both abundance and genetic variation through time, providing a resource that should greatly enhance understanding of both the processes structuring ecological communities and the associated aggregate demographic histories.

• Background and Aims It is widely accepted that hydraulic failure due to xylem embolism is a key factor contributing to drought-induced mortality in trees. In the present study, an attempt is made to disentangle phenotypic plasticity from genetic variation in hydraulic traits across the entire distribution area of a tree species to detect adaptation to local environments. • Methods A series of traits related to hydraulics (vulnerability to cavitation and hydraulic conductivity in branches), growth performance and leaf mass per area were assessed in eight Pinus canariensis populations growing in two common gardens under contrasting environments. In addition, the neutral genetic variability (F ST ) and the genetic differentiation of phenotypic variation (O ST ) were compared in order to identify the evolutionary forces acting on these traits. • Key Results The variability for hydraulic traits was largely due to phenotypic plasticity. Nevertheless, the vulnerability to cavitation displayed a significant genetic variability (approx. 5 % of the explained variation), and a significant genetic ÷ environment interaction (between 5 and 19 % of the explained variation). The strong correlation between vulnerability to cavitation and survival in the xeric common garden (r = -0.81; P < 0.05) suggests a role for the former in the adaptation to xeric environments. Populations from drier sites and higher temperature seasonality were less vulnerable to cavitation than those growing at mesic sites. No trade-off between xylem safety and efficiency was detected. Q ST of parameters of the vulnerability curve (0.365 for P₅₀ and the slope of the vulnerability curve and 0.452 for P₈₈) differed substantially from F ST (0.091), indicating divergent selection. In contrast, genetic drift alone was found to be sufficient to explain patterns of differentiation for xylem efficiency and growth. • Conclusions The ability of P. canariensis to inhabit a wide range of ecosystems seemed to be associated with high phenotypic plasticity and some degree of local adaptations of xylem and leaf traits. Resistance to cavitation conferred adaptive potential for this species to adapt successfully to xeric conditions.

Despite evidence that variation in male–female reproductive compatibility exists in many fertilization systems, identifying mechanisms of cryptic female choice at the gamete level has been a challenge. Here, under risks of genetic incompatibility through hybridization, we show how salmon and trout eggs promote fertilization by conspecific sperm. Using in vitro fertilization experiments that replicate the gametic microenvironment, we find complete interfertility between both species. However, if either species' ova were presented with equivalent numbers of both sperm types, conspecific sperm gained fertilization precedence. Surprisingly, the species' identity of the eggs did not explain this cryptic female choice, which instead was primarily controlled by conspecific ovarian fluid, a semiviscous, protein-rich solution that bathes the eggs and is released at spawning. Video analyses revealed that ovarian fluid doubled sperm motile life span and straightened swimming trajectory, behaviors allowing chemoattraction up a concentration gradient. To confirm chemoattraction, cell migration tests through membranes containing pores that approximated to the egg micropyle showed that conspecific ovarian fluid attracted many more spermatozoa through the membrane, compared with heterospecific fluid or water. These combined findings together identify how cryptic female choice can evolve at the gamete level and promote reproductive isolation, mediated by a specific chemoattractive influence of ovarian fluid on sperm swimming behavior.

Background The diversity and evolutionary success of beetles (Coleoptera) are proposed to be related to the diversity of plants on which they feed. Indeed, the largest beetle suborder, Polyphaga, mostly includes plant eaters among its approximately 315,000 species. In particular, plants defend themselves with a diversity of specialized toxic chemicals. These may impose selective pressures that drive genomic diversification and speciation in phytophagous beetles. However, evidence of changes in beetle gene repertoires driven by such interactions remains largely anecdotal and without explicit hypothesis testing. Results We explore the genomic consequences of beetle-plant trophic interactions by performing comparative gene family analyses across 18 species representative of the two most species-rich beetle suborders. We contrast the gene contents of species from the mostly plant-eating suborder Polyphaga with those of the mainly predatory Adephaga. We find gene repertoire evolution to be more dynamic, with significantly more adaptive lineage-specific expansions, in the more speciose Polyphaga. Testing the specific hypothesis of adaptation to plant feeding, we identify families of enzymes putatively involved in beetle-plant interactions that underwent adaptive expansions in Polyphaga. There is notable support for the selection hypothesis on large gene families for glutathione S-transferase and carboxylesterase detoxification enzymes. Conclusions Our explicit modeling of the evolution of gene repertoires across 18 species identifies putative adaptive lineage-specific gene family expansions that accompany the dietary shift towards plants in beetles. These genomic signatures support the popular hypothesis of a key role for interactions with plant chemical defenses, and for plant feeding in general, in driving beetle diversification.

AIM: We assessed the biogeographical implications of Pleistocene sea‐level fluctuations on the surface area of Macaronesian volcanic oceanic islands. We quantified the effects of sea‐level cycles on surface area over 1000‐year intervals. Using data from the Canarian archipelago, we tested whether changes in island configuration since the late Pleistocene explain species distribution patterns. LOCATION: Thirty‐one islands of four Macaronesian archipelagos (the Azores, Madeira, the Canary Islands and Cape Verde). METHODS: We present a model that quantifies the surface‐area change of volcanic islands driven by fluctuations in mean sea level (MSL). We assessed statistically whether Canarian islands that were merged during sea‐level lowstands exhibit a significantly higher percentage of shared (endemic) species than other comparable neighbouring islands that remained isolated, using multimodel comparisons evaluated using the Akaike information criterion (AIC). RESULTS: Each Macaronesian island exhibited a unique area‐change history. The previously connected islands of Lanzarote and Fuerteventura share significantly more species of Insecta than the similarly geographically proximate island pair of La Gomera and Tenerife, which have never been connected. Additionally, Lanzarote and Fuerteventura contain the highest percentage of two‐island endemic Plantae species compared with all other neighbouring island pairs within the Canaries. The multimodel comparison showed that past connectedness provides improved explanatory models of shared island endemics. MAIN CONCLUSIONS: Pleistocene sea‐level changes resulted in abrupt alterations in island surface areas, coastal habitats and geographical isolation, often within two millennia. The merging of currently isolated islands during marine lowstands may explain both shared species richness and patterns of endemism on volcanic islands. Currently, the islands are close to their long‐term minimum surface areas and most isolated configurations, suggesting that insular biota are particularly vulnerable to increasing human impact.

Competitive dietary and morphological divergence among co-occurring species are fundamental aspects of ecological communities, particularly on islands. Cabo Verde (~570 km west of continental Africa) hosts several endemic reptiles descended from common ancestors, with sympatric species exhibiting wide morphological variation and competing for limited resources. To explore the mechanisms of resource partitioning between coexisting species, DNA metabarcoding was used to compare the diets of large and small skinks, Chioninia vaillantii and Chioninia delalandii , in sympatric and allopatric contexts on Fogo Island and in a more competitive context on the small and resource-poor Cima Islet. The morphological variation of all populations was also examined to test the character displacement hypothesis and to compare the effect of different competitive scenarios. Results showed significant differences in diet and linear measurements between species and populations. The two sympatric populations of C. delalandii on Fogo and Cima showed similar changes in head morphology compared to the allopatric population, supporting character displacement. The effect of higher competitive pressure on Cima was evidenced by the increased morphological and dietary variation observed. This study demonstrates how sister species develop dietary adaptations/morphologies to maintain stable coexistence, especially in highly competitive scenarios, providing useful insights for effective conservation strategies.

Background The Iberian Peninsula is recognized as an important refugial area for species survival and diversification during the climatic cycles of the Quaternary. Recent phylogeographic studies have revealed Iberia as a complex of multiple refugia. However, most of these studies have focused either on species with narrow distributions within the region or species groups that, although widely distributed, generally have a genetic structure that relates to pre-Quaternary cladogenetic events. In this study we undertake a detailed phylogeographic analysis of the lizard species, Lacerta lepida , whose distribution encompasses the entire Iberian Peninsula. We attempt to identify refugial areas, recolonization routes, zones of secondary contact and date demographic events within this species. Results Results support the existence of 6 evolutionary lineages (phylogroups) with a strong association between genetic variation and geography, suggesting a history of allopatric divergence in different refugia. Diversification within phylogroups is concordant with the onset of the Pleistocene climatic oscillations. The southern regions of several phylogroups show a high incidence of ancestral alleles in contrast with high incidence of recently derived alleles in northern regions. All phylogroups show signs of recent demographic and spatial expansions. We have further identified several zones of secondary contact, with divergent mitochondrial haplotypes occurring in narrow zones of sympatry. Conclusions The concordant patterns of spatial and demographic expansions detected within phylogroups, together with the high incidence of ancestral haplotypes in southern regions of several phylogroups, suggests a pattern of contraction of populations into southern refugia during adverse climatic conditions from which subsequent northern expansions occurred. This study supports the emergent pattern of multiple refugia within Iberia but adds to it by identifying a pattern of refugia coincident with the southern distribution limits of individual evolutionary lineages. These areas are important in terms of long-term species persistence and therefore important areas for conservation.

The widespread phenomenon of polyandry (mating by females with multiple males) is an evolutionary puzzle, because females can sustain costs from promiscuity, whereas full fertility can be provided by a single male. Using the red flour beetle, Tribolium castaneum, we identify major fitness benefits of polyandry to females under inbreeding, when the risks of fertilization by incompatible male haplotypes are especially high. Fifteen generations after inbred populations had passed through genetic bottlenecks, we recorded increased levels of female promiscuity compared with noninbred controls, most likely due to selection from prospective fitness gains through polyandry. These data illustrate how this common mating pattern can evolve if population genetic bottlenecks increase the risks of fitness depression due to fertilization by sperm carrying genetically incompatible haplotypes.

Between-individual variance in potential reproductive rate theoretically creates a load in reproducing populations by driving sexual selection of male traits for winning competitions, and female traits for resisting the costs of multiple mating. Here, using replicated experimental evolution under divergent operational sex ratios (OSR, 9:1 or 1:6 ♀:♂) we empirically identified the parallel reproductive fitness consequences for females and males in the promiscuous flour beetle Tribolium castaneum. Our results revealed clear evidence that sexual conflict resides within the T. castaneum mating system. After 20 generations of selection, females from female-biased OSRs became vulnerable to multiple mating, and showed a steep decrease in reproductive fitness with an increasing number of control males. In contrast, females from male-biased OSRs showed no change in reproductive fitness, irrespective of male numbers. The divergence in reproductive output was not explained by variation in female mortality. Parallel assays revealed that males also responded to experimental evolution: individuals from male-biased OSRs obtained 27% greater reproductive success across 7-day competition for females with a control male rival, compared to males from the female-biased lines. Subsequent assays suggest that these differences were not due to postcopulatory sperm competitiveness, but to precopulatory/copulatory competitive male mating behavior.