Anthropogenic climate change is rapidly altering local environments and threatening biodiversity throughout the world. Although many wildlife responses to this phenomenon appear largely ...idiosyncratic, a wealth of basic research on this topic is enabling the identification of general patterns across taxa. Here, we expand those efforts by investigating how avian responses to climate change are affected by the ability to cope with ecological variation through behavioural flexibility (as measured by relative brain size). After accounting for the effects of phylogenetic uncertainty and interspecific variation in adaptive potential, we confirm that although climate warming is generally correlated with major body size reductions in North American migrants, these responses are significantly weaker in species with larger relative brain sizes. Our findings suggest that cognition can play an important role in organismal responses to global change by actively buffering individuals from the environmental effects of warming temperatures.
Anthropogenic climate change is rapidly altering local environments and wildlife responses appear largely idiosyncratic. We investigated how avian phenotypic responses to climate change are affected by the ability to cope with ecological variation through behavioral flexibility (as measured by relative brain size). After accounting for the effects of phylogenetic uncertainty and across‐species variation in adaptive potential, we confirm that although warming temperatures drive major body size reductions in North American migrants, these reductions are significantly weaker in species with larger relative brain sizes.
Aim To understand the patterns of genetic, geographical and morphological diversification in the Arabian gecko subspecies Pristurus rupestris rupestris, and to discuss the various processes that ...generate and shape diversity in arid mountain ranges. Location Hajar Mountains, south-eastern Arabian Peninsula. Methods We sampled 466 individuals across the entire range of P. r. rupestris in the Hajar Mountains and sequenced one mitochondrial gene for all the samples, and one extra mitochondrial and four nuclear genes for a subset of 75 specimens. A total of 155 individuals were characterized morphologically. Multilocus coalescent-based methods were used for species delimitation, for phylogenetic inference of species trees and to investigate the diversification dynamics. Multivariate statistics were used to analyse morphological data. Results Our molecular methods revealed 14 candidate species hidden within the subspecies P. r. rupestris. Diversification started c. 15 Ma, but most of the lineages have evolved in the last 7 Ma of the mountains' orogeny, producing a mosaic of allopatric taxa. Secondary interchange has occurred between high and low elevation lineages, and along the mountain chain between unrelated lineages formerly separated by mountain blocks. Morphological variation between the 14 candidate species is slight, but a high elevation robust morphotype is identified. Main conclusions Our results support the notion that mountain ranges constitute important centres of diversification in arid regions, and also act as 'species pumps' into surrounding areas. We also demonstrate that arid mountains may constitute important reservoirs of cryptic diversity, even in common and widespread species. This, and previous evidence, suggest that the Hajar Mountains are a biological hotspot and an important reservoir of diversity. We therefore suggest that these mountains should be a priority focal point for conservation in Arabia.
Ecological stoichiometry and studies of biogeochemical niches have mainly focused on plankton and vascular plants, but the phenotypically closest modern relatives of early plants, bryophytes, have ...been largely neglected. We analysed C:N:P stoichiometries and elemental compositions (K, Na, Mg, Ca, S, Fe) of 35 widely distributed bryophyte species inhabiting springs. We estimated bryophyte C:N:P ratios and their biogeochemical niches, investigated how elementomes respond to the environment and determined whether they tend to diverge more for coexisting than non‐coexisting individuals and species. The median C:N:P was 145:8:1, intermediate between Redfield's ratio for marine plankton and those for vascular plants. Biogeochemical niches were differentiated amongst species and were phylogenetically conserved. Differences in individual and species‐specific elementomes increased with coexistence between species. Our results provide an evolutionary bridge between the ecological stoichiometries of algae and vascular plants and suggest that differences in elementomes could be used to understand community assemblages and functional diversity.
Our study provides, for the first time, an estimation of bryophyte C:N:P stoichiometry of 145:8:1, intermediate between Redfield's ratio for marine plankton and those for vascular plants. We found that biogeochemical niches were well differentiated amongst species and were considerably phylogenetically conserved, indicative of adaptive value for species. Our results provide an evolutionary bridge between the ecological stoichiometries of algae and vascular plants and suggest that differences in elementomes could be used to understand community assemblages and functional diversity.
Biological invasions pose one of the most severe environmental challenges of the twenty‐first century. A longstanding idea is that invasion risk is predictable based on the phylogenetic distance – ...and hence ecological resemblance – between non‐native and native species. However, current evidence is contradictory. To explain these mixed results, it has been proposed that the effect is scale‐dependent, with invasion inhibited by phylogenetic similarity at small spatial scales but enhanced at larger scales. Analyzing invasion outcomes in a global sample of bird communities, we find no evidence to support this hypothesis. Instead, our results suggest that invaders are locally more successful in the presence of closely related and ecologically similar species, at least in human‐altered environments where the majority of invasions have occurred. Functional trait analyses further confirm that the ecological niches of invaders are phylogenetically conserved, supporting the notion that successful invasion in the presence of close relatives is driven by shared adaptations to the types of niches available in novel environments.
Despite biological invasions being one of the main global environmental problems, there is still no theoretical or empirical agreement on whether a high phylogenetic relatedness between exotic and native species positively or negatively affects invasion success. We show that in birds invasion success generally increases with the presence of closely‐related species, but that predictive accuracy largely depends on considering the influence of human‐related disturbances in facilitating invasions.
Mosses are amongst the oldest and simplest plants, they can be found almost everywhere in the world, and they condition the structure and function of many ecosystems. Their sensitivity to ...environmental changes makes them very interesting subjects of study in ecology, and understanding them can provide insights into the evolutionary history of plants. However, the study of moss traits and their relationship with their environment is far behind that of vascular plants.
We sampled 303 assemblages of aquatic and semi‐aquatic (hygrophytic) mosses growing in semi‐natural springs distributed around the northeast of the Iberian Peninsula to study how moss traits vary depending on their evolutionary history, climate and water chemistry. To do so, we analysed 30 moss species and 17 traits using phylogenetic comparative methods and an extended RLQ analysis, accounting for spatial and phylogenetic information. We hypothesized that there is a sclerophylly continuum in mosses living across a gradient of high and low water conductivity springs that may mimic sclerophylly in vascular plants that live in stressful environments.
Results indicated that life‐forms and, especially, morphological traits were well preserved phylogenetically and responsive to water chemistry and climate. That combined with spatial autocorrelation in environmental variables resulted in a clustered distribution of phylogenetically closely related mosses in space. Mosses living in springs with a warm and dry climate that discharge hard water mainly presented species with needle‐like leaves, were denser, and had lower water absorption capacity. The opposite was found in cold, humid and soft water springs.
Synthesis. Our results suggest that climate and water chemistry are main determinants of traits of hygrophytic mosses and of species distributions. We found evidence of a potential sclerophylly continuum in moss traits, which we hypothesize may be mainly related to physical and physiological constraints produced by water chemistry. Our findings describe moss sclerophylly in a gradient of water conductivity similar to that found in vascular plants with water availability and temperature. Further experimental studies will be required to confirm the observations found in this study.
A free Plain Language Summary can be found within the Supporting Information of this article.
A free Plain Language Summary can be found within the Supporting Information of this article.
(Catalan ‐ Català)
Les molses són les plantes més simples i antigues. Gairebé arreu del món condicionen l'estructura i el funcionament dels ecosistemes. Llur sensibilitat als canvis ambientals fa que el seu estudi sigui d'especial rellevància en el camp de l'ecologia, aportant coneixements molt valuosos sobre la història evolutiva de les plantes. Tanmateix, l'estudi de les molses i les relacions d'aquestes amb l'ambient resta encara a les beceroles en comparació amb les plantes vasculars.
Es van mostrejar 303 comunitats de molses aquàtiques i semi‐aquàtiques (higrofítiques), que habitaven fonts semi‐naturals de Catalunya, per estudiar com els trets de les molses variaven segons la seva història evolutiva, el clima i la química de l'aigua de les fonts on es trobaven. Es van analitzar 30 espècies de molses i 17 trets fent servir mètodes filogenètics i un anàlisi RLQ, incorporant informació espacial i filogenètica. La nostra hipòtesi era que, en molses higrofítiques, existeix un gradient d'esclerofília que opera a través d'un gradient de conductivitat de l'aigua de les fonts, de forma similar al que trobem en les plantes vasculars que viuen en ambients estressants.
Els resultats indiquen que les formes de vida i els trets morfològics de les molses estan ben preservats filogenèticament i que varien seguint els gradients de conductivitat de l'aigua i del clima. Aquest fet combinat amb l'autocorrelació espacial en les variables ambientals, resulta en una distribució agregada en l'espai de les espècies més properes filogenèticament. Les molses que viuen en fonts de clima càlid i sec i de les quals brolla aigua d'alta conductivitat tendeixen a ser més denses, absorbir menys aigua i a tenir fil·lidis més allargassats. La tendència oposada es troba en fonts de clima fred, humit i amb aigua de baixa conductivitat.
Síntesi: Els nostres resultats suggereixen que el clima i la química de l'aigua determinen els trets de les molses higrofítiques i llurs distribucions. Hem trobat evidències d'un potencial gradient d'esclerofília en els trets de les molses que hipotetitzem que està relacionat amb els constrenyiments físics i fisiològics imposats per la química de l'aigua de les fonts. Seran necessaris treballs experimentals per a confirmar les observacions trobades en aquest estudi.
Understanding the genomic basis of adaptation to different abiotic environments is important in the context of climate change and resulting short‐term environmental fluctuations.
Using functional and ...comparative genomics approaches, we here investigated whether signatures of genomic adaptation to a set of environmental parameters are concentrated in specific subsets of genes and functions in lacertid lizards and other vertebrates.
We first identify 200 genes with signatures of positive diversifying selection from transcriptomes of 24 species of lacertid lizards and demonstrate their involvement in physiological and morphological adaptations to climate. To understand how functionally similar these genes are to previously predicted candidate functions for climate adaptation and to compare them with other vertebrate species, we then performed a meta‐analysis of 1,100 genes under selection obtained from ‐omics studies in vertebrate species adapted to different abiotic factors.
We found that the vertebrate gene set formed a tightly connected interactome, which was to 23% enriched in previously predicted functions of adaptation to climate, and to a large part (18%) involved in organismal stress response. We found a much higher degree of identical genes being repeatedly selected among different animal groups (43.6%), and of functional similarity and post‐translational modifications than expected by chance, and no clear functional division between genes used for ectotherm and endotherm physiological strategies. In total, 171 out of 200 genes of Lacertidae were part of this network.
These results highlight an important role of a comparatively small set of genes and their functions in environmental adaptation and narrow the set of candidate pathways and markers to be used in future research on adaptation and stress response related to climate change.
Adaptation to the abiotic environment is mediated through a relatively small network of genes across vertebrates that is functionally enriched, repeatedly selected across species and partially involved in the response to stress. This study may help to narrow down which genes are being used to respond to contemporary climate change.
The taxonomy of Procellariiformes, particularly petrels and shearwaters, is still unresolved. The Manx shearwater Puffinus puffinus is one of the best studied seabirds worldwide. Most of the ...information known on this seabird is focused on the northern core populations where the species is abundant. However, the species shows a high number of peripheral populations, which are extremely small and difficult to study in comparison to central populations. Using an integrative approach, we provided significant evidence of phenological, morphological, acoustic, plumage colour and genetic differentiation of the Canarian Manx shearwaters (the most southern population) from the northern breeding colonies, which is compatible with a long period of isolation. Birds from the Canary Islands breed around 2–3 months earlier, are smaller and lighter and show darker underwing plumage than those from northern populations. In addition, Canarian call features are different from the northern populations. Finally, genetic analyses of the mitochondrial control region indicate an incipient genetic differentiation of Canarian Manx shearwaters from the other breeding populations. The Canarian population holds a small number of breeding colonies and it is declining, so accurate taxonomic recognition critically affects conservation efforts. For all the aforementioned reasons, we propose to rank the Canarian breeding population as a new taxon by presenting the formal description of a new subspecies Puffinus puffinus canariensis ssp. nov.
Nutrient economy and plant nutrient concentrations have been suggested as important selective pressures of reproductive traits in vascular plants. However, evidence supporting that the reproduction ...of bryophytes and their reproductive traits have also been conditioned by nutrient availability is lacking.
We here analysed the nutrient (N, P, K, and Fe) concentration of 35 aquatic and semi‐aquatic bryophytes and the chemistry of the spring water in which they lived to determine whether bryophyte nutrient concentrations were correlated with the frequency of sexual reproduction, main reproductive mode (sexual vs. asexual), dioicy, and spore diameter, while controlling for climate and nutrient concentrations in the spring water.
Water nutrient concentrations, except for K, had a small but positive influence on bryophyte nutrient concentrations. P‐rich and K‐poor species produced sporophytes more often and were more likely to reproduce sexually and be monoicous. Spore diameter was smaller in P‐ and Fe‐rich mosses but larger in N‐rich mosses living in humid climates. P‐rich species thus produced more and smaller spores and were able to propagate more extensively.
Overall, our results suggest that nutrient economy, especially P economy, has played an important role in shaping the reproductive traits of bryophytes.
Biologists have long noted that endotherms tend to have larger bodies (Bergmann's rule) and shorter appendages (Allen's rule) in colder environments. Nevertheless, many taxonomic groups appear not to ...conform to these 'rules', and general explanations for these frequent exceptions are currently lacking. Here we note that by combining complementary changes in body and extremity size, lineages could theoretically respond to thermal gradients with smaller changes in either trait than those predicted by either Bergmann's or Allen's rule alone. To test this idea, we leverage geographic, ecological, phylogenetic, and morphological data on 6,974 non-migratory terrestrial bird species, and show that stronger family-wide changes in bill size over thermal gradients are correlated with more muted changes in body size. Additionally, we show that most bird families exhibit weak but appropriately directed changes in both traits, supporting the notion of complementarity in Bergmann's and Allen's rules. Finally, we show that the few families that exhibit significant gradients in either bill or body size, tend to be more speciose, widely distributed, or ecologically constrained. Our findings validate Bergmann's and Allen's logic and remind us that body and bill size are simply convenient proxies for their true quantity of interest: the surface-to-volume ratio.
The fossil record provides compelling examples of heterochrony at macroevolutionary scales such as the peramorphic giant antlers of the Irish elk. Heterochrony has also been invoked in the evolution ...of the distinctive cranial frill of ceratopsian dinosaurs such as Triceratops. Although ceratopsian frills vary in size, shape, and ornamentation, quantitative analyses that would allow for testing hypotheses of heterochrony are lacking. Here, we use geometric morphometrics to examine frill shape variation across ceratopsian diversity and within four species preserving growth series. We then test whether the frill constitutes an evolvable module both across and within species, and compare growth trajectories of taxa with ontogenetic growth series to identify heterochronic processes. Evolution of the ceratopsian frill consisted primarily of progressive expansion of its caudal and caudolateral margins, with morphospace occupation following taxonomic groups. Although taphonomic distortion represents a complicating factor, our data support modularity both across and within species. Peramorphosis played an important role in frill evolution, with acceleration operating early in neoceratopsian evolution followed by progenesis in later diverging cornosaurian ceratopsians. Peramorphic evolution of the ceratopsian frill may have been facilitated by the decoupling of this structure from the jaw musculature, an inference that predicts an expansion of morphospace occupation and higher evolutionary rates among ceratopsids as indeed borne out by our data. However, denser sampling of the meager record of early‐diverging taxa is required to test this further.
We find support for peramorphic evolution of the frill of ceratopsian dinosaurs, likely facilitated by the decoupling of this structure from jaw musculature.
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