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Identification of mechanisms that promote variation in life-history traits is critical to understand the evolution of divergent reproductive strategies. Here we compiled a large life-history data set (674 lizard populations, representing 297 species from 263 sites globally) to test a number of hypotheses regarding the evolution of life-history traits in lizards. We found significant phylogenetic signal in most life-history traits, although phylogenetic signal was not particularly high. Climatic variables influenced the evolution of many traits, with clutch frequency being positively related to precipitation and clutches of tropical lizards being smaller than those of temperate species. This result supports the hypothesis that in tropical and less seasonal climates, many lizards tend to reproduce repeatedly throughout the season, producing smaller clutches during each reproductive episode. Our analysis also supported the hypothesis that viviparity has evolved in lizards as a response to cooler climates. Finally, we also found that variation in trait values explained by clade membership is unevenly distributed among lizard clades, with basal clades and a few younger clades showing the most variation. Our global analyses are largely consistent with life-history theory and previous results based on smaller and scattered data sets, suggesting that these patterns are remarkably consistent across geographic and taxonomic scales.

We describe a new species of Leptophis (parrot snake) from the Cerrado ecoregion of Brazil. The new species, L . mystacinus sp. nov., differs from all other congeners in the following unique character combination: two Spectrum Green (129) to Light Parrot Green (133) dorsolateral stripes separated by a Buff (5) vertebral stripe, usually continuous onto the tail; loreal scale absent; postocular stripe Jet Black (300), wide and long (up 11 scales long onto nuchal region); maxillary teeth 21–25; ventrals 158–173; subcaudals 141–164; black spots on head absent; supracephalic plates of head not edged with black pigment; adult color pattern lacking dark oblique bands; keels absent on first dorsal scale rows; hemipenis unilobed, noncapitate, with undivided sulcus spermaticus, and first row of hemipenial body with four spines. Phylogenetic analysis of 16S mtDNA sequences indicate the new species is the sister taxon of L. dibernardoi , a species occurring in the neighboring Caatinga ecoregion.

As many new evolutionary lineages are being discovered and formally named, sequencing topotypes when holotypes are not available becomes essential for taxonomy. This study uses a DNA-taxonomy approach to sequence new populations of the Ischnocnema verrucosa species complex (Brazilian Wart Frogs) from different locations, including, for the first time, individuals from the type localities. Phylogenetic analysis of the mitochondrial 16S gene recovered a monophyletic Ischnocnema verrucosa species series composed of three main clades. The most recent common ancestor was estimated to be 33.76 million years ago, and diversification within the three main clades occurred primarily during the Miocene. We delimited eight species-level lineages with high levels of sequence divergence (7% to 16%). Our study highlights the importance of DNA taxonomy and the necessity of protecting and sequencing topotypes in taxonomic studies. Our study also contributes to the conservation and understanding of the genus Ischnocnema and the biodiversity of the Brazilian Atlantic Forest region.

Based on concordant differences in morphology, male advertisement call, and 16S mtDNA barcode distance, we describe a new species of Proceratophrys from southern Amazonia, in the states of Mato Grosso and Pará, Brazil. The new species is most similar to P. concavitympanum and P. ararype but differs from these species by its proportionally larger eyes and features of the advertisement call. Additionally, genetic distance between the new species and its congeners is 3.0–10.4% based on a fragment of the 16S rRNA gene, which is greater than the threshold typically characterizing distinct species of anurans. Using an integrative approach (molecular, bioacoustics, and adult morphology), we were able to distinguish the new species from other congeneric species. The new species is known only from the type locality where it is threatened by illegal logging and gold mining as well as hydroelectric dams.

Aim: The aim was to examine the links between past biome stability, vegetation dynamics and biodiversity patterns. Location: South America. Time period: Last 30,000 years. Major taxa studied: Plants. Methods: We classified South America into major biomes according to their dominant plant functional groups (grasses, trees and shrubs) and ran a random forest (RF) classification with data on current climate. We then fitted the algorithm to predict biome distributions for every 1,000 years back to 21,000 yr BP and estimated biome stability by counting how many times a change in climate was predicted to shift a grid cell from one biome to another. We compared our model-based stability map with empirical estimates from selected pollen records covering the past 30 kyr in terms of vegetation shifts, changes in species composition and time-lag of vegetation responses. Results: We found a strong correlation between our habitat stability map and regional vegetation dynamics. Four scenarios emerged according to the way forest distribution shifted during a climate change. Each scenario related to specific regional features of biome stability and diversity, allowing us to formulate specific predictions on how taxonomic, genetic and functional components of biodiversity might be impacted by modern climate change. Main conclusions: Our validated map of biome stability provides important baseline information for studying the impacts of past climate on biodiversity in South America. By focusing exclusively on climatic changes of manifested relevance (i.e., those resulting in significant habitat changes), it provides a novel perspective that complements previous datasets and allows scientists to explore new questions and hypotheses at the local, regional and continental scales.

Rates of climatic niche evolution vary widely across the tree of life and are strongly associated with rates of diversification among clades. However, why the climatic niche evolves more rapidly in some clades than others remains unclear. Variation in life history traits often plays a key role in determining the environmental conditions under which species can survive, and therefore, could impact the rate at which lineages can expand in available climatic niche space. Here, we explore the relationships among life-history variation, climatic niche breadth, and rates of climatic niche evolution. We reconstruct a phylogeny for the genus Desmognathus, an adaptive radiation of salamanders distributed across eastern North America, based on nuclear and mitochondrial genes. Using this phylogeny, we estimate rates of climatic niche evolution for species with long, short, and no aquatic larval stage. Rates of climatic niche evolution are unrelated to the mean climatic niche breadth of species with different life histories. Instead, we find that the evolution of a short larval period promotes greater exploration of climatic space, leading to increased rates of climatic niche evolution across species having this trait. We propose that morphological and physiological differences associated with variation in larval stage length underlie the heterogeneous ability of lineages to explore climatic niche space. Rapid rates of climatic niche evolution among species with short larval periods were an important dimension of the clade’s adaptive radiation and likely contributed to the rapid rate of lineage accumulation following the evolution of an aquatic life history in this clade. Our results show how variation in a key life-history trait can constrain or promote divergence of the climatic niche, leading to variation in rates of climatic niche evolution among species.

AIM: The Interior Highlands (Ouachita Mountains and Ozark Plateau) are major physiographical regions of eastern North America and harbour many endemic species. Despite their close proximity, the Ozarks and Ouachitas have different geological histories and relatively distinct species pools. Few studies have tested the biogeographical origins of this region's fauna, and most researchers have treated the Interior Highlands as a single unit. Here, we inferred the sources and timing of colonization of the Ozarks and the Ouachitas by analysing the biogeography of three genera of plethodontid salamanders (Eurycea, Plethodon and Desmognathus). LOCATION: Eastern North America. METHODS: We constructed a well‐sampled, time‐calibrated phylogeny for the family Plethodontidae using three mitochondrial and three nuclear genes in beast. Genetic data were primarily taken from GenBank, although we also produced 76 novel sequences. Using lagrange, we reconstructed ancestral areas for North American plethodontids. We compared the frequency and timing of dispersal events between the Ozarks and Ouachitas to other putative sources such as the Eastern Highlands (Appalachian Mountains and associated limestone plateaus). RESULTS: We inferred nine dispersal events from the Eastern Highlands to the Interior Highlands, and just two dispersal events between the geographically proximate Ozarks and Ouachitas. Following one dispersal in the Oligocene, other inter‐highland dispersal events occurred in the Miocene and Pliocene, including two periods of near‐synchronous movements. MAIN CONCLUSIONS: Given the relatively limited faunal exchange between the Ozarks and Ouachitas, we conclude that either the river valley separating the Ozarks and Ouachitas is a more formidable barrier to plethodontid salamander dispersal than barriers separating the Interior Highlands from the Eastern Highlands, or ecological/community contingencies have limited dispersal within the Interior Highlands. In our study, geographical proximity of upland islands does not correspond with faunal similarity.

To investigate the influence of climate variables in shaping species distributions across a steep longitudinal environmental gradient. The state of Oklahoma, south-central United States. We used Geographical Information Systems (GIS) niche-based models to predict the geographic distributions of six pairs of closely related amphibian and reptile species across a steep longitudinal environmental gradient. We compared results from modelling with actual distributions to determine whether species distributions were primarily limited by environmental factors, and to assess the potential roles of competition and historical factors in influencing distributions. For all species pairs, GIS models predicted an overlap zone in which both species should occur, although in reality in some cases this area was occupied by only one of the species. We found that environmental factors clearly influence the distributions of most species pairs. We also found evidence suggesting that competition and evolutionary history play a role in determining the distributions of some species pairs. Niche-based GIS modelling is a useful tool for investigating species distribution patterns and the factors affecting them. Our results showed that environmental factors strongly influenced species distributions, and that competition and historical factors may also be involved in some cases. Furthermore, results suggested additional lines of research, such as ecological comparisons among populations occurring inside and outside predicted overlap zones, which may provide more direct insight into the roles of competitive interactions and historical factors in shaping species distributions.

The southeastern United States (U.S.) has experienced dynamic climatic changes over the past several million years that have impacted species distributions. In many cases, contiguous ranges were fragmented and a lack of gene flow between allopatric populations led to genetic divergence and speciation. The Southern Red-backed Salamander, Plethodon serratus, inhabits four widely disjunct regions of the southeastern U.S.: the southern Appalachian Mountains, the Ozark Plateau, the Ouachita Mountains, and the Southern Tertiary Uplands of central Louisiana. We integrated phylogenetic analysis of mitochondrial DNA sequences (1399 base pairs) with ecological niche modeling to test the hypothesis that climate fluctuations during the Pleistocene drove the isolation and divergence of disjunct populations of P. serratus. Appalachian, Ozark, and Louisiana populations each formed well-supported clades in our phylogeny. Ouachita Mountain populations sorted into two geographically distinct clades; one Ouachita clade was sister to the Louisiana clade whereas the other Ouachita clade grouped with the Appalachian and Ozark clades but relationships were unresolved. Plethodon serratus diverged from its sister taxon, P. sherando, ~5.4 million years ago (Ma), and lineage diversification within P. serratus occurred ~1.9–0.6 Ma (Pleistocene). Ecological niche models showed that the four geographic isolates of P. serratus are currently separated by unsuitable habitat, but the species was likely more continuously distributed during the colder climates of the Pleistocene. Our results support the hypothesis that climate-induced environmental changes during the Pleistocene played a dominant role in driving isolation and divergence of disjunct populations of P. serratus.

Associations between the morphology of animals and their ecology have contributed to our understanding of phenotypic diversity by helping to relate form and function. Most early studies on fishes used traditional measurements of linear distances on the body or fins to quantify morphological variation among taxa. More recently, geometric morphometric analyses have gained popularity for assessing phenotypic shape variation. Along with new methodologies for quantifying morphological variation, researchers have become increasingly aware of the influence of phylogeny on morphological and ecological traits. Our study, which spanned seven cyprinid genera, assessed the abilities of traditional and geometric morphometric approaches to characterize ecologically relevant morphological variation. Furthermore, we compared morphometric approaches employing two analyses (partial Mantel test and Phylogenetic Canonical Correlation Analysis (PCCA)) that test for correlations among data sets while explicitly accounting for phylogenetic relationships. Traditional morphology and body shape showed similar correlations with habitat use in all analyses. In contrast, only traditional morphology was correlated with diet; however, this was only revealed by the PCCA. Our findings indicated the taxonomic span of species under study and the statistical treatment of data are important factors to consider when choosing between traditional or geometric morphometric approaches. In addition, a better understanding of phylogenetic relationships will improve our ability to establish associations between morphology and ecology.