Although some organisms have moved to higher elevations and latitudes in response to recent climate change, there is little consensus regarding the capacity of different species to track rapid climate change via range shifts. Understanding species' abilities to shift ranges has important implications for assessing extinction risk and predicting future community structure. At an expanding front, colonization rates are determined jointly by rates of reproduction and dispersal. In addition, establishment of viable populations requires that individuals find suitable resources in novel habitats. Thus, species with greater dispersal ability, reproductive rate and ecological generalization should be more likely to expand into new regions under climate change. Here, we assess current evidence for the relationship between leading-edge range shifts and species' traits. We found expected relationships for several datasets, including diet breadth in North American Passeriformes and egg-laying habitat in British Odonata. However, models generally had low explanatory power. Thus, even statistically and biologically meaningful relationships are unlikely to be of predictive utility for conservation and management. Trait-based range shift forecasts face several challenges, including quantifying relevant natural history variation across large numbers of species and coupling these data with extrinsic factors such as habitat fragmentation and availability.

Two major approaches address the need to predict species distributions in response to environmental changes. Correlative models estimate parameters phenomenologically by relating current distributions to environmental conditions. By contrast, mechanistic models incorporate explicit relationships between environmental conditions and organismal performance, estimated independently of current distributions. Mechanistic approaches include models that translate environmental conditions into biologically relevant metrics (e.g. potential duration of activity), models that capture environmental sensitivities of survivorship and fecundity, and models that use energetics to link environmental conditions and demography. We compared how two correlative and three mechanistic models predicted the ranges of two species: a skipper butterfly (Atalopedes campestris) and a fence lizard (Sceloporus undulatus). Correlative and mechanistic models performed similarly in predicting current distributions, but mechanistic models predicted larger range shifts in response to climate change. Although mechanistic models theoretically should provide more accurate distribution predictions, there is much potential for improving their flexibility and performance.

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Being able to efficiently and accurately delimit species is one of the most basic and important aspects of systematics because species are the fundamental unit of analysis in biogeography, ecology, and conservation. We present a rationale and approach for combining ecological niche modeling, spatially explicit analyses of environmental data, and phylogenetics in species delimitation, and we use our methodology in an empirical example focusing on Aneides flavipunctatus, the black salamander (Caudata: Plethodontidae), in California. We assess the relationships between genetic, environmental, and geographic distance among populations. We use 11 climatic variables and point locality data from public databases to create ecological niche models. The suitability of potential contact zones between parapatric lineages is also assessed using the data from ecological niche modeling. Phylogenetic analyses of portions of the mitochondrial genome reveal morphologically cryptic mitochondrial lineages in this species. In addition, we find that patterns of genetic divergence are strongly associated with divergence in the ecological niche. Our work demonstrates the ease and utility of using spatial analyses of environmental data and phylogenetics in species delimitation, especially for groups displaying fine-scaled endemism and cryptic species.

Comparative phylogeography has emerged as a means of understanding the spatial patterns of genetic divergence of codistributed species. However, researchers are often frustrated because of the lack of appropriate statistical tests to assess concordancy of multiple phylogeographic trees. We develop a method for testing congruence across multiple species and synthesizing the data into a regional supertree. Nine phylogeographic data sets of species with different life histories and ecologies were statistically compared using maximum agreement subtrees (MAST) and showed a high degree of concordancy. A supertree combining the different phylogeographic trees was then computed using matrix representation with parsimony, and the groups defined by this supertree were tested against climatic data to investigate a potential mechanism driving divergence. Our data suggest that species and genetic lineages in California are shaped by climatic regimes. The supertree method in combination with MAST represents a new approach to test congruence hypotheses and detect common geographic signals in comparative phylogeography.

Background: There is a negative relationship between education and religiosity and a positive relationship between education and acceptance of evolution, but how this manifests in college students who differ in degree of religiosity and prior educational experiences is unclear. We focused our study on the relative importance of education and religion on evolution understanding for college students at a large, public university in the Deep South. Methods: We used a structural equation model incorporating both acceptance and knowledge of evolution to evaluate the relative influence of religion and education on evolution understanding of 2,999 surveyed students. We further focused on acceptance of evolution and academic level, college major, high school experience, religion, and religiosity. We conducted pre and post course evaluations in three biology classes, and finally we tested the relationships between the quality of K-12 state science standards and states' religiosity and educational attainment. Results: We found that the degree of religiosity mattered significantly more than education when predicting students' understanding of evolution. When we focused on acceptance of evolution only, students taught evolution or neither evolution nor creationism in high school had significantly higher acceptance than those taught both evolution and creationism or just creationism. Science majors always outscored non-science majors, and not religious students significantly outperformed religious students. Highly religious students were more likely to reject evolution even though they understood that the scientific community accepted the theory of evolution. Overall, students in two of three biology classes increased their acceptance of evolution, but only those students that seldom/never attended religious services improved. K-12 state science standard grades were significantly and negatively correlated with measures of state religiosity and significantly and positively correlated with measures of state educational attainment.

Identifying congruence in the geographical position of lineage breaks and species range limits across multiple taxa is a focus of the field of comparative phylogeography. These regions are biogeographical hotspots for investigations into the processes driving divergence at multiple phylogenetic levels. We used spatially explicit statistical methods to identify these regions for amphibians across the United States. Significant clustering occurred in the Appalachian Mountains and in the general area of Alabama - a region underappreciated as an important amphibian hotspot. When the orders Caudata and Anura were examined separately, spatial clustering was still found in Alabama for both. However, in Caudata the Appalachians and California were also important, and for Anura, the Great Lakes region was highlighted. When species richness was statistically controlled, cluster hotspots shifted out of Alabama and the Appalachians and moved to broader swaths of the Great Lakes region, southwestern United States and California. The exact location of particular suture zones is probably a result of complex interactions between historical and ecological factors including physiography, climate and distance from glacial refugia. These contact zone and phylogeographical break hotspots are ideal arenas in which to test alternative speciation hypotheses and examine the extent of reproductive isolation using novel, integrative approaches combining modern methods in statistical phylogeography, ecological niche modelling and genomics.

During the colder climates of the Pleistocene, the ranges of high-elevation species in unglaciated areas may have expanded, leading to increased gene flow among previously isolated populations. The phylogeography of the pygmy salamander, Desmognathus wrighti, an endemic species restricted to the highest mountain peaks of the southern Appalachians, was examined to test the hypothesis that the range of D. wrighti expanded along with other codistributed taxa during the Pleistocene. Analyses of genetic variation at 14 allozymic loci and of the 12S rRNA gene in the mtDNA genome was conducted on individuals sampled from 14 population isolates throughout the range of D. wrighti. In contrast to the genetic patterns of many other high-elevation animals and plants, genetic distances derived from both molecular markers showed significant isolation by distance and genetic structuring of populations, suggesting long-term isolation of populations. Phylogeographical analyses revealed four genetically distinct population clusters that probably remained fragmented during the Pleistocene, although there was also evidence supporting recent gene flow among some population groups. Support for isolation by distance is rare among high-elevation species in unglaciated areas of North and Middle America, although not uncommon among Plethodontid Salamanders, and this pattern suggests that populations of D. wrighti did not expand entirely into suitable habitat during the Pleistocene. We propose that intrinsic barriers to dispersal, such as species interactions with other southern Appalachian plethodontid salamanders, persisted during the Pleistocene to maintain the fragmented distribution of D. wrighti and allow for significant genetic divergence of populations by restricting gene flow.