Speciation is often categorized based on geographic modes (allopatric, parapatric or sympatric). Although it is widely accepted that species can arise in allopatry and then later become sympatrically or parapatrically distributed, patterns in the opposite direction are also theoretically possible (e.g.
View Article and Find Full Text PDFIguanian lizards form a diverse clade whose members have been the focus of many comparative studies of ecology, behavior, and evolution. Despite the importance of phylogeny to such studies, interrelationships among many iguanian clades remain uncertain. Within the Old World clade Acrodonta, Agamidae is sometimes found to be paraphyletic with respect to Chamaeleonidae, and recent molecular studies have produced conflicting results for many major clades.
View Article and Find Full Text PDFThe superfamily Colubroidea (> 2500 species) includes the majority of snake species and is one of the most conspicuous and well-known radiations of terrestrial vertebrates. However, many aspects of the phylogeny of the group remain contentious, and dozens of genera have yet to be included in molecular phylogenetic analyses. We present a new, large-scale, likelihood-based phylogeny for the colubroids, including 761 species sampled for up to five genes: cytochrome b (93% of 761 species sampled), ND4 (69%), ND2 (28%), c-mos (54%), and RAG-1 (13%), totaling up to 5814bp per species.
View Article and Find Full Text PDFMolecular data offer great potential to resolve the phylogeny of living taxa but can molecular data improve our understanding of relationships of fossil taxa? Simulations suggest that this is possible, but few empirical examples have demonstrated the ability of molecular data to change the placement of fossil taxa. We offer such an example here. We analyze the placement of snakes among squamate reptiles, combining published morphological data (363 characters) and new DNA sequence data (15,794 characters, 22 nuclear loci) for 45 living and 19 fossil taxa.
View Article and Find Full Text PDFThe treefrogs (Hylidae) make up one of the most species-rich families of amphibians. With 885 species currently described, they contain >13% of all amphibian species. In recent years, there has been considerable progress in resolving hylid phylogeny.
View Article and Find Full Text PDFPhrynosomatid lizards are among the most common and diverse groups of reptiles in western North America, Mexico, and Central America. Phrynosomatidae includes 136 species in 10 genera. Phrynosomatids are used as model systems in many research programs in evolution and ecology, and much of this research has been undertaken in a comparative phylogenetic framework.
View Article and Find Full Text PDFMany authors have claimed that short branches in the Tree of Life will be very difficult to resolve with strong support, even with the large multilocus data sets now made possible by genomic resources. Short branches may be especially problematic because the underlying gene trees are expected to have discordant phylogenetic histories when the time between branching events is very short. Although there are many examples of short branches that are difficult to resolve, surprisingly, no empirical studies have systematically examined the relationships between branch lengths, branch support, and congruence among genes.
View Article and Find Full Text PDFUsing phylogeny-based methods to identify evolutionary transitions has become an integral part of evolutionary biology. Here, we demonstrate the potential for these methods to give statistically well-supported but misleading inferences about character evolution. We also show how inferences of character evolution can be informed using GIS-based methods to reconstruct ancestral environmental regimes.
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