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Accounting for rate variation among lineages in comparative demographic analyses

September 1, 2014

Genetic analyses of contemporary populations can be used to estimate the demographic histories of species within an ecological community. Comparison of these demographic histories can shed light on community responses to past climatic events. However, species experience different rates of molecular evolution, and this presents a major obstacle to comparative demographic analyses. We address this problem by using a Bayesian relaxed-clock method to estimate the relative evolutionary rates of 22 small mammal taxa distributed across northwestern North America. We found that estimates of the relative molecular substitution rate for each taxon were consistent across the range of sampling schemes that we compared. Using three different reference rates, we rescaled the relative rates so that they could be used to estimate absolute evolutionary timescales. Accounting for rate variation among taxa led to temporal shifts in our skyline-plot estimates of demographic history, highlighting both uniform and idiosyncratic evolutionary responses to directional climate trends for distinct ecological subsets of the small mammal community. Our approach can be used in evolutionary analyses of populations from multiple species, including comparative demographic studies.

Publication Year 2014
Title Accounting for rate variation among lineages in comparative demographic analyses
DOI 10.1111/evo.12469
Authors Andrew G. Hope, Simon Y. W. Ho, Jason L. Malaney, Joseph A. Cook, Sandra L. Talbot
Publication Type Article
Publication Subtype Journal Article
Series Title Evolution
Index ID 70147247
Record Source USGS Publications Warehouse
USGS Organization Alaska Science Center Biology WTEB