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Ecology and Evolutionary Biology

John E. McCormack

Species tree

Publication Year

Articles 1 - 2 of 2

Full-Text Articles in Life Sciences

Calibrating Divergence Times On Species Tree Versus Gene Trees: Implications For Speciation History Of Aphelocoma Jays, John Mccormack, Joseph Heled, Kathleen Delaney, A. Peterson, L. Knowles Dec 2010

Calibrating Divergence Times On Species Tree Versus Gene Trees: Implications For Speciation History Of Aphelocoma Jays, John Mccormack, Joseph Heled, Kathleen Delaney, A. Peterson, L. Knowles

John E. McCormack

Estimates of the timing of divergence are central to testing the underlying causes of speciation. Relaxed molecular clocks and fossil calibration have improved these estimates; however, these advances are implemented in the context of gene trees, which can overestimate divergence times. Here we couple recent innovations for dating speciation events with the analytical power of species trees, where multilocus data are considered in a coalescent context. Divergence times are estimated in the bird genus Aphelocoma to test whether speciation in these jays coincided with mountain uplift or glacial cycles. Gene trees and species trees show general agreement that diversification began …


Maximum Likelihood Estimates Of Species Trees: How Accuracy Of Phylogenetic Inference Depends Upon The Divergence History And Sampling Design, John Mccormack, Huateng Huang, L. Knowles Sep 2009

Maximum Likelihood Estimates Of Species Trees: How Accuracy Of Phylogenetic Inference Depends Upon The Divergence History And Sampling Design, John Mccormack, Huateng Huang, L. Knowles

John E. McCormack

The understanding that gene trees are often in discord with each other and with the species trees that contain them has led researchers to methods that incorporate the inherent stochasticity of genetic processes in the phylogenetic estimation procedure. Recently developed methods for species-tree estimation that not only consider the retention and sorting of ancestral polymorphism but also quantify the actual probabilities of incomplete lineage sorting are expected to provide an improvement over earlier summary-statistic based approaches that discard much of the information content of gene trees. However, these new methods have yet to be tested on truly challenging evolutionary histories …