Simultaneous molecular dating of population and species divergences is essential in many biological investigations, including phylogeography, phylodynamics, and species delimitation studies. In these investigations, multiple sequence alignments consist of both intra- and inter-species samples (mixed samples). As a result, the phylogenetic trees contain inter-species, inter-population, and within-population divergences. Bayesian relaxed clock methods are often employed in these analyses, but they assume the same tree prior for both inter- and intra-species branching processes and require specification of a clock model for branch rates (independent vs. autocorrelated rates models). We evaluated the impact of a single tree prior onBayesian divergence time estimates by analyzing computer-simulated datasets. We also examined the effectof the assumption of independence of evolutionary rate variation among branches when the branch rates are autocorrelated. Bayesian approach with coalescent tree priors generally produced excellent molecular dates and highest posterior densities with high coverage probabilities. We also evaluated the performance of a non-Bayesian method, RelTime, which does not require the specification of a tree prior or a clock model. RelTime's performance was similar to that of the Bayesian approach, suggesting that it is also suitable to analyze datasets containing both populations and species variation when its computational-efficiency is needed.

These are simulated data and settings used to perform divergence time estimation in BEAST and RelTime.

The dataset consists of xml files used to perform BEAST2 (and StarBEAST2) analyses. For RelTime analyses, the file "reltime_ml_nucleotide.mao" was used as the configuration file to run RelTime in megacc (with the same alignments and tree topologies contained in the xml files).