We obtained the gene tree and estimated the time of the most recent common ancestor (T MRCA) for CD209, using the maximum-likelihood coalescent method implemented in GENETREE (Griffiths and Tavare 1994). The mutation rate μ for each gene was estimated on the basis of the net divergence between humans and chimpanzees and under the assumption both that the species separation occurred 5 million years ago (MYA) and of a generation time of 20 years. Using this μ and θ maximum likelihood (θML), we estimated the effective population size parameter (N e). With the assumption of a generation time of 20 years and the estimated N e, the coalescence time, scaled in 2Ne units, was converted into years. The coalescence process implemented in SIMCOAL2 (Laval and Excoffier 2004) allowed us to estimate the probability of the T MRCA for CD209, through 2×104 simulations, with use of both the number of observed segregating sites and the estimated N e .