Chronology of deep nodes in the neotropical primate phylogeny: insights from mitochondrial genomes

Abstract

The evolution of Neotropical Primates (NP) is permeated by factors associated with the pattern of diversification and the biogeography of the major lineages. These questions can be better understood by providing a robust estimate of the chronological scenario of NP evolution, a reason why molecular dating methods have been widely applied. One aspect of especial interest is the timing of diversification of the major NP lineages (pitheciids, atelids and cebids), which may have resulted from rapid episodes of adaptive radiation, a question that requires NP divergence time estimates with accurate statistical certainty. In this study, we evaluated the primate timescale focused on the age of nodes of NP radiation. We investigated the performance of complete primate mitochondrial genomes as traditional molecular markers of primate evolution and further including original mitochondrial data from the endangered muriqui, Brachyteles arachnoides (Accession No. JX262672). Comparisons of the age estimates at NP nodes based on mitochondrial genomes with those obtained from a nuclear supermatrix showed similar degrees of uncertainty. Further molecular data and more informative calibration priors are required for a more precise understanding of the early NP diversification.

Figure 1. Bayesian phylogeny and timescale of primate evolution inferred from mitochondrial genomes.

Nodes were supported by 100% Bayesian posterior probability (PP) and 100% approximate likelihood ratio statistic (aLRT). Exceptions are illustrated by the values of PP/aLRT on nodes. Bars indicate 95% credibility intervals. (*) Node not recovered in ML analysis.

Figure 2. Plots of width of 95% Bayesian credibility intervals (CI, w) against inferred divergence times (t) with linear regression shown as dashed line.

All regressions were significant at p<0.01. (a) Mitochondrial genomes; (b) Neotropical primate data reported by Perelman et al ; Catarrhine data reported by Perelman et al .