ABSTRACT
The time estimates are also dependent upon the assumption of equal rates of evolution along the chimpanzee and human lineages. The reanalysis shown in Figure 2a-using a smaller, 1,600 base portion of this PDHA1 region that was also sequenced in the orangutan-yields a phylogenetic tree that clearly shows unequal rates of evolution. Such rate disparity often indicates the influence of selection, which would then call into question most of the population genetic
parameters and conclusions drawn. It would therefore seem to be premature to draw conclusions from the PDHA1 data until additional human and chimpanzee sequences are collected and new analyses performed.
