We describe the pattern of molecular evolution at a sarcomeric myosin gene, MYH16, using more than 30,000 bp of exon and intron sequence data from the chimpanzee and human genome sequencing projects to evaluate the timing and consequences of a human lineage-specific frameshift deletion. We estimate the age of the deletion at approximately 5.3 MYA. This estimate is consistent with the time of human and chimpanzee divergence and is significantly older than the first appearance of the genus Homo in the fossil record. We also find conflicting estimates of nonsynonymous fixation rates (d(N)) across different regions of this gene, revealing a complex pattern inconsistent with a simple model of pseudogene evolution for human MYH16.