Abstract
A new method for detecting site-specific variation of evolutionary rate (the so-called covarion process) from protein sequence data is proposed. It involves comparing the maximum-likelihood estimates of the replacement rate of an amino acid site in distinct subtrees of a large tree. This approach allows detection of covarion at the gene or the amino acid levels. The method is applied to mammalian-mitochondrial-protein sequences. Significant covarion-like evolution is found in the (simian) primate lineage: some amino acid positions are fast-evolving (i.e. unconstrained) in non-primate mammals but slow-evolving (i.e. highly constrained) in primates, and some show the opposite pattern. Our results indicate that the mitochondrial genome of primates reached a new peak of the adaptive landscape through positive selection.
Original language | English |
---|---|
Pages (from-to) | 1313-1316 |
Number of pages | 4 |
Journal | Proceedings of the Royal Society B: Biological Sciences |
Volume | 269 |
Issue number | 1498 |
DOIs | |
State | Published - 7 Jul 2002 |
Externally published | Yes |
Keywords
- Covarion
- Maximum likelihood
- Mitochondrial genome
- Positive Darwinian selection
- Primates