Variable molecular clocks in hominoids.
Generation time is an important determinant of a neutral molecular clock. There are several human-specific life history traits that led to a substantially longer generation time in humans than in other hominoids. Indeed, a long generation time is considered an important trait that distinguishes humans from their closest relatives. Therefore, humans may exhibit a significantly slower molecular clock as compared to other hominoids. To investigate this hypothesis, we performed a large-scale analysis of lineage-specific rates of single-nucleotide substitutions among hominoids. We found that humans indeed exhibit a significant slowdown of molecular evolution compared to chimpanzees and other hominoids. However, the amount of fixed differences between humans and chimpanzees appears extremely small, suggesting a very recent evolution of human-specific life history traits. Notably, chimpanzees also exhibit a slower rate of molecular evolution compared to gorillas and orangutans in the regions analyzed.
Elango
Navin
N
School of Biology, Georgia Institute of Technology, Atlanta, GA 30332, USA.
Thomas
James W
JW
Yi
Soojin V
SV
D000818:Animals; D005075:Biological Evolution; D019070:Cell Lineage; D021901:DNA, Intergenic; D019143:Evolution, Molecular; D016678:Genome; D015186:Hominidae / Q000235:genetics*; D006801:Humans; D007438:Introns; D007700:Kinetics; D008253:Macaca mulatta; D008957:Models, Genetic; D002679:Pan troglodytes; D010802:Phylogeny; D020641:Polymorphism, Single Nucleotide; D013997:Time Factors
D021901:DNA, Intergenic