Genomic Divergences between Humans and Other Hominoids and the Effective Population Size of the Common Ancestor of Humans and Chimpanzees

摘要: To study the genomic divergences among hominoids and to estimate effective population size of common ancestor humans chimpanzees, we selected 53 autosomal intergenic nonrepetitive DNA segments from human genome sequenced them in a human, chimpanzee, gorilla, an orangutan. The average sequence divergence was only 1.24% ± 0.07% for human-chimpanzee pair, 1.62% 0.08% human-gorilla 1.63% chimpanzee-gorilla pair. These estimates, which were confirmed by additional data GenBank, are substantially lower than previous ones, included repetitive sequences might have been based on less-accurate data. between orangutans humans, gorillas 3.08% 0.11%, 3.12% 3.09% respectively, also estimates. other regions estimated extensive GenBank literature, Alus showed highest divergence, followed order Y-linked noncoding regions, pseudogenes, X-linked synonymous sites, introns, nonsynonymous sites. neighbor-joining tree derived concatenated segments—24,234 bp length—supports Homo-Pan clade with 100% bootstrap value. However, when each segment is analyzed separately, 22 (∼42%) give that incongruent species tree, suggesting large (Ne) Homo Pan. Indeed, parsimony analysis 37 protein-coding genes leads Ne = 52,000 96,000. As this 5 9 times larger long-term (∼10,000) various genetic polymorphism data, lineage apparently had experienced reduction after its separation chimpanzee lineage. Our assumes molecular clock, fact supported used. Taking orangutan speciation date as 12 16 million years ago, obtain 4.6 6.2 8.4 gorilla date, branched off 1.6 2.2 earlier did divergence.