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Stochastic models of molecular evolution and the estimation of phylogeny and rates of nucleotide substitution in the hominoid primates
- Source :
- Journal of Human Evolution. 18:775-794
- Publication Year :
- 1989
- Publisher :
- Elsevier BV, 1989.
-
Abstract
- We have estimated phylogenetic patterns and rates of nucleotide substitution in the hominoid primates using two different probabilistic models of molecular evolution as applied to three different data sets of nucleic acid sequences. The orang-utan was found to be the out-group of the other hominoids examined. Within the African apes and human clade the sister-group relationship of chimpanzee and human was found to be statistically the best, although the magnitude of the error estimates (a reflection of random statistical fluctuations) makes this conclusion tentative. The ψν-globin data sets were found to be statistically the most consistent and gave estimates of the times of divergence of chimpanzee and human from gorilla and of chimpanzee from human as 7·7 ± 1·5 Ma (Millions of years ago) and 7·4 ± 1·5 Ma respectively, although the speculative nature of these estimates is emphasized. In all cases the calibration point was the assumed divergence of the orang-utan from the remaining hominoids at 14·5 Ma. There was no statistically significant evidence of a slowdown in nucleotide substitution rate for the human lineage, or among the hominoids as a whole with respect to the Old and New World monkeys. We advocate the continued use and development of stochastic models of molecular evolution as a basis for phylogenetic estimation. On this basis one can choose between competing hypotheses of relationship in a statistical manner and can provide estimates of the errors involved in such estimations. The assumptions of all stochastic models are open to test and future refinement.
Details
- ISSN :
- 00472484
- Volume :
- 18
- Database :
- OpenAIRE
- Journal :
- Journal of Human Evolution
- Accession number :
- edsair.doi...........3002effceadce25911bad149b0c2644d
- Full Text :
- https://doi.org/10.1016/0047-2484(89)90089-4