Evolutionary relationships of human populations on a global scale |
| |
Authors: | Nei M; Roychoudhury AK |
| |
Institution: | Institute of Molecular Evolutionary Genetics, Pennsylvania State University, University Park 16802-5303. |
| |
Abstract: | Using gene frequency data for 29 polymorphic loci (121 alleles), we
conducted a phylogenetic analysis of 26 representative populations from
around the world by using the neighbor-joining (NJ) method. We also
conducted a separate analysis of 15 populations by using data for 33
polymorphic loci. These analyses have shown that the first major split of
the phylogenetic tree separates Africans from non-Africans and that this
split occurs with a 100% bootstrap probability. The second split separates
Caucasian populations from all other non-African populations, and this
split is also supported by bootstrap tests. The third major split occurs
between Native American populations and the Greater Asians that include
East Asians (mongoloids), Pacific Islanders, and Australopapuans (native
Australians and Papua New Guineans), but Australopapuans are genetically
quite different from the rest of the Greater Asians. The second and third
levels of population splitting are quite different from those of the
phylogenetic tree obtained by Cavalli- Sforza et al. (1988), where
Caucasians, Northeast Asians, and Ameridians from the Northeurasian
supercluster and the rest of non- Africans form the Southeast Asian
supercluster. One of the major factors that caused the difference between
the two trees is that Cavalli-Sforza et al. used unweighted pair-group
method with arithmetic mean (UPGMA) in phylogenetic inference, whereas we
used the NJ method in which evolutionary rate is allowed to vary among
different populations. Bootstrap tests have shown that the UPGMA tree
receives poor statistical support whereas the NJ tree is well supported.
Implications that the phylogenetic tree obtained has on the current
controversy over the out-of-Africa and the multiregional theories of human
origins are discussed.
|
| |
Keywords: | |
本文献已被 Oxford 等数据库收录! |
|