The genetic diversity and the spatial structure of a species are likely consequences of both past and recent evolutionary processes,but relevant studies are still rare in East Asia where the Pleistocene climate has un...The genetic diversity and the spatial structure of a species are likely consequences of both past and recent evolutionary processes,but relevant studies are still rare in East Asia where the Pleistocene climate has unique influences.In this study,we examined the impact of past climate change and recent anthropogenic activities on the genetic structure and population size of the greater long-tailed hamster(Tscherskia triton),an agricultural rodent pest species in northern China.DNA sequence data of 2 mitochondrial genes and genotypic data of 11 microsatellite DNA loci from 41 populations(545 individuals)were gathered.Phylogenetic and population genetic analyses,as well as species distribution modeling and coalescent simulations,were conducted to infer its historical and demographic patterns and processes.Two deeply diverged mitochondrial clades were recovered.A small one was restricted to the Shandong Peninsula while the main clade was further divided into 3 geographic clusters by their microsatellite DNA genotypes:Northwest,North-center and Northeast.Divergence dating indicated a Middle-to-Late Pleistocene divergence between the 2 clades.Demographic analysis indicated that all 3 and pooled populations showed consistent long-period expansions during last glacial period;but not during the Holocene,probably due to the impact of climate warming and human disturbances.Conflicting patterns between mtDNA and microsatellite markers imply an anthropogenic impact on North-center populations due to intensified agricultural cultivation in this region.Our study demonstrated that the impact of past glaciation on organisms in East Asia significantly differs from that of Europe and North America,and human activity is an important factor in determining the genetic diversity of a species,as well as its spatial structure.展开更多
基金This research is supported by a grant from Knowledge Innovation Program of The Chinese Academy of Sciences(number KSCX3-EW-N-005)a grant from the National Basic Research Program(2007CB109101)of the Ministry of Science and Technology,China.We are grateful to Lifeng Zhu,Yibo Hu and Liling Huang for their technical advice on data analysis,to Alexei Drummond for his suggestions on Bayesian skyline plot analysis,to Fuwen Wei for valuable discussion and comments on this manuscriptand to Cam Hudson and Terry Boyd-Zhang for improving the English writing of this manuscript.
文摘The genetic diversity and the spatial structure of a species are likely consequences of both past and recent evolutionary processes,but relevant studies are still rare in East Asia where the Pleistocene climate has unique influences.In this study,we examined the impact of past climate change and recent anthropogenic activities on the genetic structure and population size of the greater long-tailed hamster(Tscherskia triton),an agricultural rodent pest species in northern China.DNA sequence data of 2 mitochondrial genes and genotypic data of 11 microsatellite DNA loci from 41 populations(545 individuals)were gathered.Phylogenetic and population genetic analyses,as well as species distribution modeling and coalescent simulations,were conducted to infer its historical and demographic patterns and processes.Two deeply diverged mitochondrial clades were recovered.A small one was restricted to the Shandong Peninsula while the main clade was further divided into 3 geographic clusters by their microsatellite DNA genotypes:Northwest,North-center and Northeast.Divergence dating indicated a Middle-to-Late Pleistocene divergence between the 2 clades.Demographic analysis indicated that all 3 and pooled populations showed consistent long-period expansions during last glacial period;but not during the Holocene,probably due to the impact of climate warming and human disturbances.Conflicting patterns between mtDNA and microsatellite markers imply an anthropogenic impact on North-center populations due to intensified agricultural cultivation in this region.Our study demonstrated that the impact of past glaciation on organisms in East Asia significantly differs from that of Europe and North America,and human activity is an important factor in determining the genetic diversity of a species,as well as its spatial structure.
