Population genetic structure and historical demography of the ground beetle Chlaenius costiger in the Tsinling-Dabashan Mountains of central China.

Population genetic structure and demographic history of the ground beetle Chlaenius costiger (Coleoptera: Carabidae) in the Tsinling-Dabashan Mountains of central China were estimated using mitochondrial DNA sequences (Cox1-tRNALeu-Cox2) of 144 individuals from 16 local populations. The high haplotype diversity was accompanied by low nucleotide diversity. Phylogenetic analysis (Bayesian inference) of the 43 haplotypes revealed no phylogeographic structure. Analysis of molecular variance suggested that most of the variation was attributed to within population variation (79.26%). Mantel test results showed a significant correlation between the genetic distance and geographical distance of the populations with a correlation coefficient equal to 0.216964 (P = 0.0471 < 0.05), indicating the presence of isolation by distance. Spatial AMOVA and PERMUT analyses showed no phylogeographic structure. Gene flow calculated through the number of migrants was high between many pairs of populations. The results of a neutrality test, mismatch distribution analyses, and Bayesian skyline plot analysis together showed a demographic expansion. The estimated expansion time of the whole sampled population was 0.125 million years. The complex topography in the Tsinling-Dabashan Mountains area led to the high level of genetic diversity, and migratory flight resulted in the high level of gene flow, leading to the lack of a phylogeographic structure.

Genetic diversity and historical demography of the narrow-range endemic Alpine toad, Scutiger liupanensis, in the Liupan Mountains of central China.

The genetic diversity and historical demography of the narrow-range endemic Alpine toad, Scutiger liupanensis, in the Liupanshan National Forest Park of central China were estimated using cytochrome b and cytochrome c oxidase subunit I (COI) from 85 individuals from five local populations. Both the haplotype diversity (Hd) and the nucleotide diversity (Pi) were very high. Phylogenetic analysis of the 63 haplotypes revealed two major clades, and an analysis of molecular variance attributed most of the variation to within populations. Mantel tests did not reveal an isolation by distance pattern of genetic divergence between populations, and SAMOVA showed no phylogeographic structure. The results of neutrality tests, mismatch distribution analyses, and allelic frequency spectra suggest that a sudden demographic expansion occurred, and that high genetic variation is beneficial to the survival and development of this species.