4.2 | Factors influencing the genetic structures and differentiation of Sinocyclocheilus populations in the central Yunnan Basin
We found that altitudinal distances showed a stronger correlation (r=0.492, p<0.01)(Fig. 4 ). In our analysis ofSinocyclocheilus population structure, individuals that were collected from more similar altitudes tended to be more closely related genetically. This suggested that altitudinal variation had a strong effect on the genetic variation among Sinocyclocheiluspopulations. The results of our correlation analysis between the differentiation times of Sinocyclocheilus and Fst indicated that the river capture event appeared to have no discernable effects on the distribution of Sinocyclocheilus populations in the Central Yunnan Basin. This finding contrasts studies of other freshwater fish taxa that have found river capture events to play a key role in shaping the distributions of genetic lineages (e.g., Poissant et al., 2005; Burridge et al., 2007). We contend that geographical isolation and the unique ecological preferences of Sinocyclocheilus fishes were key factors driving population differentiation.