Unusual p-distance value among rat snake group (Ptyas: Colubridae) in Sumatra and Java

摘要

The geological history of Sundaland gave rise to speciation as well as the genetic diversity within the islands of Sumatra and Java. Several previous studies have revealed the similarity of animals inhabiting Sundaland. Here, we examined the genetic relationship of the genus Ptyas from Sumatra and Java using the ND4 gene. Phylogenetic trees were constructed using parsimony, likelihood and Bayesian approaches. Uncorrected p-distance was also calculated to determine the genetic distance among the examined specimens. The average genetic distance between different species ranged from 11.4 to 17.0%. The distance for one species from different islands in Indonesia was considered low, which is only 0.1 to 1.9%. The phylogenetic tree showed two clades in the rat snake genus Ptyas; (1) clade P. korros, (2) clade P. carinata, P. mucosa and P. fuscus. The species P. carinata is a sister lineage to P. mucosa, while P. fuscus is a sister lineage to both. The low p-distance of genus Ptyas within species showed high genetic similarity. We suspect that trading activity plays a big role in the current genetic distribution.