Abstract
We sequenced a 1114-bp fragment of cytochrome b gene in six subspecies (115 samples) of Boa constrictor and detected 67 haplotypes. Our analyses revealed the presence of two distinct clades, one from Central America (CA) and the other covering the rest of South America (SA).
Sequence divergence between CA and SA clades is about 5-7%, which roughly corresponds to a separation at the time of uplift of the Colombian Andes following formation of the Panama Isthmus before 3.5 Myr Sequence divergence within the SA and CA clades is only 2-3%, suggesting a fairly recent spread of these clades into their current geographic ranges. Thus, we may not be dealing with taxa with a markedly old evolutionary history.
Because juveniles of B. constrictor feed mostly on small rodents, we hypothesized that spread of this species was allowed by a new food source represented by muroid rodents that appeared after closure of the Panama portal.