MEXICO:

MEXICO: The Central American river turtle really gets around—but not without some help. A genetic study of the critically endangered reptile surprised biologists, who were expecting to find a different lineage in each river basin. Instead, they found that seemingly separate populations had been mixing. The best explanation is that people have been transporting and trading the turtles for ages—up to 3,000 years. Ancient remains and sculptures of the turtles have been found hundreds of miles outside their natural range.