What started out as a straightforward genetic study of Florida’s invasive python population has turned up a surprising plot twist: a small number of crossbred Burmese and Indian pythons with the potential to become a kind of Everglades super snake.

For the study, published Sunday in the journal Ecology and Evolution, U.S. Geological Survey researchers examined the tail tissue of 400 snakes captured in South Florida, from the Big Cypress Swamp to the Everglades. While the vast majority appeared to be closely related Burmese pythons — imagine a family reunion packed with first and second cousins — 13 had genetic markers from Indian pythons, a subspecies that unlike the swamp-loving Burmese snake prefers high, dry ground.

The number is clearly small, but it raises the risk that over time some Everglades snakes could become better suited to a more varied landscape. Scientists call it hybrid vigor.