The pythons invading Florida have been found to be Burmese-Indian hybrids, which means that they may be more adaptable than hoped. From ScienceDaily:
The study also found that at least a few of the snakes in the invasive South Florida population are not 100 percent Burmese pythons. Instead, the genetic evidence shows at least 13 snakes out of about 400 studied are a cross between two separate species: Burmese pythons, which mostly inhabit wetlands, and Indian pythons, which prefer higher ground. The interbreeding between Burmese and Indian pythons probably took place before the animals became established in the South Florida environment, and may have given them greater adaptability in their new habitats.
The South Florida pythons spring from a tangled family tree, with consequences for the species’ future spread that are hard to predict, the USGS scientists said.
“The snakes in South Florida are physically identifiable as Burmese pythons, but genetically, there seems to be a different, more complicated story,” said Margaret Hunter, a USGS research geneticist and lead author on the study published in the journal Ecology and Evolution.
Burmese pythons have been reproducing in the Everglades since the 1980s, and have caused important environmental changes including the decline of small-mammal populations in South Florida.
Sometimes interbreeding between related species “can lead to hybrid vigor, that is, the best traits of two species are passed onto their offspring,” Hunter said. “Hybrid vigor can potentially lead to a better ability to adapt to environmental stressors and changes. In an invasive population like the Burmese pythons in South Florida, this could result in a broader or more rapid distribution.”
In the wild, related species typically avoid interbreeding by using different habitats. In their native Asia, Burmese pythons prefer wet habitats, while Indian pythons tend to stick to drier ones. In previous studies, scientists have observed South Florida’s Burmese pythons in both wet and dry habitat types.
“Our ability to detect Burmese pythons in the Greater Everglades has been limited by their effective camouflage and secretive behavior,” said Kristen Hart, a USGS research ecologist and a co-author on the study. Paper. (open access) – Margaret E. Hunter, Nathan A. Johnson, Brian J. Smith, Michelle C. Davis, John S. S. Butterfield, Ray W. Snow, Kristen M. Hart. Cytonuclear discordance in the Florida Everglades invasive Burmese python (Python bivittatus) population reveals possible hybridization with the Indian python (P. molurus). Ecology and Evolution, 2018; DOI: 10.1002/ece3.4423 PDF More.
Readers who live in Florida should keep an eye on their cats and lapdog. Some pythons, we fear, will begin to prefer urban areas, rather like racoons and Canada geese do (cf Toronto). Pythons are sometimes found because missing cats have triggered a search…
The Biological Species Concept is not our friend.
See also: Claim: Hybridization “boosts evolution” in cichlids
Is the recently cited hybrid dolphin-whale a “new species”? No.
Monkey hybrids are monkeying with the biological species concept