ADELAIDE, Australia, March 5 (UPI) -- Australian researchers say DNA has helped understand the history of the now-extinct Falkland Islands wolf, the only land-based mammal on the isolated islands.
Previous theories have suggested the wolf somehow rafted on ice or vegetation, or crossed via a now-submerged land bridge or was even semi-domesticated and transported by early South American humans to the Falklands, 285 miles from the nearest land, Argentina.
Researchers from the University's Australian Center for Ancient DNA extracted tiny pieces of tissue from the skull of a specimen collected by Charles Darwin when he encountered the famously tame species in 1834.
Their findings suggested that the Falkland Islands wolf became isolated from its South American mainland relatives only about 16,000 years ago, around the peak of the last glacial period.
The absence of other mammals on the Falklands argued against any land bridge connection to the mainland, researches said.
"The Eureka moment was finding evidence of submarine terraces off the coast of Argentina," study leader Alan Cooper said. "They recorded the dramatically lowered sea levels during the Last Glacial Maximum [around 25,000-18,000 years ago]."
"At that time, there was a shallow and narrow [around 12 miles] strait between the islands and the mainland, allowing the Falkland Islands wolf to cross when the sea was frozen over, probably while pursuing marine prey like seals or penguins. Other small mammals like rats weren't able to cross the ice."