The origin of the Falkland Islands wolf has been a mystery for centuries. Now extinct, the wolf is the only known land-based mammal native to the Islands, and scientists since Darwin have puzzled over when it became isolated from similar species and how it made its way across the water. Now, a study published in Nature Communications has shed more light on the puzzle, suggesting that the wolf crossed from what is now Argentina when a narrow strait between them froze over. That could have been as little as 16,000 years ago, far later than some previous estimates. The ice bridge theory has been floated before, but Popsci and others have detailed why this research bolsters the theory.