Falkland Islands Wolf Mystery Solved
Sarah C.P. Williams
“Getting that time frame gave us a big clue,” said Alan Cooper, director of the Australian Centre for Ancient DNA at the University of Adelaide, who led the new research. “We know that the sea was very low at that time because of all the icecaps.”
A 2009 study discovered that the closest living relative to the Falkland wolf is the South American maned wolf, which dispelled the theory that the wolves were descendants of domesticated dogs. But the study didn’t pin down the exact timeline for the Falkland Island wolves’ origin since they diverged from the maned wolves around seven million years ago. “The trouble was that these wolves were really very distantly related,” said Cooper.
So in the new work, rather than only looking at living species, Cooper’s team added data on an extinct fox, Dusicyon avus, which lived on mainland South America until about 3000 years ago. The researchers obtained seven samples of D. avus DNA and sequenced the mitochondrial genes COII and cytochrome b. Then the team constructed a phylogeny, fitting both D. avusand the Falkland Island wolf into the family tree. As a result, the lab found that the two species diverged around 16,000 years ago.
With that new timeline in hand, Cooper and his colleagues turned to the literature on the geology of the area. “We found studies showing terraces along the currently submerged coastline,” said Cooper. “And those terraces record where the shoreline was for a long period of time.”
Cooper found that during the ice age the oceans were 130 meters lower than their present levels, and the gap between present day Argentina and the Falkland Islands would have measured 20 to 30 kilometers across and only 10 to 30 meters deep. At times, it’s likely that the shallow water completely froze over. While rodents and herbivores would not have been able to cross the long expanses of ice, wolves could have survived by hunting seals, penguins, and other seabirds.
“I think we’ve nailed it now,” said Cooper. “We’re not planning on doing much more on this question at this point.”
- Austin JJ, Soubrier J, Prevosti FJ, Prates L, et al. The origins of the enigmatic Falkland Islands wolf (2013). Nature Communications 4, 1552.