Scientists solve the 320-year-old mystery of how the Falklands wolf ended up on the island: It skated across a frozen sea chasing a penguin
- Experts were baffled by how the now extinct animal crossed the sea
- Mystery was first recorded in 1690 – and raised again by Charles Darwin
- Researchers analysed DNA from famously tame animal found by Darwin
PUBLISHED: 13:13 EST, 6 March 2013 | UPDATED: 13:25 EST, 6 March 2013
It is a mystery that has puzzled biologists – including Charles Darwin – for 320 years.
Biologists had been unable to work out how the Falklands wolf came to be the only land-based mammal on the isolated islands, which are 460km from the nearest land, Argentina.
Previous theories have suggested the wolf somehow rafted on ice or vegetation, crossed via a now-submerged land bridge or was even semi-domesticated and transported by early South American humans.
Illustration of ‘Dusicyon australis’, the Falklands wolf, from Zoology of the Voyage of H.M.S. Beagle. Researchers have now solved the mystery of how the wolf gor to the Flaklands – and say it skated across a frozen sea
THE FALKLANDS WOLF
The Falkland Islands wolf (Dusicyon australis), is also known as the warrah and occasionally as the Falkland Islands dog.
It was the only native land mammal of the Falkland Islands until it became extinct in 1876, making it the first known canid to have gone extinct in historical times.
The first recorded sighting was by Captain John Strong in 1690. He took one, but during the voyage back to Europe it became frightened by the firing of the ship’s cannon and jumped overboard.
When Charles Darwin visited the islands in 1833 he found the species present on both West and East Falkland, and tame, but numbers were dwindling and he predicted that the animal would join the dodo among the extinct within ‘a very few years.’
Islanders hunted it for its fur, and were also concerned it would attack sheep.
Now, University of Adelaide researchers have found the answer – and say the animals skated across a frozen sea, probably chasing a penguin or seal.
Researchers from the University’s Australian Centre for Ancient DNA (ACAD) extracted tiny pieces of tissue from the skull of a specimen collected personally by Darwin.
The 320-year-old mystery was first recorded by early British explorers in 1690 and raised again by Charles Darwin following his encounter with the famously tame species on his Beagle voyage in 1834.
The findings were published in Nature Communications today and concluded that, unlike earlier theories, the Falkland Islands wolf (Dusicyon australis) only became isolated about 16,000 years ago around the peak of the last glacial period.
‘The eureka moment was finding evidence of submarine terraces off the coast of Argentina,’ says study leader Professor Alan Cooper.
‘They recorded the dramatically lowered sea levels during the Last Glacial Maximum (around 25-18,000 years ago).’
‘At that time, there was a shallow and narrow (around 20km) 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.’
The team also used samples from a previously unknown specimen, which was recently re-discovered as a stuffed exhibit in the attic of Otago Museum in New Zealand.
The ‘submarine terraces’ that enabled the Falklands wolf to cross from Argentina during the Last Glacial Maximum (around 25-18,000 years ago). The image shows a shallow and narrow (around 20km) strait between the islands and the mainland
Wolf Crossed the Frozen Sea to Get to the Falklands
by Ann Gibbons on 5 March 2013, 11:50 AM
Lone wolf. The Falklands wolves first reached the remote islands by crossing a frozen land bridge during the last glacial maximum.
Credit: Michael Rothman for Ace Coinage
One of the oddest sights on Charles Darwin’s famous voyage of the Beagle must have been the Falkland Islands wolf, a remarkably tame animal the size of a Labrador retriever that roamed these specks of land 460 kilometers off the coast of Argentina. Differences in the size and color of wolves on different islands—and with wolves on the mainland—sparked Darwin’s thinking about the mutability of species. He was also perplexed by how these curious creatures got to the islands in the first place when no other mammals could be found there. “As far as I am aware,” he wrote in 1839, “there is no other instance in any part of the world, of so small a mass of broken land, distant from a continent, possessing so large a quadruped peculiar to itself.”
Now, researchers may finally have solved the mystery. By comparing ancient mitochondrial DNA (maternally inherited DNA from the powerhouses of the cell) from several species of extinct and living canids—the family that includes wolves, foxes, and dogs—an international team has found that the animals are most closely related to an extinct wolf from South America, and that the two split apart about 16,000 years ago, just after the end of the Last Glacial Maximum. This was a time when sea levels were dramatically lower and the wolves could have crossed the icy straits on foot, unknowingly taking the first steps toward becoming a new species, according to a report today in Nature Communications. “There was almost certainly a shallow and frozen strait between the islands and the mainland, allowing the Falklands wolf to cross when the sea was frozen over, probably while pursuing prey, like penguins or seals,” says molecular evolutionist Alan Cooper of the University of Adelaide in Australia, leader of the study.
Although humans drove the Falklands wolves to extinction soon after Darwin’s visit (an outcome he predicted, after seeing how unused to humans the animals were), the crew of the Beagle brought several specimens to England; the skeleton of one is still stored at the Natural History Museum in London, with Darwin’s handwriting on the label. A protective museum curator would not let Cooper drill a hole in the specimen’s tooth to remove DNA, but Cooper spotted a tiny sinus hole, about 1 millimeter wide in the skull. Using tiny tweezers, he extracted a “little chunk of dried nerve and blood vessels,” he says. An analysis of that DNA, as well as the mtDNA from five of the seven other known specimens of Falklands wolves, confirmed that it was a new species of canid, dubbed Dusicyon australis—and not a fox or a dog brought to the islands by humans, as some had thought.
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