The ancient terrible, extinct wolf was perhaps one of the most lonely wolves – so genetically distinct from its closest wolf parent that it could no longer reproduce, forcing it into an evolutionary stalemate when it died. 13,000 years ago.
It’s the discovery based on a new study, in-depth analysis of DNA extracted from ancient bones of terrible wolves from North America. Once the terrible wolves (The dog darkens) diverged from gray wolves millions of years ago, they seem never to have mingled since.
In fact, their genetic line is so different from other canids that the research team proposes that the terrible wolves be completely placed in another genus – that they be reclassified as Aenocyon dirus, as was first proposed in 1918.
“Fearsome wolves are sometimes described as mythical creatures – giant wolves prowling in icy, dark landscapes – but the reality turns out even more interesting,” said paleobiologist Kieren Mitchell of the University of Adelaide in Australia.
“Despite the anatomical similarities between gray wolves and terrible wolves – suggesting that they might perhaps be related in the same way as modern humans and Neanderthals – our genetic results show that these two wolf species look much more like distant cousins, like humans and chimpanzees. “
The dreaded wolf remains can be found in the fossil record from 250,000 to about 13,000 years ago and appear to have dominated the carnivore scene during the last Ice Age in what is now North America.
In the famous tar pits of La Brea alone, the excavated terrible wolves outnumber the slightly smaller gray wolves (Canis lupus) more than a hundredfold.
But how they diverged, evolved, and eventually disappeared towards the end of the last Ice Age, around 11,700 years ago, has been difficult to piece together. An international team of scientists therefore set to work on one of the only clues we have: bones.
“The dreaded wolves have always been an iconic representation of the last ice age of the Americas, but what we know of their evolutionary history has been limited to what we can see from the size and shape of their bones,” said archaeologist Angela Perri of Durham. University.
But sometimes paleontological remains can contain other information inside: DNA well enough preserved to be sequenced. And that’s what the team investigated.
They obtained five terrible wolf DNA samples from over 50,000 to 12,900 years ago, from Idaho, Ohio, Wyoming, and Tennessee, and sequenced them.
Then they compared them to genomic data from eight canids living today, obtained from a genomic database: gray wolf, coyote (Canis latrans), African wolf (Canis lupaster), dhole (Cuon alpinus), Ethiopian Wolf (Canis simensis), African wild dog (Lycaon pictus), Andean fox (Lycalopex culpaeus) and the gray fox (Urocyon cinereoargenteus).
They also generated new genomic sequences for the gray wolf, the black-backed jackal (Canis mesomelas) and the side-striped jackal (Canis).
They found that unlike other wolves that migrated between regions, the terrible wolf stayed put, never straying far from North America.
And, fascinatingly, even though they’ve shared space with coyotes and gray wolves for at least 10,000 years, they never seem to have interbreeded with them to produce hybrids.
“When we started this study, we thought that terrible wolves were just muscular gray wolves, so we were surprised to learn how extremely genetically different they were, so much so that they probably wouldn’t. could not cross, ”said molecular geneticist Laurent. Frantz from Ludwig Maximilian University in Germany and Queen Mary University in the UK.
“It must mean that terrible wolves have been isolated in North America for a very long time to become so genetically distinct.”
In fact, according to the team’s analysis, terrible wolves and gray wolves must have diverged from a common ancestor over 5 million years ago. When you consider that dogs and wolves diverged 15,000 to 40,000 years ago, that is indeed a very long time.
The crossing between species of canids whose territories overlap is quite common. The hybrid of a coyote and a wolf is so common that it has a name – coywolf – and wolf-dog hybrids are not unheard of either (although raising them as pets is extremely controversial in the States. -United). So, for terrible wolves, having spent so long near canines without spawning is very unusual.
And, although the team did not explore this possibility, genetic isolation could have contributed to the eventual demise of the ancient beast, as it was unable to adapt to an evolving world with new traits.
“While ancient humans and Neanderthals appear to have interbreeded, as gray wolves and modern coyotes do, our genetic data has provided no evidence that terrible wolves interbreed with living canine species,” said Mitchell. “All of our data indicates that the terrible wolf is the last surviving member of an ancient lineage distinct from all living dogs.”
The research was published in Nature.