Home https://server7.kproxy.com/servlet/redirect.srv/sruj/smyrwpoii/p2/ Science https://server7.kproxy.com/servlet/redirect.srv/sruj/smyrwpoii/p2/ The terrible wolves may have been lone survivors of an ancient line

The terrible wolves may have been lone survivors of an ancient line



The ancient, extinct horrible wolf may have been among the loneliest wolves – so genetically different from its closest wolf relative that it can no longer cross, forcing it into an evolutionary impasse when it disappeared 13,000 years ago.

This is the discovery based on a new study, an in-depth analysis of DNA extracted from ancient horrible wolf bones from North America. Once terrible wolves (The dog darkens) differ from gray wolves millions of years ago, they never seem to have mixed since.

In fact, their genetic lineage is so different from other canids that the research team suggests that the horrible wolves be placed entirely in a different genus – reclassified as Aenocyon dirus, as first proposed in 1

918.

“Sometimes wolves are depicted as mythical creatures – giant wolves that roam in gloomy frozen landscapes, but the reality is even more interesting,” said paleobiologist Kiren Mitchell of the University of Adelaide in Australia.

“Despite the anatomical similarities between gray wolves and horrible wolves – which suggests that they may be related in the same way as modern humans and Neanderthals – our genetic results show that these two species of wolves are much more like distant cousins. , like humans and chimpanzees. “

Remains of wolves can be found in fossils from 250,000 to about 13,000 years ago and appear to have dominated the carnivorous scene during the last ice age in present-day North America.

Only in the famous La Brea tar pits are the scary wolves dug slightly superior to the slightly smaller gray wolf (Canus lupus) more than a hundred times.

But the way they diverged, evolved, and eventually disappeared by the end of the Last Ice Age, about 11,700 years ago, was a challenge to reunite. So an international team of scientists set to work on one of the only clues we have: bones.

“Scary wolves have always been an iconic representation of the last ice age in America, but what we know about their evolutionary history is limited to what we can see by the size and shape of their bones,” said archaeologist Angela Perry of Durham University. .

But sometimes paleontological remains can contain other information inside: DNA preserved well enough to be sequenced. And this is being investigated by the team.

They obtained five DNA samples of a horrible wolf from more than 50,000 years ago to 12,900 years ago from Idaho, Ohio, Wyoming and Tennessee and sequenced them.

They were then compared with genomic data from eight canids living today, derived 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 gray fox (Urocyon cinereoargenteus).

They also generated new genomic sequences for the gray wolf, black-backed jackal (Canis mesomelas) and the side striped jackal (Canis).

They found that, unlike other wolves that migrate between regions, the horrible wolf stays in place, never straying from North America.

And, fascinatingly, although they have shared space with coyotes and gray wolves for at least 10,000 years, they never seem to have crossed paths with them to produce hybrids.

“When we first started this study, we thought horrible wolves were just amplified gray wolves, so we were surprised to learn how extremely genetically different they are, so much so that they probably couldn’t cross,” said the molecular geneticist. Laurent Franz from Ludwig Maximilian University in Germany and Queen Mary University in Great Britain.

“That must mean that horrible wolves have been isolated in North America for a very long time to become so genetically different.”

In fact, according to the team’s analysis, the horrible and gray wolves must have parted ways with a common ancestor more than 5 million years ago. When you think that dogs and wolves were different between 15,000 and 40,000 years, it’s really a very long time.

Crossbreeding between canid species whose territories overlap is quite common. The hybrid between a coyote and a wolf is so common that it has a name – koyulf – and dog-wolf hybrids are also not unknown (although their breeding as pets is extremely controversial in the United States). So for the horrible wolves that have spent so much time near canids without crossing, it is extremely unusual.

And although the team did not explore this possibility, genetic isolation could contribute to the eventual death of the ancient beast, as it was unable to adapt to the changing world with new traits.

“While ancient humans and Neanderthals appear to have crossed, as do modern gray wolves and coyotes, our genetic data provide no evidence that horrible wolves have crossed with living canine species,” Mitchell said. “All our data shows that the terrible wolf is the last surviving member of an ancient lineage different from all living canine teeth.”

The study was published in Nature.


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