The horrible wolf was a distinct species, unlike the gray wolf, biologists discovered

The iconic, prehistoric horrible wolf, which roamed Los Angeles and elsewhere in the Americas more than 11 millennia ago, was a distinct species of the slightly smaller gray wolf, an international team of scientists reported in the journal today. Earth.

The study, which presents a mystery that biologists have been pondering for more than 100 years, was led by researchers from UCLA, together with colleagues from Durham University in the United Kingdom, Adelaide University in Australia and Ludwig Maximilian University in Germany.

“The fearsome troubled wolf, a legendary symbol of Los Angeles and the La Brea Tar Pits, has earned its place among the many large, unique species that became extinct at the end of the Pleistocene era,” said Robert Wayne of UCLA, a leading professor, said. of ecology and evolutionary biology and the co-author of the study. The Pleistocene, commonly called the Ice Age, ended about 11,700 years ago.

More than 4,000 cruel wolves have been excavated from the La Brea tar pits, but scientists still know little about their evolution or the reasons for their eventual disappearance. Gray wolves, which also occur in the fossil-rich pits, have survived to this day.

“Dirty wolves have always been an iconic representation of the last ice age in the Americas, but what we know about their evolutionary history is limited to what we can see from the size and shape of their bones,” said Angela, co-lead author. , said. Perri of Durham University.

These bones now reveal much more. Using leading molecular approaches to analyze five distressed wolf genomes from fossil bones from 13,000 to 50,000 years ago, the researchers were able to reconstruct the evolutionary history of the long-extinct carnivore for the first time.

Significantly, they found no evidence for the flow of genes between distressed wolves and North American gray wolves or coyotes. The absence of genetic transmission indicates that serious wolves evolved in isolation from the ancestors of the ice age of these other species.

“We found that the horrible wolf is not closely related to the gray wolf. Furthermore, we showed that the ominous wolf never interfered with the gray wolf,” says co-lead author Alice Mouton, who conducted the research as’ n postdoctoral fellowship UCLA. scholar in ecology and evolutionary biology in Wayne’s laboratory.

The ancestors of the gray wolf and the much smaller prairie variety evolved in Eurasia and are thought to have migrated to North America less than 1.37 million years ago, relatively recently in evolutionary time. In addition, it is now believed that the horrible wolf, based on the genetic difference of the species, originated in the Americas.

“When we first started this study, we thought horrible wolves were just associated gray wolves, so we were surprised to hear how extremely genetically different they were, so much so that they probably could not cross,” he said. said the latest study. author, Laurent Frantz, a professor at Ludwig Maximillian University and the British Queen Mary University. “It must mean that cruel wolves have long been isolated in North America to be so genetically distinct.”

“Terrible wolves are sometimes portrayed as mythical creatures – giant wolves scurrying around frozen landscapes – but the reality seems even more interesting,” said Kieren Mitchell of the University of Adelaide, a co-lead author.

The awful wolf was a ‘lone wolf’ when it comes to breeding

Breeding is very common among wolf lines as their geographical variations overlap. Modern gray wolves and coyotes, for example, cross regularly in North America. Yet the researchers, using a dataset that included a serious Pleistocene wolf, 22 modern North American gray wolves and coyotes and three ancient dogs, found that the distressed wolf did not interfere with any of the others – probably because it was genetically unable to reproduce with those species.

‘Our finding of no evidence of gene flow between distressed wolves and gray wolves or coyotes, despite the great overlap of the variety during the late Pleistocene, suggests that the common ancestor of gray wolves and prairie birds was probably in geographical isolation from members of the developed serious wolf offspring. , ‘Said Wayne. “This result is consistent with the hypothesis that distressed wolves originated in the Americas.”

Another hypothesis about the horrible wolf – one that has not been tested in the current study – relates to its extinction. It is widely believed that because of its body size – larger than gray wolves and coyotes – the distressed wolf was more specialized in hunting large prey and could not survive the extinction of its usual food sources. Mouton, now a postdoctoral researcher at the Belgian University of Liège, may have a lack of mutual breeding.

“Perhaps the ominous wolf’s inability to cross did not provide the necessary new traits that would allow them to survive,” she said.

Discover the mystery of the horrible wolf’s DNA

Although the ominous wolves followed up in this study had no progeny of gray wolves, coyotes or their recent ancestors in North America, a comparison of the DNA of serious wolves with that of gray wolves, coyotes and a wide variety of other wolf-like species revealed. general but far evolutionary relationship.

“The ancestors of distressed wolves probably deviated from those of gray wolves more than 5 million years ago – it was a great surprise to discover that this deviation occurred so early,” Mouton said. “This finding underscores how special and unique the troubled wolf was.”

Based on their genomic analyzes, the researchers also concluded that there are three primary descendants descended from the shared descent: horrible wolves, African foxes, and a group consisting of all other wolf-like species, including the gray wolf. .

Gray wolves, which today mostly live in the wilderness and remote regions of North America, are more closely related to African wild dogs and Ethiopian wolves than to distressed wolves, Wayne noted.

The study is the first ever to report genome-wide data on serious wolves.

The genomic analyzes – conducted in a joint effort at UCLA, Durham University, Oxford University, the University of Adelaide, Ludwig Maximilian University and Queen Mary University – focused on the abundant nuclear genome and mitochondrial genome. is in ancient remains. .

“The lower cost of sequencing analysis, in addition to the latest molecular biology methods for highly degraded materials, enables us to recover DNA from fossils,” Mouton said. “Genomic DNA genomic analyzes are an incredible tool to better understand the evolutionary history of ancient and extinct species.”