Sunday, November 28, 2021

Dire Wolves Were Genetically Distinctive

Almost a year old, but this ancient DNA study is new to me. See also Twilight Beasts for more scholarly analysis, noting that: "To place this in context, jackals, coyotes, and gray wolves are more closely related to each other than to dire wolves."

[D]ire wolves lived in North America from about 250,000 to 13,000 years ago. They were about 20% bigger than today's gray wolves—the size of their skeletons often gives them away—and, like other wolves, they probably traveled in packs, hunting down bison, ancient horses, and perhaps even small mammoths and mastodons.
. . . 
Dire wolves would become Aenocyon dirus, a designation proposed in 1918, but that scientists largely disregarded. 
"The Aenocyon genus was left in the historical dust bin, but it can be resurrected," says Xiaoming Wang, a vertebrate paleontologist and expert on ancient canids at the Natural History Museum of Los Angeles County. "Based on the genetic data this team presents, I would support that reclassification."

Artists—and Game of Thrones creators—have often depicted the predators as large timber wolves: bulky, gray, and ferocious. But . . . living in the warmer latitudes of North America may have given them traits more common to canids and other animals in these climates, such as red fur, a bushy tail, and more rounded ears. As such . . . dire wolves may have resembled "a giant, reddish coyote."

Genetic analysis further revealed the predators probably evolved in the Americas, where they were the only wolflike species for hundreds of thousands—or perhaps millions—of years. When gray wolves and coyotes arrived from Eurasia, likely about 20,000 years ago, dire wolves were apparently unable to breed with them, as the researchers found no traces of genetic mixing.
Dire wolves are considered to be one of the most common and widespread large carnivores in Pleistocene America, yet relatively little is known about their evolution or extinction. Here, to reconstruct the evolutionary history of dire wolves, we sequenced five genomes from sub-fossil remains dating from 13,000 to more than 50,000 years ago. Our results indicate that although they were similar morphologically to the extant grey wolf, dire wolves were a highly divergent lineage that split from living canids around 5.7 million years ago. In contrast to numerous examples of hybridization across Canidae, there is no evidence for gene flow between dire wolves and either North American grey wolves or coyotes. This suggests that dire wolves evolved in isolation from the Pleistocene ancestors of these species. Our results also support an early New World origin of dire wolves, while the ancestors of grey wolves, coyotes and dholes evolved in Eurasia and colonized North America only relatively recently.
Angela R. Perri, et al.,"Dire wolves were the last of an ancient New World canid lineage" 591 Nature 87–91 (January 13, 2021).

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