Ancient DNA reveals secrets of Game of Thrones wolves

January 13, 2021

Extinct dire wolves split off from other wolves nearly six million years ago and were only a distant relative of today's wolves, according to new research published in Nature today (13 January).

Dire wolves, made famous in the TV show Game of Thrones, were common across North America until around 13,000 years ago, after which they went extinct.

The study shows that dire wolves were so different from other canine species like coyotes and grey wolves that they were not able to breed with each other. Previous analyses, based on morphology alone, had led scientists to believe that dire wolves were closely related to grey wolves.

The research was led by Durham University in the UK alongside scientists at the University of Oxford, Ludwig Maximilian University in Germany, the University of Adelaide in Australia and the University of California Los Angeles in the US.

For the first time, the international team has sequenced the ancient DNA of five dire wolf sub-fossils from Wyoming, Idaho, Ohio, and Tennessee, dating back to over 50,000 years ago. Their analyses showed that dire wolves and grey wolves were in fact very distant cousins. This is the first time ancient DNA has been taken from dire wolves revealing a complex history of these ice age predators. The collaboration of 49 researchers across nine countries analysed the genomes of dire wolves alongside those of many different wolf-like canid species. Their analyses suggest that unlike many canid species who apparently migrated repeatedly between North America and Eurasia over time, dire wolves evolved solely in North America for millions of years.

Although dire wolves overlapped with coyotes and grey wolves in North America for at least 10,000 years before their extinction, they found no evidence that they interbred with these species. The researchers suggest that their deep evolutionary differences meant that they were likely ill equipped to adapt to changing conditions at the end of the ice age.

Lead author, Dr Angela Perri from Durham University's Archaeology Department, said: "Dire wolves have always been an iconic representation of the last ice age in the Americas and now a pop culture icon thanks to Game of Thrones, but what we know about their evolutionary history has been limited to what we can see from the size and shape of their bones and teeth.

"With this first ancient DNA analysis of dire wolves we have revealed that the history of dire wolves we thought we knew - particularly a close relationship to grey wolves - is actually much more complicated than we previously thought.

"Instead of being closely related to other North American canids, like grey wolves and coyotes, we found that dire wolves represent a branch that split off from others millions of years ago, representing the last of a now extinct lineage."

Co-lead author, Dr Alice Mouton, from the University of California Los Angeles, added: "We have found the dire wolf is not closely related to the grey wolf. Further we show that the dire wolf never interbred with the grey wolf. In contrast, grey wolves, African wolves, dogs, coyotes and jackals can and do interbreed. Dire wolves likely diverged from grey wolves more than five million years ago, which was a great surprise that this divergence occurred so early. This finding highlights how special and unique the dire wolf was."

The dire wolf is one of the most famous prehistoric carnivores from Pleistocene America which became extinct around 13,000 years ago. Known scientifically as Canis dirus, meaning 'fearsome dog', they preyed on large mammals like bison. The team suggests the dire wolves' stark evolutionary divergence from grey wolves places them in an entirely different genus - Aenocyon dirus ('terrible wolf')- as first proposed by palaeontologist John Campbell Merriam over 100 years ago.

Co-lead author, Dr Kieren Mitchell, from the University of Adelaide, commented: "Dire wolves are sometimes portrayed as mythical creatures - giant wolves prowling bleak frozen landscapes - but reality turns out to be even more interesting.

"Despite anatomical similarities between grey wolves and dire wolves - suggesting that they could perhaps be related in the same way as modern humans and Neanderthals - our genetic results show these two species of wolf are much more like distant cousins, like humans and chimpanzees.

"While ancient humans and Neanderthals appear to have interbred, as do modern grey wolves and coyotes, our genetic data provided no evidence that dire wolves interbred with any living canine species. All our data point to the dire wolf being the last surviving member of an ancient lineage distinct from all living canines."

Senior author, Dr Laurent Frantz, from the Ludwig Maximilian University of Munich, added: "When we first started this study we thought that dire wolves were just beefed up grey wolves, so we were surprised to learn how extremely genetically different they were, so much so that they likely could not have interbred. Hybridisation across Canis species is thought to be very common, this must mean that dire wolves were isolated in North America for a very long time to become so genetically distinct."

Dire wolves became extinct around 13,000 years ago but thanks to fossil remains, DNA analysis and a little bit of help from Game of Thrones, their legend lives on.
-end-


Durham University

Related Ice Age Articles from Brightsurf:

Ice discharge in the North Pacific set off series of climate events during last ice age
Repeated catastrophic ice discharges from western North America into the North Pacific contributed to, and perhaps triggered, hemispheric-scale changes in the Earth's climate during the last ice age.

Ice Age manatees may have called Texas home
Manatees don't live year-round in Texas, but these gentle sea cows are known to occasionally visit, swimming in for a 'summer vacation' and returning to warmer waters for the winter.

Sea ice triggered the Little Ice Age, finds a new study
A new study finds a trigger for the Little Ice Age that cooled Europe from the 1300s through mid-1800s, and supports surprising model results suggesting that under the right conditions sudden climate changes can occur spontaneously, without external forcing.

How cold was the ice age? Researchers now know
A University of Arizona-led team has nailed down the temperature of the last ice age -- the Last Glacial Maximum of 20,000 years ago - to about 46 degrees Fahrenheit.

What causes an ice age to end?
Research by an international team helps to resolve some of the mystery of why ice ages end by establishing when they end.

New study results consistent with dog domestication during ice age
Analysis of Paleolithic-era teeth from a 28,500-year-old fossil site in the Czech Republic provides supporting evidence for two groups of canids -- one dog-like and the other wolf-like - with differing diets, which is consistent with the early domestication of dogs.

Did an extraterrestrial impact trigger the extinction of ice-age animals?
Based on research at White Pond near Elgin, South Carolina, University of South Carolina archaeologist Christopher Moore and 16 colleagues present new evidence of a controversial theory that suggests an extraterrestrial body crashing to Earth almost 13,000 years ago caused the extinction of many large animals and a probable population decline in early humans.

Dust in ice cores leads to new knowledge on the advancement of the ice before the ice age
Working with the ice core ReCap, drilled close to the coast in East Greenland, postdoc Marius Simonsen wondered why the dust particles from the interglacial period -- the warmer period of time between the ice ages -- were several times bigger than the dust particles from the ice age.

Ice-sheet variability during the last ice age from the perspective of marine sediment
By using marine sediment cores from Northwestern Australia, a Japanese team led by National Institute of Polar Research (NIPR) and the University of Tokyo revealed that the global ice sheet during the last ice age had changed in shorter time scale than previously thought.

What triggered the 100,000-year Ice Age cycle?
A slowing of ocean circulation in the waters surrounding Antarctica drastically altered the strength and more than doubled the length of global ice ages following the mid-Pleistocene transition, a new study finds.

Read More: Ice Age News and Ice Age Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.