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A relative of the elephant, the woolly mammoth is certainly one of the most famous extinct creatures of all.
The huge mammal is about 4 meters long and weighs about six tons and is depicted with ultra-round tusks and a heavy woolly coat.
Now, a new genome study suggests that the first woolly mammoths may not have been as fluffy as history remembers them.
Woolly mammoths evolved woollier coats, larger fat deposits and smaller ears over the 700,000 years they roamed the Siberian steppes, the study reveals.
It follows the revelation that scientists have been growing mammoth meat in a lab to make a mammoth meatball – though they’re not going to taste it for safety reasons.
Woolly mammoths were elephant-like animals that evolved in the arctic peninsula of Eurasia about 600,000 years ago. The last mammoths became extinct about 4000 years ago, after the construction of the pyramids in Giza, Egypt
The new study was conducted by researchers from the Center for Paleogenetics, Stockholm University and the Swedish Museum of Natural History.
The experts compared the genomes of woolly mammoths to modern elephants, their closest living relative.
“We wanted to know what makes a mammoth a woolly mammoth,” says lead author David Díez-del-Molino of the Center for Paleogenetics.
‘Woolly mammoths have some very distinctive morphological features, such as their thick fur and small ears, which you naturally expect based on what frozen specimens look like.
“But there are also many other adaptations, such as fat metabolism and cold perception, that are not so obvious because they are at the molecular level.”
The woolly mammoth (Mammuthus primigenius) was one of the last in a series of mammoth species that existed before becoming extinct about 4,000 years ago.
Woolly mammoths coexisted with early humans, who hunted them for food and used their bones and tusks for making weapons and art.
However, the cause of their extinction is uncertain, with intense debate over the role of human hunting and severe climate change.
For the new study, the Swedish team compared the genomes of 23 Siberian woolly mammoths with 28 contemporary Asian and African elephant genomes.
The new study suggests the first woolly mammoths may not have been as fluffy as history remembers them (file photo)
The experts compared the genomes of woolly mammoths to modern elephants, their closest living relative. Pictured, study co-author Marianne Dehasque at work in the ancient DNA lab at the Center for Paleogenetics in Stockholm
Study co-author Love Dalén with the Yuka mammoth, whose genome was included in the study
A total of 22 of these woolly mammoths were relatively modern and lived within the past 100,000 years, but the 23rd BCextended to one of the oldest known woolly mammoths, Chukochya, who lived about 700,000 years ago.
“Including the genome of one of the earliest known woolly mammoths allowed us to distinguish between mutations that arose in earlier forms of Mammuthus and those that evolved over the last 700,000 years,” the team say in their paper.
“This analysis offers a tantalizing glimpse of specific genes that have been linked in other mammals to changes in ear size, pelage, skin, body size, fat storage and metabolism, as well as immunity.”
Researchers found that the 700,000-year-old Chukochya genome shared about 91.7 percent of the mutations that caused protein-coding changes in the more modern woolly mammoths.
This means that many of the woolly mammoth’s defining traits — thick fur, fat metabolism and cold-sensing abilities — were likely already in place when the woolly mammoth first diverged from its ancestor, the steppe mammoth.
The steppe mammoth was not a woolly mammoth, but another species that came before. It dates from about 1.8 million years ago.
However, these defining traits of the woolly mammoth evolved further and became more pronounced in Chukochya’s descendants.
Chukochya is a 700,000-year-old early representative of the woolly mammoth. Before that was the steppe mammoth, which was not a woolly mammoth, but a completely different species
“The very first woolly mammoths were not yet fully evolved,” said study co-author Love Dalén, a professor of evolutionary genomics at the Center for Paleogenetics.
“They may have had larger ears and their wool was different — perhaps less insulating and fuzzy compared to later woolly mammoths.”
The more modern woolly mammoths also had several immune mutations not seen in their Chukochya’s ancestor, which may have given them immunity to viruses.
Researchers also found that genes that adapt to woolly mammoths are linked to living in cold environments, such as fat metabolism and storage.
The image shows a reconstruction of the steppe mammoths that preceded the woolly mammoth
Some genes are shared by unrelated modern arctic mammals such as reindeer and polar bears.
Meanwhile, mutations in a gene called ABCC11 could imply that woolly mammoths had “dry earwax and reduced body odor,” the researchers say.
The team points out that the mammoths whose genomes were included in this study were all collected in Siberia.
In the future, however, the researchers hope to branch out and compare North American woolly mammoths, which could provide a broader picture.
The new study is published in the journal Current Biology.