Study: Mammoth extinction blamed on climate change, not human hunting

About 4,000 years ago, the last majestic mammoth roaming the earth disappeared. For decades, scientists believed that these elephants' giant ancestors became extinct due to ruthless hunting by humans. But DNA analysis of the animals' lairs revealed a different story.

Researchers now say the more likely culprit for the animal's extinction is rapid climate change, which ultimately wiped out the creatures' food supply. But as well as solving the mystery of the mammoth's disappearance, the findings could shed light on the fate of other species if our current climate crisis isn't brought under control.

Eske Willerslev, co-author of the paper, researcher at the University of Cambridge, and director of the Center for Geogenetics at the Lundbeck Foundation at the University of Copenhagen, added: "This is a clear historical lesson that shows how unstoppable climate change is. Prediction - Once something is lost, there is no going back. ”

These gentle creatures that fed on grass and flowers lived alongside the Neanderthals. While many encounters may be peaceful, these animals are a hot commodity when it comes to making fur coats, musical and art instruments, and hearty meals. This is because of their thick chocolate-colored fur, huge strong tusks, and huge size.

They weighed about 6 tons and were about 13 feet (4 meters) tall - as Wang points out, mammoths could grow as tall as a double-decker bus.

"Scientists have been debating the cause of the mammoth extinction for 100 years," Willerslev said. "Humans have been blamed because these animals survived for millions of years without climate change. were not killed, but when they lived with humans, they did not last long and we were blamed for hunting them down."

Prehistoric people are suspected of being responsible for the eventual demise of the woolly mammoth. A cause other than climate change makes a lot of sense. These animals somehow survived the Ice Age about 12,000 years ago, but the researchers of the new study decided to dig deeper.

Over the course of 10 years, Willerslev led a team that dissected DNA fragments collected from Arctic soil where mammoths were known to have grazed. The samples were collected over 20 years and analyzed using a method called DNA shotgun sequencing.

DNA shotgun sequencing is an indirect method that can establish genetic profiles without the need for humans or animals to be present at the site. Rather than gathering genetic information from bones or teeth, the method sequences DNA from urine or traces of discarded cells. Scientists have used this tool to track the movement of COVID-19 by creating DNA profiles from sewage residue.

Researchers studying ancient mammoths have found that populations of the giant animals - discovered using sequencing methods - were depleted at a rate consistent with the rapid pace of climate change at the time. Willerslev noted that this is because as the climate warmed, trees and wetland plants took over and replaced the mammoths' grassland habitat. "When the climate became wetter and the ice began to melt, it led to the formation of lakes, rivers and swamps. The ecosystem changed and the biomass of vegetation decreased and would not be able to sustain mammoth herds."

Wang also noted that prehistoric humans likely spent much of their time hunting animals that were much smaller and easier to capture than giant mammoths, suggesting that they may have had a greater impact on animal extinctions than intuitively assumed. Be small.

Another important aspect of this discovery, Wang said, is that "we were finally able to show that it's not just climate change that's the problem, but that its rate is the final nail in the coffin -- when the landscape They were unable to adapt quickly when the transition was dramatic and their food became scarce."

This speed is why researchers naturally draw parallels between what happened then and what seems to be happening now. Global temperatures like ours are rising rapidly, and many countries' previous goal of limiting temperature increases to 1.5 degrees Celsius is now considered virtually impossible by the United Nations' Intergovernmental Panel on Climate Change - unless drastic measures are taken immediately.

"This shows that when it comes to the effects of drastic changes in weather, nothing is guaranteed. Early humans would have seen the world changed beyond recognition. This could easily happen again and we cannot take it for granted that we We will even be around to witness it. The only thing we can predict with certainty is that the change will be dramatic," Willerslav said.