New DNA Research Shows How Giant Woolly Mammoth Became Extinct

The woolly mammoth, a species of mammoth that existed at the Pleistocene geological epoch that lasted from about 2,580,000 to 11,700 years ago. The last of the line of mammoth species got extinct in the Helocene Epoch. The species roamed the earth and stopped existing.

There have been insinuations that the human activities then made them vanish from the surface of the earth 4,000 years ago but a new research has proven that to be false. 

The hairy creatures, dubbed as the cousins of the present day elephants existed alongside the early humans, with the oldest musical instrument, a flute being made from the bone of a mammoth. Apart from being part a regular staple of the human diet then, their skeletons were used to build shelters; their giant tusks were used to carve harpoons, with artworks of them featured on cave walls.

Geneticists wanting to know the actual reason the mammoths disappeared from the surface of the earth analysed ancient environmental Deoxyribonucleic Acid (DNA), and they were able to prove that it was the melting of the icebergs that led to the wipe-out. It was proven that when the icebergs melted, it became too wet for the animals to survive as their major food source, the vegetation became affected.

The research project that spanned for 10 years, led by Professor Eske Willerslev, a Fellow of St John’s College, University of Cambridge, and director of The Lundbeck Foundation GeoGenetics Centre, University of Copenhagen was published in journal, Nature on October 20, 2021.

The Willerslev-led team used DNA shotgun sequencing to scrutinize environmental plant and animal remains like urine, faeces and skin cells taken from soil samples that has been collected over a period of 20 years from the Artic sites that still has the remains of the mammoth creature. The use of the advanced new technology implies that geneticists and scientists will no longer have reliance on DNA samples from bones or teeth to gather enough genetic material to recreate a profile of ancient DNA.

A mammoth tusk on Logata River bank. Credit: Johanna Anjar

In the words of team leader, Professor Willerslev: “Scientists have argued for 100 years about why mammoths went extinct. Humans have been blamed because the animals had survived for millions of years without climate change killing them off before, but when they lived alongside humans they didn’t last long and we were accused of hunting them to death.

“We have finally been able to prove was that it was not just the climate changing that was the problem, but the speed of it that was the final nail in the coffin – they were not able to adapt quickly enough when the landscape dramatically transformed and their food became scarce.

“As the climate warmed up, trees and wetland plants took over and replaced the mammoth’s grassland habitats. And we should remember that there were a lot of animals around that were easier to hunt than a giant woolly mammoth – they could grow to the height of a double-decker bus!”

The mammoth lived on earth for about five million years with the magnificent large mammal evolving and weathering several Ice Ages. In the Ice Age, herds of mammoths, reindeer, and woolly rhinoceroses thrived in the cold and snowy conditions.

Even with the cold, vegetation then grew that kept the various animal species alive, with the vegetarian mammoths so big they needed huge stomachs to digest he various grasses, flowers, plant and small shrubs.

Modern Arctic landscape. Credit: Inger Greve Alsos

Fossil records has shown that mammoths lived on all continents with the exception of Australia and South America as they are known to travel long distances that would be equivalent  to going round the world twice in their lifetime. Research also discovered that mammoths populations initially survived the end of Ice Age in the coasts of Siberia and Alaska but it was discovered that they actually lived longer in other climes too, with the breeds of mammoth on the Wrangel Island and St Paul Island closely related even though there were largely geographically separated.

The research team as part of their project sequenced the DNA of 1,500 Arctic plants to allow them arrives at globally significant conclusions from the study.

The first author of the paper and Cambridge University Research Associate, Dr. Yucheng Wang had this to say about the project:

 “The most recent Ice Age – called the Pleistocene – ended 12,000 years ago when the glaciers began to melt and the roaming range of the herds of mammoths decreased. It was thought that mammoths began to go extinct then but we also found they actually survived beyond the Ice Age all in different regions of the Arctic and into the Holocene – the time that we are currently living in ­– far longer than scientists realized.

 “We zoomed into the intricate detail of the environmental DNA and mapped out the population spread of these mammals and show how it becomes smaller and smaller and their genetic diversity gets smaller and smaller too, which made it even harder for them to survive.

“When the climate got wetter and the ice began to melt it led to the formation of lakes, rivers, and marshes. The ecosystem changed and the biomass of the vegetation reduced and would not have been able to sustain the herds of mammoths. We have shown that climate change, specifically precipitation, directly drives the change in the vegetation – humans had no impact on them at all based on our models.”

 A selection of the sediment sampled from sites across the Arctic. Credit: Yucheng Wang

Woolly mammoths were able to co-exist with humans for nothing less than 2,000 years and their earth vanishing exodus can be termed as the last big naturally occurring extinction story.

Mammoth steppe. Credit: Guogang Zhang @Hubei University

Team leader, Professor Willerslev opined that there is a stark lesson from history showing how unpredictable climate change, affirming that once something is lost, it is hard to go back.

Continuing, he said:

“Precipitation was the cause of the extinction of woolly mammoths through the changes to plants. The change happened so quickly that they could not adapt and evolve to survive”.

“It shows nothing is guaranteed when it comes to the impact of dramatic changes in the weather. The early humans would have seen the world change beyond all recognition – that could easily happen again and we cannot take for granted that we will even be around to witness it. The only thing we can predict with any certainty is that the change will be massive.”

Reference: “Late Quaternary dynamics of Arctic biota from ancient environmental genomics” by Yucheng Wang, Mikkel Winther Pedersen, Inger Greve Alsos, Bianca De Sanctis, Fernando Racimo, Ana Prohaska, Eric Coissac, Hannah Lois Owens, Marie Kristine Føreid Merkel, Antonio Fernandez-Guerra, Alexandra Rouillard, Youri Lammers, Adriana Alberti, France Denoeud, Daniel Money, Anthony H. Ruter, Hugh McColl, Nicolaj Krog Larsen, Anna A. Cherezova, Mary E. Edwards, Grigory B. Fedorov, James Haile, Ludovic Orlando, Lasse Vinner, Thorfinn Sand Korneliussen, David W. Beilman, Anders A. Bjørk, Jialu Cao, Christoph Dockter, Julie Esdale, Galina Gusarova, Kristian K. Kjeldsen, Jan Mangerud, Jeffrey T. Rasic, Birgitte Skadhauge, John Inge Svendsen, Alexei Tikhonov, Patrick Wincker, Yingchun Xing, Yubin Zhang, Duane G. Froese, Carsten Rahbek, David Bravo Nogues, Philip B. Holden, Neil R. Edwards, Richard Durbin, David J. Meltzer, Kurt H. Kjær, Per Möller and Eske Willerslev, 20 October 2021, Nature.
DOI: 10.1038/s41586-021-04016-x