Humans annihilate species so quickly that evolution can not keep up

With the consequences of human activities pushing the Earth into a
Sixth mass extinction, a team of biologists calculated that plant and animal species are destroyed so quickly that evolution can not keep up.

Human activities, including
pollution, deforestation, overpopulation, poaching, ocean warming and extreme weather events related to climate change – are expected to lead many mammals to extinction over the next five decades that nature will need 3 at 7 million years ago to restore the levels of biodiversity it was before modern humans evolved, according to an alarming new analysis published Monday in the Proceedings of the National Academy of Sciences.

The authors of the study, from Aarhus University in Denmark and the University of Gothenburg in Sweden, call for drastic conservation efforts.

"It is much easier to save biodiversity now than to make it evolve later," said lead author Matt Davis of Aarhus University.
Press release.

For this study, the researchers analyzed a vast database of mammals including existing species and species that lived in the recent past but have disappeared since the rise of Homo sapiens. They determined that for 130,000 years that humans roam the planet, we have erased 2.5 billion years of evolutionary development by pushing 300 million different species of mammals to extinction.

When some species die, much of its "phylogenetic diversity" also disappears. For example, as Davis explains to the Guardian, the loss of some species of shrews is not as devastating as the loss of elephants. Losing elephants is equivalent to "cutting a large branch of the tree of life … while losing a species of shrew would amount to cutting a small branch."

Davis further noted in the press release:

"Large mammals, or megafauna, such as giant sloths and saber-toothed tigers, which had died out about 10,000 years ago, were extremely evolutionary.As they had few close relatives, their extinctions have caused the cutting of whole branches of the Earth's evolving tree.There are hundreds of species of shrews, which allows them to resist a few extinctions.There were only four species of tigers with saber, they have all disappeared. "

Worryingly, some of today's most iconic megafaunes are facing increasing extinction rates, warns the press release. Black rhinos have a high risk of extinction in the next 50 years. Asian elephants have less than a 33% chance of lasting beyond this century.

"Even if we once lived in a world of giants: giant beavers, armadillos and giants, giant deer, etc., we are now living in a world increasingly poor in wild mammals.The few remaining giants, such as rhinos and elephants, may disappear very quickly, "said Jens-Christian Svenning of the University of Aarhus in a press release.

Therefore, priority must be given to the safeguarding of animals with a long evolutionary history, including the black rhinoceros, the red panda and the indri lemur.

"This highlights the species we should try to save and could help us prioritize conservation," Davis told The Guardian.