Human activity threatens 50 billion years of evolution, say scientists

Our ‘human footprint’ is destroying more than 50 billion years of unique evolutionary history, warns a new study.

Research led by the Zoological Society of London and Imperial College found that many regions home to the greatest amount of unique evolutionary history are facing unprecedented levels of human pressure.

These include the Caribbean, the Western Ghats of India, and large parts of Southeast Asia.

The team mapped the evolutionary history of the world’s terrestrial vertebrates including amphibians, birds, mammals and reptiles.

They explored how areas with large concentrations of evolutionarily distinct and threatened species are being impacted by our ever-increasing ‘human footprint’.

Lead author Dr Rikki Gumbs, of Imperial College London, said: ‘Our analyses reveal the incomprehensible scale of the losses we face if we don’t work harder to save global biodiversity.

‘To put some of the numbers into perspective, reptiles alone stand to lose at least 13 billion years of unique evolutionary history, roughly the same number of years as have passed since the beginning of the entire universe.’

Using extinction risk data for around 25,000 species, the researchers also calculated the amount of evolutionary history – branches on the tree of life – currently threatened with extinction.

They found at least 50 billion years of evolutionary heritage is under threat, as well as a large number of species.

The greatest losses of evolutionary history will be driven by the extinction of entire groups of closely-related species that share long branches of the tree of life, such as pangolins and tapirs.

We could also lose highly evolutionarily distinct species that sit alone at the ends of extremely long branches, such as the ancient Chinese crocodile lizards, the Shoebill a gigantic bird that stalks the wetlands of Africa and the iconic Aye-aye, a nocturnal lemur with large yellow eyes and long spindly fingers.

This new study highlights priority species for conservation, based on their evolutionary uniqueness and the intense human pressure across the environments where they are thought to exist.

Many of these species are also a priority for ZSL’s EDGE of Existence programme, which works to conserve the world’s most evolutionarily distinct and threatened species from extinction – including the punk-haired Mary River turtle and the Purple frog.

Dr Gumbs said: ‘These are some of the most incredible and overlooked animals on Planet Earth.

‘From legless lizards and tiny blind snakes to pink worm-like amphibians called caecilians, we know precious little about these fascinating creatures, many of which may be sliding silently toward extinction.’

Co-author Dr James Rosindell, from Imperial College London, added: ‘Our findings highlight the importance of acting urgently to conserve these extraordinary species and the remaining habitat that they occupy – in the face of intense human pressures.’

The findings are published in Nature Communications.

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