It Will Take 3-5 million Years for New Mammals to Evolve and Replace Those Wiped Out by Humans

Wednesday, 17 October 2018 - 12:38PM
Earth
Wednesday, 17 October 2018 - 12:38PM
It Will Take 3-5 million Years for New Mammals to Evolve and Replace Those Wiped Out by Humans
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Whether or not we know it, humans have been in the extinction business for tens of thousands of years, whether wiping out woolly mammoths or Neanderthals. Now, however, a sobering new study from Aarhus University in Denmark claims that the mammal species humans will wipe out in the next 50 years will take 3-5 million years to be replaced by new species that have survived and evolved to fill the gap. Unfortunately for the planet, that's the best-case scenario.

In the worst-case scenario, mammal extinctions will continue to occur, essentially dooming endangered species like the Asian elephant (which has only a 33% chance of surviving to the year 2100) and the black rhino. Large mammals like these are a special case, and are particularly at risk of disappearing. According to Jens-Christian Svenning: "We now live in a world that is becoming increasingly impoverished of large wild mammalian species. The few remaining giants, such as rhinos and elephants, are in danger of being wiped out very rapidly."

And things don't look good for the rest of the endangered species list, either. According to the International Union for the Conservation of Nature, 99.9% of critically endangered species and over two-thirds of endangered species will succumb to extinction within the next century. A short-sighted person might shrug and say "Survival of the fittest," but human actions are rapidly creating a hostile environment where very few species will be able to survive (including humans themselves). According to a meta-study published in Naturethe loss of biodiversity brought about by extinctions could decrease plant growth by 5 to 10% on the lower end of the spectrum, or cause environmental impacts "comparable to those witnessed with increasing ultraviolet radiation and a warming climate" on the higher end.

Conservation efforts, meanwhile, can help species get off the endangered list: so far, gray whales, pandas,and snow leopards have been removed. We just need to make sure a lot more species stay off the list.
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