We Have Killed So Many Animals On Earth, It Will Take 7 Million Years To Bring All Of Them Back

Humans have been rampantly destroying the Earth's biosphere for decades, in our attempts to make a profit off it.

We've wiped out a number of different species over the years, to the point where we've actually messed with the planet's evolutionary cycle.

Reuters

According to a new study from the Aarhus University in Denmark, humans will continue to wipe out mammalian species for the next 50 years, so much so that Earth will need three to five million years to recover its evolutionary diversity.

They believe Earth might be entering its sixth mass extinction, which is a period of time in which the planet's environment will change so much that most plant and animal species will go extinct. The last event of this kind was the Cretaceous-tertiary extinction event, approximately 65.5 million years ago. This is what wiped out the dinosaurs, and half of all plant and animal life with it. To survive such an event, the species need to diversify with millions of years of evolution so at least some will have a chance of surviving and adapting to the new environment.

Reuters

But of course, evolution stops when there aren't any of a species to evolve. According to the International Union for the Conservation of Nature, 99.9 percent of critically endangered species and 67 percent of endangered species will be die out within the next 100 years. That's thanks to us carrying out deforestation, polluting the atmosphere and increasing global warming, overfishing waters, and much more.

Matt Davis, a paleontologist at Aarhus University leading the study, explained the concept by citing the example of the shrew. There are hundreds of species of the animal, so an extinction event today would likely leave a number of species alive. However, there were only four species of sabre-toothed tigers on the planet alongside the dinosaurs, so they all ended up going extinct, taking millions of years of evolution with them. That's why conservationists today are terrified about the fate of frequently poached animals like Asian elephants and black rhinos.

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The study calculated the rate at which extinctions are occurring against how long on average it takes a species to evolve successfully. Basically, they wanted to know how long it would take for evolution to bring us back to current biodiversity levels.

After the next 50 or 100 years, it will take nature 3-5 million years just to get back on track as of 2018. However, it would take the Earth 5-7 million years to restore the animal kingdom to a variety existing before us pesky humans appeared.

Of course, that's not a guarantee either, because it's based on the assumption that humans will eventually stop ruining animal habitats and the extinction rate will sink again. Knowing us though, that's not likely.