Species either evolve or become extinct. Extinctions happen all the time, but in the planet’s history there have been five extinctions where the majority of species died off. These extinction events were the critical events that saw the shift from reptiles to mammals, from plants to animals, and from life that was killed by oxygen that was produced by life that needed oxygen. The extinctions we are witnessing are not the norm. The rate of extinction is, conservatively, ten to a hundred times greater than normal. Taken as data, this trend suggests we are at the beginning of a sixth extinction event. We are the most likely cause, but that doesn’t mean that our species is immune. The sixth extinction event may include us.
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