Throughout evolution, one species has kept another in check. This has worked well for untold generations. And for millions of years. Until the late arrival of the human species. It has kept all species in check, except its own. Whence all its problems. Once a species comes on top of the evolutionary chain, it must keep itself in check, too. By hook or by crook. Or else. Let us hope the human species has learnt this simple biological lesson for the next round of evolution.

Addendum (August 14, 2017)

The only check worth mentioning the human species has come up with so far is simple enough: war. As of late, two world wars have been the only periods when the planet has had a respite from the abominable species. But the third one is liable to be the greatest check of them all. And it will be followed by untold local wars across the entire globe. Behold, the mother of all checks. All the problems facing the planet will disappear as if by miracle. And in one fell swoop. Hey, who is to say that the human species has not learned the key biological lesson? Cut out his lying tongue!