Daniel spots a beetle outside and asks why he seems to see them everywhere.

The answer is more remarkable than he expected.

There are around four hundred thousand known species of beetles -- roughly one in four of all known animal species on Earth. Only several thousand mammal species are known. Roughly eleven thousand bird species. Even mammals, birds, and reptiles combined don't come close to beetles. And scientists describe thousands of new beetle species every year. The true number is likely much higher.

Beetles form the most species-rich order of animals. By a large margin.

This struck scientists as remarkable too. There is a famous story -- possibly apocryphal -- about a biologist named J.B.S. Haldane, one of the most brilliant evolutionary scientists of the twentieth century. A group of theologians asked him what hi ...