Today, Alan Turing is best known as the father of modern computer science, but in 1952 he sketched out a biological model in which two chemicals — an activator and an inhibitor — could interact to form the basis for everything from the color patterns of a butterfly’s wings to the black and white stripes of a zebra.

It was an innovative hypothesis, made all the more impressive by the fact that it was postulated without the benefit of modern molecular biology — the double-helix structure of DNA wouldn’t be discovered for another year.