Evolution & Genetics

Both Church and State had good reason to support belief in the immutability of the social hierarchy, and from ancient times this was carried over into theological argument about the natural world. The basis of family resemblance and the mechanism of selecting desirable features of domestic animals and plants by breeding were not understood until Mendel's experiments in the 19th century, but Darwin deduced the effect of natural selection by observation.

The impact of genetics on medical practice was already profound even before molecular technology permitted analysis of the entire human genome.