Paul D Stewart / Illustration of Cowslips (Primula veris) from 'Darwinism' by Alfred Wallace 1889. In 1862 Darwin reported how Primula plants have two forms of flowers, pin and thrum eyed, differing in the height and...

Mark Bowler / White Tiger (Panthera tigris) captive in Zoo, mutation caused by severe inbreeding.

Mark Bowler / White Tiger (Panthera tigris) captive in Zoo, mutation caused by severe inbreeding.

Fiona Rogers / Western chimpazee (Pan troglodytes verus) infant male 'Flanle' aged 3 years riding on his mothers back - note six digits to right hand which may be a result of inter breeding within such a small commu...

LYNN M. STONE / A white, cross-eyed Bengal Tiger cub (Panthera tigris tigris) captive