The Chillingham Wild Cattle, comprising between 130 and 140 animals at present, are unique in the world
in that they have existed in the vicinity of Chillingham Castle in Northumberland for hundreds of years.
They are entirely left alone, no handling, no earmarks, no veterinary assistance, and they are a scientific curiosity.
They share about 92% of their genetic make up as they have been inbred since the Middle Ages,
and yet they do not develop weird features (misformations) that one would expect in the circumstances.
Charles Darwin was interested in the phenomenon, too.