Inbred cattle don’t look bad at all

A herd of feral cattle in northern England may be a rare example of how a tiny group can overcome the dangers of inbreeding. This Chillingham herd, now with 49 members, probably hasn’t welcomed new genes for 300 years. In long-term isolation of some other species, harmful mutations have degraded reproductive success.

However, the Chillingham herd seems to have a history of healthy calving, say Peter Visscher of the University of Edinburgh and his colleagues.