West of Zimbawbe, near the Zambezi river, lives a relatively isolated tribe known as the Doma (Wadoma and Madumo), who have an interesting feature. A majority of its members were born with a genetic mutation known as ectrodactyly which affects the development of fingers and toes.
The conditon results from a mutation of chromosone number seven and causes a 'split ' or division in the digits, often resulting in a lobster-like appearance of the hands and feet. In the case of the Doma it is primarily the feet which are affected and their three middle toes are missing. As a result, the tribe has become known as the 'two-toed' or "ostrich" tribe. The mutation survives because the gene pool among the Doma is small and they live in relative isolation.