The Vadoma or Wadoma (singular Mudoma), are a tribe living in the Zambezi River valley . Their way of life has hardly changed, still maintaining a semi nomadic lifestyle, raising livestock and subsistence farming. They are a shy, reserved people with little contact with the outside world, preferring to maintain their traditional ways in their isolated homeland.
A substantial minority of this tribe has a condition known as ectrodactyly in which the middle three toes are absent and the two outer ones are turned in, resulting in the tribe being known as the “two toed” or “ostrich footed” tribe. This is an autosomal dominant condition resulting from a single mutation on chromosome number seven. It is reported that those with the condition are not handicapped and well integrated into the tribe. The condition prevails because of a small genetic pool among the Vadoma, and is propagated by the tribal law that forbids members to marry outside the group. Thus this condition is much more frequent than elsewhere.

The Kalanga of the Kalahari desert also have a number of members with ectrodactyly, and may be related.
Ectrodactyly appears throughout the world. It is caused by various human gene defects. It is also associated with hearing loss. It occurs in 1 out of 90,000 births while limb defects occur in roughly 1 in 1,000 births, which by comparison is slightly less than the occurrence of identical twins.