Vadoma
Encyclopedia
The Doma, also Vadoma or Wadoma (singular Mudoma), are a tribe living in the west of Zimbabwe
, especially in the Urungwe and Sipolilo districts on the Zambezi
river valley. They have few contacts with the Bantu majority.
A substantial majority 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. Indeed it may help in tree climbing. The Kalanga
of the Kalahari desert also have a number of members with ectrodactyly, and may be related.
The Vadoma are a popular example of the genetic effects of small population size on genetic defects and mutation, in a case of blatant inbreeding depression
. Due to the Vadoma tribe's isolation, they have developed and maintained ectrodactyly, and due to the comparatively small gene pool, the condition is much more frequent than elsewhere.
Zimbabwe
Zimbabwe is a landlocked country located in the southern part of the African continent, between the Zambezi and Limpopo rivers. It is bordered by South Africa to the south, Botswana to the southwest, Zambia and a tip of Namibia to the northwest and Mozambique to the east. Zimbabwe has three...
, especially in the Urungwe and Sipolilo districts on the Zambezi
Zambezi
The Zambezi is the fourth-longest river in Africa, and the largest flowing into the Indian Ocean from Africa. The area of its basin is , slightly less than half that of the Nile...
river valley. They have few contacts with the Bantu majority.
A substantial majority of this tribe has a condition known as ectrodactyly
Ectrodactyly
Ectrodactyly, sometimes referred to as the “Lobster-Claw Syndrome” involves the deficiency or absence of one or more central digits of the hand or foot and is also known as split hand/split foot malformation...
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
Chromosome
A chromosome is an organized structure of DNA and protein found in cells. It is a single piece of coiled DNA containing many genes, regulatory elements and other nucleotide sequences. Chromosomes also contain DNA-bound proteins, which serve to package the DNA and control its functions.Chromosomes...
number seven. It is reported that those with the condition are not handicapped and well integrated into the tribe. Indeed it may help in tree climbing. The Kalanga
BaKalanga
The Kalanga, also known as the Bakalanga are one of the first Bantu speaking tribes to migrate to present day Botswana, followed by the Bakgalagadi and then the Batswana . The Kalanga had first settled in Mapungubwe in South Africa, the first Kalanga state. They later moved to the Great Zimbabwe...
of the Kalahari desert also have a number of members with ectrodactyly, and may be related.
The Vadoma are a popular example of the genetic effects of small population size on genetic defects and mutation, in a case of blatant inbreeding depression
Inbreeding depression
Inbreeding depression is the reduced fitness in a given population as a result of breeding of related individuals. It is often the result of a population bottleneck...
. Due to the Vadoma tribe's isolation, they have developed and maintained ectrodactyly, and due to the comparatively small gene pool, the condition is much more frequent than elsewhere.