The Afrikaner population of South Africa is mainly descended from one shipload of
immigrants which landed in 1652. The early colonists included individuals with a
number of rare genes. The ship of 1652 contained a Dutch man carrying the gene for
Huntington's disease, an autosomal dominant disease which does not appear until the
sufferer is over 40 years old and leads to certain death within five to 10 years. Today,
the Afrikaner population has an unusually high frequency of the gene that causes
Huntington's disease, because those original Dutch colonists just happened to carry
that gene with unusually high frequency.
anism of evolution is this?
Reproductive isolation
Founders effect
Co evolution
Bottle neck