gene flow in humans
Monday 14 May 2007
Gene flow has been observed in humans. For example, in the United States, gene flow was observed between a white European population and a black West African population, which were recently brought together.
In West Africa, where malaria is prevalent, the Duffy antigen provides some resistance to the disease, and this allele is thus present in nearly all of the West African population.
In contrast, Europeans have either the allele Fya or Fyb, because malaria is almost non-existent. By measuring the frequencies of the West African and European groups, scientists found that the allele frequencies became mixed in each population because of movement of individuals.
It was also found that this gene flow between European and West African groups is much greater in the Northern U.S. than in the South.
Gayden T, Cadenas AM, Regueiro M, Singh NB, Zhivotovsky LA, Underhill PA, Cavalli-Sforza LL, Herrera RJ. The himalayas as a directional barrier to gene flow. Am J Hum Genet. 2007 May;80(5):884-94. PMID: #17436243#