[R]esearchers have uncovered recent traces of adaptation to malaria in the DNA of people from Cabo Verde, an island nation off the African coast.
An archipelago of ten islands in the Atlantic Ocean some 385 miles offshore from Senegal, Cabo Verde was uninhabited until the mid-1400s, when it was colonized by Portuguese sailors who brought enslaved Africans with them and forced them to work the land.
The Africans who were forcibly brought to Cabo Verde carried a genetic mutation, which the European colonists lacked, that prevents a type of malaria parasite known as Plasmodium vivax from invading red blood cells. Among malaria parasites, Plasmodium vivax is the most widespread, putting one third of the world’s population at risk.
People who subsequently inherited the protective mutation as Africans and Europeans intermingled had such a huge survival advantage that, within just 20 generations, the proportion of islanders carrying it had surged, the researchers report.
Other examples of genetic adaptation in humans are thought to have unfolded over tens to hundreds of thousands of years. But the development of malaria resistance in Cabo Verde took only 500 years.