Human Adaptation in Africa

by Alessia Ranciaro

Africa is the birthplace of anatomically modern humans and a continent of linguistic, cultural, environmental, phenotypic, and genetic diversity as well as the geographic origin of human migration across the globe within the last 100,000 years. Despite such high levels of diversity, African populations remain underrepresented in genetic studies, which have largely focused on individuals with European and Asian ancestry.

Because modern humans originated in Africa and African populations have adapted to diverse climates, diets, geographic environments, and pathogens, they have high levels of genomic and phenotypic diversity. Therefore, genomic and phenotypic studies of diverse African ethnic groups are essential for understanding human evolutionary history. In addition, comparative studies of genetic diversity within and between African ethnic groups creates an opportunity to reconstruct some of the earliest events in human population history. Within the past 10,000 years, most human populations have transitioned from a hunting-gathering life-style to practicing agriculture and pastoralism, resulting in rapid population growth, increased population densities, and an increase in infectious diseases. The selection pressures for adapting to local environments and new diets have resulted in population- or region-specific genetic variants that influence variable phenotypes.

In this presentation I will summarize some of the recent findings regarding African demographic history and regarding correlation between phenotypes and genotypes for important evolutionary traits in humans that have been influenced by recent natural selection such as lactose tolerance, taste perception and skin pigmentation.