Genetic Variation and Adaptation in Africa: Implications for Human Evolution and Disease

Abstract

Because modern humans originated in Africa and have adapted to diverse environments, African populations have high levels of genetic and phenotypic diversity. Thus, genomic studies of diverse African ethnic groups are essential for understanding human evolutionary history and how this leads to differential disease risk in all humans. 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 and are useful for identifying patterns of genetic variation that have been influenced by recent natural selection. Here we describe what is currently known about genetic variation and evolutionary history of diverse African ethnic groups. We also describe examples of recent natural selection in African genomes and how these data are informative for understanding the frequency of many genetic traits, including those that cause disease susceptibility in African populations and populations of recent African descent.

Demographic Events and Evolutionary Forces Shaping European Genetic Diversity

“…For example, in East Africa, other instances of the lactase persistence variant have arisen in the LCT genomic region, and, in high latitudes of Asia, other variants in different genes that lighten skin pigmentation have spread to high frequency (see review in Gomez et al 2014). Therefore, it seems that when distant human populations are faced with similar selection pressures, independent evolutionary responses can take place.…”

Does maternal race influence the short-term variation of the fetal heart rate? An historical cohort study

“…284 Finally, genetic variation is substantially greater among black 285 women from sub-Saharan Africa than white Europeans [36]; it is 286 thus conceivable that each African ethnic group within these 287 countries has its own STV threshold, and that our study lacks the 288 power to show this.…”

“…STV 30 is the best predictive criterion for fetal well-being [5,7], and the 31 relation between reduced STV and the degree of neonatal acidosis 32 has been demonstrated [5,7-9] Some authors have suggested that maternal race influences the 34 FHR parameters considered in standard visual FHR monitoring. 35 Accordingly, compared to the fetuses of white women, fetuses of 36 black women are significantly less reactive [10], have a higher 37 basal heart rate [11], and are more likely to have micro-fluctuating 38 or flat FHR during labor and delivery [12]. 39 To our knowledge, only one study has used computerized FHR 40 analysis to examine the influence of maternal geographic origin on 41 FHR variation.…”

Perspectives on Human Variation through the Lens of Diversity and Race: Figure 1.

“…In this collection, scholars of genetic variation and evolution in the major geographic regions of the world have outlined both known and more recent genetic studies (Gomez et al 2014;Majumder and Basu 2014;Ruiz Linares 2014;Veeramah and Novembre 2014). Their research, and the complementary works of others, allows us to make three major novel inferences.…”