USING MITOCHONDRIAL AND NUCLEAR-DNA MARKERS TO RECONSTRUCT HUMAN-EVOLUTION

Molecular genetic data have greatly improved our ability to test hypot heses about human evolution. During the past decade, a large amount of nuclear and mitochondrial data have been collected from diverse human populations. Taken together, these data indicate that modern humans a re a relatively young species. African populations show the largest am ount of genetic diversity, and they are the most genetically divergent population. Modern human populations expanded in size first on the Af rican continent. These findings support a recent African origin of mod ern humans, but this conclusion should be tempered by the possible eff ects of factors such as gene flow, population size differences, and na tural selection. BioEssays 20:126-136, 1998. (C) 1998 John Wiley & Son s, Inc.