As humans migrated across the world, they encountered new environments requiring them to adapt to new challenges that presented themselves. The distribution of human phenotypes observed today is the result of this continuous adaptation, via biological/physiological and cultural means, and also by the modification of cultural practices, which leads to biological changes. In this chapter, we examine a number of adaptive traits and the roles played by their genetic and environmental determinants. We have selected a few traits used for human identification purposes (externally visible characteristics), associated with human metabolism and linked to a shift in subsistence method and food consumption. We discuss the evolutionary processes that have affected the temporal and spatial distribution of these traits, including natural, sexual, and cultural selection.