Evolutionary Factors
ANT 2000
Skin color is one of the most visible and variable traits among humans, and scientists have
always been curious about how this variation evolved. Both light and dark pigmentation of
the skin are beneficial. For example, darker skin is believed to help prevent some of the
negative impacts of exposure to ultraviolet light, while lighter skin can promote the synthesis
of vitamin D in regions with low exposure to ultraviolet light.
Legacy traits that give survival and reproduction benefits in a given environment are more
likely to be passed on to the next generation, and thus become more common as time
passes. On the other hand, “Although natural selection has favored certain traits in human
populations, it does not explain all genetic variation. Some physical characteristics, such as
eye color, confer no discernible reproductive advantages.” (Scupin 2020).
Different human populations that have lived for many generations in a particular place in the
world can present variations in certain characteristics. Despite these differences, all humans
are very closely related and share most of their biological characteristics. According to the
textbook, “Culture may even more directly influence human genetic variation through
religious beliefs, social organization, marriage practices, or prejudices” (Scupin 2020). Which
restricts marriage between different races and therefore restricts gene flow. Evidence from
different disciplines, such as anthropology, evolutionary biology, physiology, genetics, and
cell biology, can provide insights into what makes a human characteristic beneficial or
harmful in a given environment, how cultures affect biology and many more. Variations in
genes can generate differences in biological characteristics. By studying DNA sequences in
people from different populations, you can estimate when and where those variations arose.
Evolution can involve trade-offs, a modification in a gene that results in an adaptation to one
characteristic of the environment could mean a disadvantage with respect to another
characteristic of that same environment. “A number of factors combine to give human skin its
color. The most important of these is melanin, the dark pigment that primarily determines the
lightness or darkness of skin and is responsible for variations of tan, brown, and black skin
color” (Scupin 2020). “Melanin” is the collective term for a family of pigments found in most
organisms, from bacteria to humans. This suggests that melanin has a long evolutionary