Race and Genetics - Race and Physical Characteristics

Race and Physical Characteristics

Human skin color vary for different populations. The leading explanation is that skin colour adapts to sunlight intensities which produce vitamin D deficiency or ultraviolet light damage to folic acid. Other hypotheses include protection from ambient temperature, infections, skin cancer or frostbite, an alteration in food, and sexual selection. The gene that causes light skin color in Europeans is different from the gene that causes light skin in East Asians. Europeans have a different version of the SLC24A5 than East Asians possibly indicating that they evolved light skin independently.

The most widely used human racial categories are based on various combinations of visible traits such as skin color, eye shape and hair texture. However, some argue that many of these traits are non-concordant in that they are not necessarily expressed together. For example, skin color and hair texture vary independently. Some examples of non-concordance include:

• Skin color varies all over the world in different populations.
• Epicanthal fold are typically associated with East Asian populations but are found in populations all over the world, including many Native Americans, the Khoisan, the Sami, and even amongst some isolated groups such as the Andamanese.
• Lighter hair colors are typically associated with Europeans, especially Northern Europeans, but blond hair is found amongst a limited, small number of the dark skinned populations of the south pacific, particularly the Solomon Islands and Vanuatu.

Others argue that this is just an example of Lewontin's Fallacy. On the contrary, if several traits are looked at the same time, then today forensic anthropologists can classify a person's race with an accuracy close to 100% based on only skeletal remains.

A 2010 examination of 18 widely used English anatomy textbooks found that every one relied on the race concept. The study gives examples of how the textbooks claim that anatomical features vary between races.