Mixed Race Studies

Skin color is historically the locally adaptive trait most commonly considered by European cultures as a “racial trait” in humans. Skin color is an adaptation to the amount of ultraviolet (uv) radiation in the environment: dark skins are adaptive in high uv environments in order to protect from radiation damage that can kill and burn cells and damage DNA if not protected by melanin, and light skins are adaptive in low uv environments in order to make sufficient vitamin D, which requires uv (Hochberg & Templeton, 2010; Jablonski & Chaplin, 2010). The geographical distribution of skin color follows the environmental factor of uv intensity. Skin color differences do not reflect overall genetic divergence. For example, the native peoples with the darkest skins live in tropical Africa and Melanesia. The dark skins of Africans and Melanesians are adaptive to the high uv found in these areas. Because Africans and Melanesians live on opposite sides of the world, they are more highly genetically differentiated than many other human populations (Figure 2) despite their similar skin colors. Europeans, who are geographically intermediate between Africa and Melanesia, are likewise intermediate at the molecular genetic level between Africans and Melanesians, even though Europeans have light skins that are adapted to the low uv environment of Europe. Skin color differences in humans are not a reliable indicator of overall genetic differentiation or evolutionary history. Moreover, skin color varies continuously among humans in a clinal fashion rather than categorical ecotypes (Relethford, 2009). Hence, there is a compelling biological reason to exclude skin color as the racially-defining adaptive trait under the ecotype concept of race.

Alan R. Templeton, “Biological races in humans,” Studies in History and Philosophy of Science Part C: Studies in History and Philosophy of Biological and Biomedical Sciences, Volume 44, Issue 3, September 2013. 262–271. http://dx.doi.org/10.1016/j.shpsc.2013.04.010.

Biological races in humans

Studies in History and Philosophy of Science Part C: Studies in History and Philosophy of Biological and Biomedical Sciences
Volume 44, Issue 3, September 2013
Pages 262–271
DOI: 10.1016/j.shpsc.2013.04.010

Alan R. Templeton, Charles Rebstock Professor of Biology Emeritus
Washington University in St. Louis, St. Louis, Missouri

Highlights

• Races are highly genetically differentiated populations with sharp geographical boundaries.
• Alternatively, races can be distinct evolutionary lineages within a species.
• By either definition, races do not exist in humans but do exist in chimpanzees.
• Adaptive traits such as skin color do not define races and are often discordant with one another.
• Humans populations are interwoven by genetic interchanges; there is no tree of populations.

Races may exist in humans in a cultural sense, but biological concepts of race are needed to access their reality in a non-species-specific manner and to see if cultural categories correspond to biological categories within humans. Modern biological concepts of race can be implemented objectively with molecular genetic data through hypothesis-testing. Genetic data sets are used to see if biological races exist in humans and in our closest evolutionary relative, the chimpanzee. Using the two most commonly used biological concepts of race, chimpanzees are indeed subdivided into races but humans are not. Adaptive traits, such as skin color, have frequently been used to define races in humans, but such adaptive traits reflect the underlying environmental factor to which they are adaptive and not overall genetic differentiation, and different adaptive traits define discordant groups. There are no objective criteria for choosing one adaptive trait over another to define race. As a consequence, adaptive traits do not define races in humans. Much of the recent scientific literature on human evolution portrays human populations as separate branches on an evolutionary tree. A tree-like structure among humans has been falsified whenever tested, so this practice is scientifically indefensible. It is also socially irresponsible as these pictorial representations of human evolution have more impact on the general public than nuanced phrases in the text of a scientific paper. Humans have much genetic diversity, but the vast majority of this diversity reflects individual uniqueness and not race.

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PAGE ONE — No Biological Basis For Race, Scientists Say / Distinctions prove to be skin deep

San Fransisco Gate Chronicle
1998-02-23

Charles Petit, Chronicle Science Writer

This is one of a series of articles in “About Race,” a year-long public journalism project in which The Chronicle, KRON-TV, BayTV and KQED-FM are examining various aspects of race relations in the Bay Area.

The President’s Initiative on Race, designed to attack prejudice by bringing people of different races together to talk, may have overlooked something.

Namely, that the very concept of race is bogus and has no basis in biology, according to most scientists.

“This dialogue on race is driving me up the wall,” said Jefferson Fish, a psychologist at St. John’s University in New York who has written extensively about race in America. “Nobody is asking the question, ‘What is race?’ It is a biologically meaningless category. It is a cultural term that Americans use to describe what a person’s ancestry is…

…Despite this, many Americans still believe in three great racial groups, a system developed in Europe and North America in the 18th century…

…If anything, the president’s initiative should have been on racism, say the scientists. For, even without race, racism can exist as a belief that ancestry is a significant factor in cultural and behavioral differences among peoples…

…In years past, children of mixed marriages “were assigned the racial (and legal) status of the more subordinate parent,” said Faye Harrison, an anthropologist at the University of South Carolina [now University of Florida].

“That rule, called . . . the ‘one drop rule’ (for one drop of blood), has worked to classify me as African American, period,” said Harrison. “Despite the fact that I, like most other African Americans I know, have a mixed heritage and mixed ‘race’ genealogy. But that multicultural or multiracial reality is part of my extended family’s private transcript, not our public identity as blacks, as African Americans.”

Studies show that the ancestry of American blacks is about 70 percent African, with the rest European and American Indian….

Read the entire article here.