Caucasians

Through multiple analyses of mitochondrial and nuclear DNA, as well as specific alleles and other polymorphic traits, biological anthropologists and geneticists have shown that biologically distinct racial groups or subspecies do not exist within the human species, Homo sapiens. Instead, racial categories are arbitrary, socially constructed, and culturally defined labels that vary between societies and have shifted in their terminologies and classification schemes over time. No clear-cut scientific consensus has ever delineated a precise number of human races, with some early-20th-century scholars and social observers proposing the existence of three races (Caucasoid, Negroid, Mongoloid), while others argued for the existence of five, nine, or several dozen racial groups.

The highly subjective nature of racial taxonomy, which is influenced by the establishment of arbitrary standards as racial boundaries, renders impossible any objective attempt of human racial classification. From the late 18th to the mid-20th century, racial theorists known as “lumpers” have proposed racial typologies consisting of a relatively small number of human races based largely along continental lines (European, African, Asian, American Indian, etc), while “splitters” have simultaneously put forth more elaborate racial classification models that subdivided major continents into more specific, regional racial groupings (e.g., northern Europeans, central Europeans, southern Europeans).

Although human biological variation is real, attempts to pigeonhole such tremendous physical and genetic variation into a finite number of human categories is not. This is because much human phenotypic and genetic variation is continuous, or clinal, in nature and occurs over a series of gradations between neighboring indigenous populations, rather than manifesting itself in a few distinct, discrete types. As one such example, human skin color does not occur in just five, 15, or even 55 different shades. Rather, the range of human skin color, as a continuous trait, constitutes a spectrum from very light to very dark, with every possible hue, shade, and tone in between manifesting itself among various members of the species. Central Africans generally have darker skin pigmentation than north Africans, who in turn are generally darker than southern Europeans. Southern Europeans tend to be slightly darker than northern Europeans. In addition to skin color, other physical traits such as hair color, hair texture, height, nose shape, and eye color are also clinal traits.

Furthermore, genetic research reveals that of the total amount of genetic diversity found within the human species, approximately 88 to 92 percent exists within any continental region (Europe, Africa, Asia, etc.). Only 8 to 12 percent of the total amount of human genetic diversity is found between these continental regions that are often assumed to be the homelands of distinct racial groups. As such, significantly more genetic diversity is found within presumed racial groups than between such groups. In order for race to hold biological significance, the opposite must be true—more genetic discrepancies must exist between groups than within. Nevertheless, the belief in biological races remains a powerful idea in the United States, and issues of race constitute some of the most vexing and emotional social and political topics in the nation.