All contemporary humans are members of the same polytypic species, Homo sapiens. A polytypic species is composed of local populations that differ in the expression of one or more traits. It’s crucial to emphasize that even within local populations, there’s a great deal of genotypic and phenotypic variation among individuals. Nevertheless, in discussions of human variation, most people typically have emphasized and grouped together various characteristics, such as skin color, face shape, nose shape, hair color, hair form (curly or straight), and eye color. Those individuals who have particular combinations of these and other traits have been placed together in categories associated with specific geographical localities. Traditionally, such categories have been called races. We all think we know what we mean by the word race, but in reality the term has had various meanings since the 1500s, when it first appeared in the English language. Race has been used synonymously with species, as in “the human race.” Since the 1600s, race has also referred to various culturally defined groups, and this meaning is still common. For example, you’ll hear people say, “the English race” or “the Japanese race,” when they actually mean nationality. Another phrase you’ve probably heard is “the Jewish race,” when the speaker is really talking about a particular ethnic and religious identity.
So, even though race is usually a term with biological connotations, it also has enormous social significance. And there’s still a widespread perception that certain physical traits (skin color in particular) are associated with numerous cultural attributes (such as occupational preferences or even morality). As a result, in many cultural contexts, a person’s social identity is strongly influenced by the way he or she expresses those physical traits traditionally used to define “racial groups.” Characteristics such as skin color are highly visible, and they make it easy to immediately and superficially place people into socially defined categories. However, so-called racial traits aren’t the only phenotypic expressions that contribute to social identity. Sex and age are also critically important. But aside from these two variables, an individual’s biological and/or ethnic background is still inevitably a factor that influences how he or she is initially perceived and judged by others.
References to national origin (for example, African, Asian) as substitutes for racial labels have become more common in recent years, both within and outside anthropology. Within anthropology, the term ethnicity was proposed in the early 1950s to avoid the more emotionally charged term race. Strictly speaking, ethnicity refers to cultural factors, but the fact that the words ethnicity and race are used interchangeably reflects the social importance of phenotypic expression and demonstrates once again how phenotype is mistakenly associated with culturally defined variables. In its most common biological usage, the term race refers to geographically patterned phenotypic variation within a species. .By the seventeenth century, naturalists were beginning to describe races in plants and nonhuman animals. They had recognized that when populations of a species occupied different regions, they some times differed from one another inexpression of one or more traits. But even today, there are no established criteria for assessing races of plants and animals, including mans. As a result , biologists now almost never refer to “races” of other species but more typically talk about populations or, for major subdivisions, subspecies.
Before World War II, most studies of human variation focused on visible phenotypic variation between large, geographically defined populations and these studies were largely descriptive. But in the last 60 years or so, the emphasis has shifted to examining the differences in allele frequencies(and more basically DNA differences ) with in and between populations as well as considering the adaptive significance of phenotypic and genotypic variation. This shift in focus occurred partly because of the Modern Synthesis in biology. But now armed withgenome data sets for populations, biologists have an unprecedented opportunity to study and explain human variation and the role that evolutionary factors have played in producing it(Pritchard,2010).
In the twenty first century, the application of evolutionary principles to the study of modern human variation has replaced the superficial nineteenth century view of race based solely on observed phenotype. Additionally, the genetic emphasis has dispelled previously held misconceptions that races are fixed biological entities that don’t change over time and are composed of individuals who all conform to a particular type. Clearly, there are visible phenotypic differences between humans, and some of these roughly correspond to particular geographic allocations. But we need to ask if there’s any adaptive significance attached to these differences. Is genetic drift a factor? What is the degree of underlying genetic variation that influences phenotypic variation? What influence has culture had in the past ? These questions place considerations of human variation within a contemporary evolutionary biocultural framework.
Although, as a discipline, physical anthropology is rooted in attempts to explain human diversity, no contemporary scholar subscribes to pre Modern Synthesis concepts of races (human or nonhuman) as fixed biological entities. Also, anthropologists recognize that such out dated concepts of race are no longer valid, because the amount of genetic variation accounted for by differences between groups is vastly exceeded by the variation that exists within groups. Many physical anthropologists also argue that race is a out dated creation of the human mind that attempts to simplify biological complexity by organizing it in to categories. So, human races are a product of the human tendency to impose order on complex natural phenomena. In this view, simplistic classification may have been an acceptable approach 100 years ago, but given the current state of genetic and evolutionary science, it’s meaningless.
However, even though racial categories based on outwardly expressed variations are invalid, many biological anthropologists continue to study differences in such traits as skin or eye color because these characteristics, and the genes that influence them, can yield information about population adaptation, genetic drift, mutation, and gene flow. Forensic anthropologists, in particular, find the phenotypic criteria associated with race (especially in the skeleton) to have practical applications. Law enforcement agencies frequently call on these scientists to help identify human skeletal remains. Because unidentified human remains are often those of crime victims, identification must be as accurate as possible. The most import ant variables in such identification are the individual’s sex , age, stature, and ancestry(“racial” and ethnic background).Using metric and nonmetric criteria, forensic anthropologists employ various techniques for establishing broad population affinity (that is, a likely relationship) for a particular individual, and for most applications their findings are accurate about 80 percent of the time (Owsley et al., 2009).
Another major limitation of traditional classification schemes derives from their inherently typological nature, meaning that categories are distinct and based on stereotypes or ideals that comprise a specific set of traits. So in general, typologies are inherently misleading because any grouping always includes many individuals who don’t conform to all aspects of a particular type. In any so-called racial group, there are individuals who fall into the normal range of variation for another group based on one or several characteristics. For example, two people of different ancestry might differ in skin color, but they could share any number of other traits, including height, shape of head, hair color, eye color, and ABO blood type. In fact, they could easily share more similarities with each other than they do with many members of their own populations (Fig. 14-1).
To blur this picture further, the characteristics that have traditionally been used to define races are polygenic; that is, they’re influenced by more than one gene and therefore exhibit a continuous range of expression. So it’s difficult, if not impossible, to draw distinct boundaries between populations with regard to many traits. This limitation becomes clear if you ask yourself: At what point is hair color no longer dark brown but medium brown, or no longer light brown but dark blond? (Look back at Figure 4-16 for an illustration showing variability in eye color.) The scientific controversy over race will fade as we enhance our understanding of the genetic diversity (and uniformity) of our species. Given the rapid changes in genome studies, and because very few genes actually contribute to outward expressions of phenotype, dividing the human species into racial categories isn’t a biologically meaningful way to look at human variation. But among the general public, variations on the theme of race will undoubtedly continue to be the most common view of human biological and cultural variation. Keeping all this in mind, it’s up to anthropologists to continue exploring the issue so that, to the best of our abilities, accurate information about human variation will be available to anyone who seeks informed explanations of complex phenomena