Race

I

Introduction

Race, largely discredited system of classifying human beings according to common descent and superficial physical characteristics. The concept of race is not particularly helpful biologically or sociologically: all so-called races belong to the one biological species Homo sapiens and show only minor genetic variations. Culture is considered a far more important factor than race in determining behaviour and lifestyle. The high profile of the issue of race is a result of the political uses of notions of superiority associated with racism.

As a biological concept, race was clearest when distinctions were made by reference to morphological traits, such as skin pigmentation, hair form, shape of nose, and body form. The arrival of genetic analysis blurred the picture. Before genetic definition the classification of races depended on a combination of geographic, ecological, and morphological factors; However, the progressive use of genetic analysis (see below) showed that gene variants, or alleles, were indifferent to such boundaries and allowed race to intermingle through intermediate forms. With increased mobility and interbreeding it became clear that the number of races was in principle infinite, and the whole concept of race suspect.

No two human beings, not even twins, are identical. The proportions of human traits and, to an extent, even the kinds of traits are differently distributed from one part of the world to another. In the past, when people travelled less and marriages were likely to be between neighbours, races tended to develop and be retained as geographical entities. Although some historic conceptions of race were thus based on geographical variation in physical traits such as skin colour and hair form, such traits can accurately be used to ascribe a person to a race only insofar as they were inherited from ancestors belonging to the population in question.

Every individual has two biological parents, four grandparents, eight great-grandparents, and so on, increasing to many billions of ancestors as far back as ancient times. However, the world did not then contain that many people; most early ancestors, if known, would appear over and over again as progenitors of many different lines of descent. This is what is meant by inbreeding. Inbreeding helps to maintain both a degree of separation among sub-populations and a degree of similarity within such populations. Human experience also includes countless instances of outbreeding with members of other groups. Thus, over time, it becomes impossible to separate one race from another.

II

Adaptions to Environment

Individuals of different continents and of smaller geographical areas, however, do tend to differ. Their differences include inherited characteristics, some of which may reflect adaptations to the different environments in which the ancestors of the present individuals lived for many generations. Although the concept of genetic adaptation is still debated, it seems likely that human beings may adapt biologically to such conditions as temperature, altitude, prevalent diseases, and dietary resources.

A

Temperature and Altitude

The human response to the stress of a hot environment is to sweat. Hair, especially coarse, tightly curled head hair, may provide some protection from direct sunlight. Armpit hair may retain sweat where its evaporation will cool the body. Racial groups do not seem to vary in terms of the number of sweat glands, but peoples of hot, dry climates, where sweating is especially important, tend to be tall and slim, that is, of a body build that exposes a maximum amount of skin to potential cooling by sweating. People of warmer regions also tend to have darker skin, a possible protection from damage from direct sun. Indeed, over many millennia, individuals with favourable adaptations to heat and perpendicular solar rays may have had a selective advantage for survival in tropical regions such as sub-Saharan Africa and South Asia.

In Arctic regions, a stocky body build and generally large body size are more common, and these traits apparently help in conserving body heat. Light-coloured skin may be less susceptible than dark skin to frostbite. Narrow noses serve better than broad noses in warming cold air before it enters the lungs. All these advantageous traits are more common in northern peoples such as the Inuit and Saami. Nevertheless, basic physiological responses to cold (shivering, for instance) occur in the same way in all human groups, and the most significant human adaptations to climate—clothes, houses, and the use of fire—are cultural, not biological.

High altitudes strain the human respiratory system. Some peoples living in high altitudes seem to have larger chests and lung capacities, and it is possible that in some mountainous zones, such as the Andes (but not, it seems, in the Himalaya), people may have a hereditary tendency to an especially well-developed respiratory system. On the other hand, all people born and reared at high altitudes or acclimatized by long residence in such an environment tend to develop their lung capacity, as well as having an increased number of oxygen-bearing red corpuscles in their blood.

B

Disease and Diet

Human response to disease and diet is extremely complicated. Any genetic racial differences in this regard are quite likely to be modified by cultural factors that influence the procuring and rationing of food and the spread of infectious disease. The most plausible instance of adaption to disease is the greater frequency in malarial environments of some genetic traits that foster resistance to malaria. These include genetic variations in the haemoglobin (such as sickle-cell haemoglobin and haemoglobin C) and an enzyme deficiency of red blood cells that apparently makes those cells less prone to infection by malarial parasites. Genetic differences may also exist in susceptibility to other once-common diseases such as bubonic plague, smallpox, and typhus; such differences may have become common in places where these diseases led to a greater number of deaths among individuals who lacked certain genetic traits. The geographical—that is to say, racial—differences now found in blood groups, blood serum proteins, and other human traits may be the remaining signs of the past adaptations to geographical variations in diseases.

III

Classification of Races