- Silviene F. Oliveira1 & Luzitano B. Ferreira2
1 Department of Genetics and Morphology, University of Bras’lia, Brazil.
2 Post Graduation Program, University of S‹o Paulo, Brazil.
Eubios Journal of Asian and International Bioethics 14 (2004), 60-63.
In biology, race can be defined as a geographically bounded population showing accentuated genetic differentiation. It is believed that the division of human species into "races" presents solid biological base. However, there are problems over using this term. The present work aims to point out some of the difficulties of using the concept of races for the human species, using a biological approach. The race concept is typological, imprecise, based on subjective concepts, and can suffer different interpretations according to the criteria used, who is using it, and even the time and place of the determination. The chosen characteristics for the conception of races are usually in accordance to the convenience of the user, based on external and extremely complex morphologic criteria, with little support of genetic knowledge. This concept is also static, and does not represent the modifications and evolution of human populations, with the same evolutionary origin. Most populations are not circumscribed, so that there is genetic flux among them, leading to genetic differences not big enough to support the sub-division of the human species into races. The genetic differences among human groups are smaller then between individuals of the same population. From this biological point of view, the existing inconsistency for the classification of the human species in different races, make the morphological criteria used nowadays nonsense.
The human being feels the need of classifying everything around us. Even though the first classifications of the species are from immemorial times, it is known that the philosophers separated the beings in aerial, terrestrial and aquatic domains or whether they are useful or hazardous to humans. In the biological classification proposed by Linneaus, still used today, the species are separated in categories, going from the most broad (rein) until the most specific (species). The subdivision of different populations of a species is denominated subspecies, correct designation of what we call "race". This concept was first introduced to human populations by the French biologist Buffon, as an arbitrary classification that was used simply like a label and not like a scientific entity (1).
The term "race" has several concepts in biology. In agreement to Mayr (2), race is a sympatric population, not interrelating, that differs in its biologic characteristics, but is does not differ in morphologic characteristics. Futuyma (3) states that race is a vague and meaningless term, for a set of populations occupying a particular region that differ in one or more characteristics from populations elsewhere, frequently equivalent to subspecies. Race is also defined as a circumscribed population with accentuated genetic differentiation.
Historically, the division of the human beings in races was used not only to classify and try to better comprehend the different populations, but most of all to justify the exploration and oppression of people considered "biologically inferior". For example, the Amerindians were considered not civilized during all the American colonization (4). For at least 50 years, between 1850 and 1900, the American census contributed directly to the generation of scientific ideas of race that were the base of the racial speech that justified and supported the slavery and segregation (5).
Although the race concept can, in some few cases, be used to reveal inequities between human groups, the utilization of this concept in medical sciences can contribute to ideas of biologic determinism (6) and complicate diseases diagnosis (7). Moreover, stereotypes associated to certain ethical groups can produce distinct behavior among health professionals, resulting in less access to health services (8), diagnosis exams of high technology (9) and treatment (10).
Because of its concept, there is a belief that the distinction of human being has a solid base in biologic evidences. Nevertheless, there are several problems for the utilization of this concept by the biologic point of view. Because of this, the purpose of the present investigation was to verify the difficulties of the utilization of the race concept for human populations.
The first problem in the conception of human races, in agreement with Futuyma (11), is the need of having populations circumscribed geographically. The human specie migrates by nature and expanded through all the continents since its origin. A brief partial isolation permitted the beginning of the differentiation of the species. Nevertheless, mainly after the beginning of the Great European Navigations, any type of isolation was capable to be broken. With the innovation and increase of the transports this possibility reached unimaginable levels in few decades ago. Besides, trying to apply only geographic criteria for the designation of human races is not adequate because, as stated Cartmill (12), if "black", "white", "asiatic" and amerindians individuals that are born in the same place are different by the racial point of view, so the races are not distinct geographically. On the other hand, if these individuals constitute a race, the races are not distinct phenotypically.
The definition of race is imprecise, extremely broad and submitted to several interpretations in agreement to the criteria to be utilized. There is not a specific criteria that can guarantee to populations the designation of race, which is taking lots of systems to propose the abandon of the term (13). Applied to the human beings, this term corresponds to an arbitrary system of visual classification that does not demarcate distinct populations (14).
Race is a characteristic of convenience, which is used when there is the need to distinguish populations, which makes different criteria to be used by different classifying agents. Several characteristics and genetic polymorphisms show different geographic patterns with the possibility of several combinations to distinguish one population from another (15). The recent number of human races identified can vary from 3 to 200 (16).
The classification of human beings depends on who and where the evaluation is made. Anthropologists that lecture in institutions that are not from the elite and that had a social origin less privileged tend to be more receptive to the position of non existence of races than their colleagues from elite institutions (17). In England, "Asiatics" correspond to people that come from India, Pakistan and Bangladesh, whereas in the United States, it describes people from Pacific Islands, China and Japan (18). A person with European ancestry born in Mexico could be classified as "white" in all the countries of Latin America, whereas in the United States would probably receive the classification of "latino" or "hispanic".
The definition of some races can change with the time. In the Unites States, in the beginning of immigration, Irish and Italians were considered "not-white" being afterwards classified as "caucasians" (19). Mexicans were considered "white" in decades of 1940 and 1950 (20), being nowadays designated as "hispanics".
Classification is not elucidative and can obscure the human diversity. Frequently there are utilized broad and vague terms for the definition of races, which can include several populational groups by the point of view of origin, culture and ancestrallity under the same designation. The American census of 1990 set ten subcategories for Asiatics and natives from the Pacific Islands, but none for "whites", which answered for 80% of the population (21). The term "asiatic" utilized in the United States can underestimate several populational groups, making the great part of the world population o be seen as one (22).
Frequently the criteria utilized for the racial classification is not adequate. Generally there are used extern morphologic characteristics not very representative genetically. In one study with a "white" brazilian population, it was verified the contribution of 28% of afro-descendents and 28% of amerindian in the total pool of mitochondrial DNA, which is inherited from the mother (23). In one study of a "black" population of Pittsburgh, in the United States, it was verified the presence of 25% of genes considered as "caucasians" (24). In other American cities, the mixture of "European genes" in afro-descendents ranged from 11.6% to 22.5% (25). In one afro-descendent brazilian population, considered "black", in the Amazonic region, morphologic parameters verified the presence of 14% of mixture individuals, whereas in the study of 12 genetic markers of blood groups the mixture reached 24% (26). In the same population, studies with markers of chromosome Y, of paternal origin, verified the presence of 43% of mixture and with mitochondrial DNA, of maternal origin, a mixture of 47% (27).
The color of the skin, as well as the color and the shape of the hair and eyes, used in the races classification, are polygenic and multifactorial characteristics not yet understood by the biologic point of view (28). It is a characteristic of continuous variation that does not allow the categorization in classes. The levels of just one pigment known as melanin are responsible for the production of several shades in the humanity. The environment and age are factors extremely important in the definition of the color of a person which turns very difficult to associate a certain phenotype to a genotype (29). The interaction with the environment is individual, that is, depends on the history of life of each person, despite being similar to individuals inhabiting the same geographic region.
Race is a typological concept and is based upon ideal, nonexistent types in the nature. Being a static concept, based upon fixed types, race cannot explain the complex changes of structures in the biologic human variation (30). Besides, the classical vision of race implies in a homogeneous group of individuals where the members are similar biologically among them and differ from members of other groups, which does not occur, because members of certain group possess great genetic variations (31).
It is important to remember that the concept of race emerged in a time when it was believed that the World was constant and unchangeable since the moment of its creation. The beings did not modify or evolve. The classification were only to better adequate the beings in the Scala Naturae, or Great Scale of the Beings. This scale was considered permanent, unchangeable and did not present defects or lacuane (32). Thus, the different human population, considered unchangeable, not only was adequate but also should be differentiated in this Scala Naturae. This static concept is not consistent with the continuous process of biological evolution. The biological human variation, as well as of the other species is continuous, complex and changeable.
Comparing the human populations with other species, it is observed that the human specie is the one that presents one of the smallest values of genetic diversity. This fact is a direct consequence of the high rate of dispersion, migration, as well as the short time of evolutive history of our specie. Comparing the human being with species of mammals with power of dispersion, we see that the human differences are not high, even with the great distribution of the human population. The human beings show a modest level of genetic differentiation and this level of differentiation is below from what is conventionally written of what separate races (33).
Only recently we can test the existence of races in more precise biological terms, with the advance of genetics and molecular biology. Data show that the differences between human populations are not enough to classify them as races.
The results of extensive genetic studies of several human populations from different continents show the fragility of the concept of race, because it was verified that the human diversity was higher inside the "racial" or geographic groups than among them. Lewontin, analyzing populations from distinct continents, concluded that 85% of the human genetic diversity occurred inside the populations or races (34). In 1980, studying the populations of Europe, Africa, Middle Orient, Asia, America and Oceania, Latter (35) verified that the diversity inside the populations was nearly 84%, among populations of one group 6% and only 10% among the geographic groups. Others studies with several populations and different markers had the same conclusion (36,37).
No one can deny that Homo sapiens is a specie markedly differentiated; few argue the observation that the differences in the color of the skin is the most obvious sign of this variability. But the variability does not request the designation of race, in the case of our specie, it does not occur in levels that allow this designation. This point of view does not imply that there is not a variation among populations that compose our species, but this variety is not characterized as race (38).
Race is a social and not a biological concept, with serious ethical implications. As mentioned by Varma (39), the history of Eugenia presents scientific questions related to race and ethnicity, despite the benevolent intentions, can take to the legitimacy of discriminatory stereotypes.
The classification of human beings in different races is not based upon biological differences, is imprecise, convenient for those that do the classification, generally does not auxiliate a better comprehension of human groups, does not inform with precision our evolutionary history and is not based in genetic differences among human population. This division, arbitrary and artificial, emphasizes the small differences among populations with their stereotypes and prejudices, and not supplying a better comprehension of the human being.
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