McGraw-Hill © 2008 The McGraw-Hill Companies, Inc. All Rights Reserved

Human Biological Diversity  How are the two human sexes interpreted differently by different cultures, and how can we use this as a model for examining “racial” variation?  Is race a valid biological concept?

McGraw-Hill © 2008 The McGraw-Hill Companies, Inc. All Rights Reserved Human Biological Diversity  What is the scientific evidence for our statement that there are no biological human races?  What, then, are human races?  How can bioanthropology contribute to understanding some of the problems surrounding the idea of race?

McGraw-Hill © 2008 The McGraw-Hill Companies, Inc. All Rights Reserved Human Biological Diversity  Sex and Gender  Most human beings are unambiguously either biologically male or female.  As these two real categories of sex-- male and female-- are incorporated into various cultural systems, differences arise.

McGraw-Hill © 2008 The McGraw-Hill Companies, Inc. All Rights Reserved Human Biological Diversity  The identity, place, and role of males and females under different cultural systems vary according to the nature of those systems-- their economies, politics, family organizations, and abstract beliefs.  Thus, males and females of the human species become the men and women of a particular society practicing a particular culture.

McGraw-Hill © 2008 The McGraw-Hill Companies, Inc. All Rights Reserved definitions  Sex  The biological categories and characteristics of males and females.  Gender  The cultural categories and characteristics of men and women.  Folk Taxonomies  Cultural classifications of important items and ideas.

McGraw-Hill © 2008 The McGraw-Hill Companies, Inc. All Rights Reserved Human Biological Diversity  Why Are There No Biological Races Within the Human Species?  It is all too easy to agree that there are no human biological races because we don’t want them to exist. The nonexistence of definable racial groups coincides with and reinforces our ethical ideas of human equality. But wishful thinking cannot take the place of scientific rigor. We must be able to say why there are no races.

McGraw-Hill © 2008 The McGraw-Hill Companies, Inc. All Rights Reserved Human Biological Diversity  Race as a Biological Concept  To remain a single species all males and females of the group must be capable of interbreeding. Furthermore, there must be sufficient gene flow to prevent one or more groups from becoming completely isolated.

McGraw-Hill © 2008 The McGraw-Hill Companies, Inc. All Rights Reserved definitions  Polytypic  A species with physically distinguishable regional populations.  Subspecies  Physically distinguishable populations within a species.  Races  In biology, the same as subspecies. In culture, cultural categories to classify and account for human physical diversity.

McGraw-Hill © 2008 The McGraw-Hill Companies, Inc. All Rights Reserved definitions  Semispecies  Populations of a species that are completely isolated from one another but have not yet become truly different species.  Cline  A geographic continuum in the variation of a particular trait.

McGraw-Hill © 2008 The McGraw-Hill Companies, Inc. All Rights Reserved Human Biological Diversity  Human Phenotypic Variation  No matter what phenotypic trait one uses, the human species simply cannot be divided into distinct subgroups based on biological differences.  Nor will such a division show up if we use combinations of traits, because the distributions of traits are discordant- that is, a particular expression of one trait does not necessarily predict a particular expression of another.

McGraw-Hill © 2008 The McGraw-Hill Companies, Inc. All Rights Reserved Human Biological Diversity  Genetic Variation  When scientists genetically compared samples from traditional racial groups, they determined that the groupings accounted for only a small percentage of genetic diversity; in other words, there was actually little genetic differences among the groups.

McGraw-Hill © 2008 The McGraw-Hill Companies, Inc. All Rights Reserved Human Biological Diversity  Evolutionary Theory  Gene flow is the norm for our species, and as widespread as we are, we still manage to exchange enough genes--through intermediary populations-- to prevent any group of humans from being isolated long enough to evolve the differences sufficient for semispecies status.

McGraw-Hill © 2008 The McGraw-Hill Companies, Inc. All Rights Reserved Human Biological Diversity  What Then, Are Human Races?  Like gender categories, human races are folk taxonomies.  Cultures classify other people relative to themselves. Isolated societies with some knowledge that others exist will have a very simple racial classification: us and them.  Among more mobile or cosmopolitan groups, as the relations among people become more varied, the classifications become more complex.

McGraw-Hill © 2008 The McGraw-Hill Companies, Inc. All Rights Reserved Human Biological Diversity  Race, Bioanthropology, and Social Issues  Our folk taxonomies are powerful and influential. We respond to them often without realizing that they are our culture’s way of ordering our world and are not necessarily scientific universals.  By understanding what race is, and what it’s not, and by applying what we know about the workings of genetics and evolution, we will be better prepared to deal with the issues of race that confront us almost daily.

McGraw-Hill © 2008 The McGraw-Hill Companies, Inc. All Rights Reserved definitions  Racism  Judging an individual based solely on his or her racial affiliation.  Heritability  The amount of variation of a particular trait within a population that is caused by genetic, as opposed to environmental, differences.  Reification  Translating a complex set of phenomena into a single entity such as a number.

McGraw-Hill © 2008 The McGraw-Hill Companies, Inc. All Rights Reserved Human Biological Diversity  Summary  Human societies need to find order in and make sense of the environments in which they live. Cultural systems, therefore, translate objective reality into categories that have meaning to them.

McGraw-Hill © 2008 The McGraw-Hill Companies, Inc. All Rights Reserved Questions for further thought  Expand upon the brief discussion in the text concerning the identities and roles of the two genders in this culture. How would you characterize them? How have they changed during your lifetime? Do you see a need for further change? Why? How would it come about?