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

The Study of Living Peoples  What are the results of our species’ evolution on the life histories-- the “personal evolution”- - of the human individual?  What basic data do we gather in order to describe human populations?  How do we recognize evolutionary changes in populations and identify and study their causes?

McGraw-Hill © 2008 The McGraw-Hill Companies, Inc. All Rights Reserved The Study of Living Peoples  What sorts of trends can we see in populations within our species? In what ways have we humans adapted to the varying environments in which we live?  How have diseases influenced human populations?

McGraw-Hill © 2008 The McGraw-Hill Companies, Inc. All Rights Reserved The Study of Living Peoples  Bioanthropology of Individuals  Individuals don’t evolve, at least not in the sense that we are using the term here.  And yet bioanthropologists are interested in growth rates, developmental rates, and the timing of important events in the lives of individual members of our species.  Why is this information important to bioanthropology?

McGraw-Hill © 2008 The McGraw-Hill Companies, Inc. All Rights Reserved definitions  Menarche  A woman’s first menstrual period.  Menopause  The end of a woman’s reproductive cycle.  Life History  The study of the timing of life cycle events such as fertility, growth, and death.

McGraw-Hill © 2008 The McGraw-Hill Companies, Inc. All Rights Reserved The Study of Living Peoples  Describing Populations  Populations are the units of evolutionary change, and so the nature of the groups we study cannot be separated from the evolutionary processes that affect those groups.

McGraw-Hill © 2008 The McGraw-Hill Companies, Inc. All Rights Reserved The Study of Living Peoples  What can we say from demographic statistics about the human species in general?  One thing is certain--our total population is going to increase.  Since the beginning of farming and animal domestication some 12,000 ya, the rate of increase of the human population has accelerated, jumping sharply with the Industrial Revolution of the eighteenth century.

McGraw-Hill © 2008 The McGraw-Hill Companies, Inc. All Rights Reserved Definitions  Demography  The study of the size and makeup of populations.

McGraw-Hill © 2008 The McGraw-Hill Companies, Inc. All Rights Reserved The Study of Living Peoples  Evolution within Populations  Today we are able to characterize populations and study their evolution at the most basic genetic level of the individual letters (the four bases) of the genetic code.  Difference in letters of the code are what distinguish alleles of a gene. Thus, we have the basis for eventually understanding our biological diversity.

McGraw-Hill © 2008 The McGraw-Hill Companies, Inc. All Rights Reserved The Study of Living Peoples  Population Adaptations  Humans have to deal with nearly every imaginable set of environmental circumstances the earth presents, and we have been doing this for just about as long as Homo sapiens has existed.  One would expect, therefore, that different populations of our species would be differently adapted to those various environments.  Obviously, most of our adaptations are cultural.

McGraw-Hill © 2008 The McGraw-Hill Companies, Inc. All Rights Reserved The Study of Living Peoples  Species Adaptations  As members of the same species, all humans certainly share many adaptations to variable conditions.  One important environmental variable is temperature.  Similarly, we are all exposed to ultraviolet radiation from the sun.  Humans are also exposed to varying levels of oxygen.

McGraw-Hill © 2008 The McGraw-Hill Companies, Inc. All Rights Reserved The Study of Living Peoples  Variation in Adaptations  Populations that inhabit hot climates tend to be linear in build, and those in cold areas tend to be stockier.  Populations closet to the equator have darker skin, and those farther away from the equator have lighter skin.

McGraw-Hill © 2008 The McGraw-Hill Companies, Inc. All Rights Reserved definitions  Melanocytes  Specialized skin cells that produce the pigment melanin.  Melanin  The pigment largely responsible for human skin color.

McGraw-Hill © 2008 The McGraw-Hill Companies, Inc. All Rights Reserved The Study of Living Peoples  Are All Variations Adaptively Important?  The distribution of blood types in the ABO system is a perfect example of a variation with no obvious relationship to the environment.  There seem to be no rhyme or reason to how the various frequencies of the phenotypes are dispersed around the world.

McGraw-Hill © 2008 The McGraw-Hill Companies, Inc. All Rights Reserved definitions  Antigens  Substances, such as proteins, that can trigger an immune response, for example, the production of an antibody.  Antibodies  Proteins in the immune system that react to foreign antigens.

McGraw-Hill © 2008 The McGraw-Hill Companies, Inc. All Rights Reserved The Study of Living Peoples  Disease and Human Populations  We tend to think of diseases as abnormalities, but diseases are as much a part of life as any other aspect of our biological world.  Since many diseases are caused by other living organisms- viruses, bacteria, and protozoa- and are carried by other species, they are really perfectly natural.

McGraw-Hill © 2008 The McGraw-Hill Companies, Inc. All Rights Reserved The Study of Living Peoples  Disease and Human Populations  Disease-causing species have adapted to the biology of their hosts, and the hosts at least attempt to adapt to the disease-causing species.  Diseases are thus excellent examples of evolutionary processes.

McGraw-Hill © 2008 The McGraw-Hill Companies, Inc. All Rights Reserved definitions  Epidemiological  Pertaining to the study of disease outbreaks and epidemics.

McGraw-Hill © 2008 The McGraw-Hill Companies, Inc. All Rights Reserved The Study of Living Peoples  Summary  While a major focus of bioanthropology is on the evolutionary history of the hominins, the study of the current product of that evolution-- modern Homo sapiens-- is also important.  We study living populations of our species from several different yet interrelated approaches.