Modern Human Variation and “Race”
Modern Human Variation and “Race”
- When you think of 60 thousand years in evolutionary times, that a very short time
Modern Human Variation
- Beginning 60 kya, anatomically modern humans expanded to occupy every region of the
- Modern humans inhabit areas showing a wide range in ecological and climatic conditions
- In places like Toronto, it’s easy to see the diversity of our species
o It is coming primarily from this period of time
- In this lecture, we will review the extend, the pattern and the meaning of variation in
modern humans, and we will also discuss historic attempts to understand this diversity
A Little Bit of History…
- Attempts to classify humans according to their physical characteristics go back
thousands of years.
- One of the first “scientific” attempts was that of Carolus Linnaeus, the founder of
modern taxonomic classification.
o He also invented bionomial classification (genus, species)
o This is an effort that goes back thousands of years
- It is very instructive to review in some detail Linnaeus’ 18 century classification of
Linnaeus 1758 Classification of Humans
- Americanus: reddish, choleric, and erect; hair black, straight, thick; wide nostrils, scanty
beard; obstinate, merry, free; paints himself with fine red lines; regulated by customs.
- Asiaticus: sallow, melancholy, stiff; hair black; dark eyes; severe, haughty, avaricious;
covered with loose garments; ruled by opinions.
- Africanus: black, phlegmatic, relaxed; hair black, frizzled; skin silky; nose flat; lips
tumid; women without shame, they lactate profusely; crafty, indolent, negligent; anoints
himself with grease; governed by caprice.
- Europeaeus: white, sanguine, muscular; hair long, flowing; eyes blue; gentle, acute,
inventive; covers himself with close vestments; governed by laws.
About the Linnaeus Classification
- Probably, it has immediately struck you that the Linnaeus classification:
o Is based on superficial physical traits, such as skin color, hair color and shape,
eye color and other facial traits.
o It is also based on “cultural” features (more properly, on biased and Eurocentric
18 century preconceptions about cultural characteristics of broadly defined
Perception of the group according to that age (i.e. some groups are
st cocky, women have no shame)
- Under our 21 century eyes, the Linnaeus classification seems a complete nonsense and
utterly ridiculous. Unfortunately…
From Linnaeus to the Present
- The classification of humans based on superficial physical traits (which we now know are
subjected to strong selective forces), and perceived cultural features has continued during th th
the 19 and the 20 centuries, and even today…. often with dramatic consequences, such
o Slavery and its everlasting effects
o Eugenic policies of the early 20 century.
o The atrocities committed by the Nazis in WWII
o Discrimination across the world
Johann Blumenbach (1752-1840) - not part of slides
- Father of physical anthropology
- Wrote On the Natural Variety of Mankind in 1776
- Established 5 human races that represented the human types:
o Mongolian (yellow)
o American (red)
o Caucasian (white)
o Malayan (brown)
o Ethiopian (black)
- Used a more biological approach. Rejected multiple origins. Rejected African
inferiority. Also recognized the continuous nature of human variation
Human variation and Race
- What is “Race”?
- The problem with this concept is that term means different things to different people
Some Background on the Term “Race”
- The French physician Francois Bernier (1684) was tone of the first scientists that used
the word “race” in its modern context (not part of the slides but very important)
- The term “race” was coined by Buffon, a French naturalist, in 1745.
- The word “race” has different meanings for different people. For some it has mainly a
cultural meaning, for others, both a biological and a cultural component…
- We will only discuss here the biological concept of race. But first, how can we define
race in this narrow biological sense? Do races exist? Can race explain the biological
variation found in humans?
The Biological Concept of Race
- Biological races could be defined as “unambiguous, clearly demarcated, biologically
- Another possible definition could be: “a division of a species that differs from other
divisions by the frequency with which certain hereditary traits appear among its
members” (Brues, 1977).
- So, do biological races exist in humans
Do Biological Races Exist?
- The majority of anthropologists agree that there are no biological races in humans.
- You may want to check the statements of the two main North American Anthropological
associations about this issue.
- Statement of the American Association of Physical Anthropologists (AAPA) on
biological aspects of race
- Statement of the American Anthropological Association (AAA) on race
o http://www.aaanet.org/stmts/racepp.htm There are some of the Reasons
- Races are, by definition, discrete units, which are used to explain variation that is mostly
continuous in nature.
o Evolution is complex, and there are many different factors that influence
o The variation in humans (and any species) and be described with the interplay
with the evolutionary factors
- Consequently, racial classifications can’t explain in any meaningful way the variation
observed in human populations.
o This is why there has never been an agreement among anthropologists on the
number of human “races”: from three to several dozens….
- “Biological variation is real; the order we impose on this variation by using the concept
of race is not” (Relethford, 2002).
o Variation exist, but creating these descriptive categories doesn’t explain the
complex reality of human variation (or species)
An Example with Skin Pigmentation – The Simplistic View… And the Reality…
- In reality, there is going to be a huge range of variation of skin tones, and there is also
overlap between groups
More Problems with the “Race” Concept
- The traits that have been traditionally employed to classify humans in “racial” groups are
anthropometric traits (primarily skin color, features of the face, and the shape and size
of the head and body, and the underlying skeleton).
- However, anthropometric traits are strongly influenced by the environment, and are
subjected to natural selection, which may be acting in different ways for different traits.
o Natural selection acts in specific genomes
- Thus, different traits often show remarkably discordant geographical distributions.
An Interesting Example: Skin Pigmentation versus…
- There is darker skin in the darker regions,
and lighter skin as you move north in terms of
Distribution of the B Allele of the ABO Blood Group
- Frequency of allele B, has a east west
distribution with high frequencies in Asia
- Low frequency of allele B is found in
the Americas You Can See That…
- The distribution of skin