RACE, BIOLOGY, AND HUMAN DIVERISTY

1
RACE, BIOLOGY, AND HUMAN DIVERISTY

• Is race a myth?

2
Questions about Seeing Daylight

• Are the Tlingit a race?
• If not, to what race do they belong?
• What do we mean when we the word race?

3
Race is a biological concept

• Race is a geographically (hence, reproductively)
  isolated subdivision of a species, or subspecies.
• If reproductive isolation lasts long enough, then
  a new species is produced.

4
Do human races exist?

• Human populations have not been reproductively
  isolated long enough to have developed into
  biological races.
• Early human classification into races have been
  dependent solely on the evaluation of phenotype
  (manifest biologyappearance, skin color, hair
  texture, etc.).

5
The Standard Geographical Groupings of Races

• Negroid or AfricanAfrica.
• CaucasoidEurasia.
• MongoloidAsia and Americas.
• AustraloidAustralia and Oceania.
• Each group is based on differences in appearance
  (skin color, hair texture, body form, etc.)

6
Geographic types are ambiguous

• Only 6 of human genes account for the
  phenotypical differences seen between races.
• Greater overall variation exists within each
  racial grouping than between such groups.
• The phenotypic traits that do exist are largely
  adaptive in nature.

7
Distribution of Type O blood
8
How does the previous map compare with the
Biasutti Skin Color Map?

• Look at Map 9 in your atlas. If human races were
  as distinct as many have assumed, should
  shouldnt there be some correlation between skin
  color and blood type?
• Skin color is a function of melanin production in
  the dermis layer of the skin. Skin coloring is
  adaptive.

9
Skin pigmentation, Vitamin D, and survival

• Vitamin D not common in nature the human body
  synthesizes it in the skin with the help of
  ultraviolet radiation.
• Vitamin D is necessary for directing the bodys
  use of calcium.
• Too much Vitamin D is toxic too little will
  result in debilitating bone disease.
• Skin pigmentation levels monitors Vitamin D
  production.

10
Dark skin protects skin from excessive
ultraviolet radiation

• Northern populations, with little sunlight,
  require minimal pigmentation to produce Vitamin
  D.
• Tropical populations require protection from too
  much ultraviolet radiation and too much Vitamin
  D.
• Light skinned people are maladapted for tropical
  areas.

11
Summary about human variation

• Human variation essential for survival of the
  species.
• Some differences attributed to races the result
  of biological adaptive response to climate to
  certain regions of the world.
• Humans groups have never been isolated long
  enough to form true biological races.

12
Social Constructions of Race

• Social races are groups assumed to have true
  biological differences based on culturally
  arbitrary rather than scientific assessment.
• Examples blacks and whites. What is a black
  race? A white race?
• Racial categorization in American culture A
  child of mixed parents (one black and one white)
  is socially labeled as black, even though
  genetically, the child could just as easily be
  considered white (genotype 50/50).

13
Rule of Hypodescent

• Descent is the assignment of social identity
  based on ancestory.
• Hypodescent is the American cultural practice of
  placing the children of parents representing
  different groups (mixed marriages) in the
  minority status.
• Example Louisiana law states that anyone with
  1/32nd black ancestry is legally black.

14
The Pervasiveness of Hypodescent

• The flap over Miss Saigon for the New York
  production Jonathan Pryce, a caucasian actor,
  could not play the role of a French/Vietnamese
  pimp. The actor needed to be Asian.

15
Race and the U.S. Census

• Race tracked in the U.S. since 1790, since slaves
  counted as 3/5th of a white person and Indians
  were not taxed.
• New census has a place for considering multiple
  racial affiliations.
• Canada visible minorities vs. race

16
Hypodescent in Japan

• Pure Japanese 90 of the population.
• Japanese say Koreans smell different.
• Burakumin, although genetically indistinguishable
  from other Japanese, are considered unclean, and
  segregated into separate communities.

17
Other approaches toward race Brazil

• Brazilians use up to 500 different racial labels.
• Class status, though, is based on skin color.
• Dark skin suggests hard labor, but money
  lightens.
• Brazil lacks racial aversion.
• In spite of racial admixture, hypodescent never
  developed.

18
Race and Intelligence

• 19th century arguments for racial superiority
  have survived to some degree (Nazi Germanys pure
  Aryan race.). Class-based societies perpetuate
  the myths, in part to fuel segregation and
  domination.
• Povertyminorityunintelligent has been
  reinforced by unscientific testing.
• Culture and environment appear to be the factors
  at work, not innate intellectual potential.

19
Conclusions

• A great level of human biological diversity
  exists, although more variation occurs within
  geographical groups than between.
• Most social definitions of race are based on
  phenotype, although some may be mythological.
• Innate intelligence varies from individual to
  individual, irrespective of ancestry. Most
  testing has cultural bias.