modern humans (homo sapiens) how is human diversity perceived? traditionally as distinctly different...
Post on 21-Dec-2015
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• Modern humans (Homo sapiens)
How is human diversity perceived?Traditionally as distinctly different races
• Many attempts to classify human diversity• Carleton Coon. 1965. The Living Races of Man• Five races proposed:
– Caucasians– Asians– Indiginous Australians– Black Africans– San or Bushmen from Africa
• How do biologists perceive races in non-human species?
• A biological race = a subspecies.
• Phenotypically diagnosable populations occupying allopatric subdivisions of the range of a species.
• These populations have accumulated different mutations.
• Therefore, they express different fixed characteristics.
Example of subspecies: ratsnake (Elaphe obsoleta
Discordant characterSystems: also found inhumans
Genetic differencesdon’t coincide withcolor pattern differences
• Human race concept.• There is no satisfactory biological definition of a
human race!• Misconception: there are character states
unique to particular groups of humans• The characters traditionally used are quantitative
characters with continuous variation.
“Racial” characters arequantitative characterscontinuous characterse.g. skin color
Phenotypic expressionin and among populationsgenerally fits a normal distribution
• All individuals have approximately the same number of melanocytes.
• Therefore, what is the basis of skin color differences?
• Can “races” be recognized based on skin color?