anthropology week 3

Genetic variation

Phenotype

Genotype + environment = Phenotype

All variation is cause by:

.non-adaptive change

. Randomness(mutation, drift, flow)

Different degrees of captive change

Human genetic variation vs phenotype variation between any

Two hunan there is only about .1% difference in genes

Between any two chimpanzees there is as much as 1.2% differnce in genes

Common misconeptions

Humans naturally sort into separate races

Different races differ in very obvious ways

Different between race relates underlying genetic difference

Race and ethnicity

Race: when a ethic group is assumed to have a biological basis

Racism: discrimination against such a group

Race is a cultural category rather than a biological reality

Difficult to make precise distinction between race and ethnicity

Is race biology

Race = subspecies

Group of individuals that share a common ancestor

Geographically isolate from other member of their species

Not genetically isolated from other members of their species

Members possess discrete characteristics not possessed by other members of there species

Monotype species

No distinct population or race (no subspecies)

Polytypic species

Two or more population that are clearly distinct from one another and do not generally interbreed, but whoich would interbreed freely if given the change to do so

Cline

A continuum with an infinite number of gradation from one extreme to the other

Continuous variation

Measurements of a phenotypic traits which from a continuous spectrum of values

Discontinuous variation

Traits that are either present of absent, with no intermediate

Like have a simple genetic basis

Sexual dimorphism

Difference in morphology between in morphology individuals if different sex within the same species