Anthropology 201 Final

main lecture concepts

scientific method

basic idea Brough forth by the Greeks

catastrophism

a set of organisms was wiped out by catastrophe and another replaced them

uniformitarianism

the earth is very old and dynamic, things we see impacting the world today have always existed

doomsday

eventually humans will outstrip the resources in the world, populations push up against available resources

Charles Darwin's postulates

1. Ability of a population to expand is infinite, but the ability of the environment to support populations is always finite

2. Organisms within populations vary, and this variation affects ability of organisms to survive and reproduce

3. Variation is transmitted from parents to offspring

adaptation

a trait that enhances reproductive success (fitness)

Directional selection

occurs when individuals with traits on one side of the mean in their population survive better or reproduce more than those on the other

Stabilizing selection

a type of natural selection in which genetic diversity decreases as the population stabilizes on a particular trait value

individuals

Natural selection acts on

Hardy-Weinberg equilibrium

Under certain assumptions, both the frequencies of alleles as well as the frequencies of genotypes, will remain constant from generation to generation

forces of evolution

natural selection, mutation, genetic drift, gene flow

founder effect

the reduced genetic diversity which results when a population is descended from a small number of colonizing ancestors

Biological species concept

species are groups or organisms that naturally or potentially interbreed in nature and are reproductively isolated

Reproductive isolation

individuals from one group do not breed successfully with those from another group, prevents gene flow, maintains differences between groups

Allopatric

speciation occurring via geographic isolation

Sympatric

speciation occurring in the same geographic location

Convergent evolution

occurs when species occupy similar ecological niches and adapt in similar ways in response to similar selective pressures

Divergent evolution

what occurs when two groups of the same species evolve different traits within those groups in order to accommodate for differing environmental and social pressures

clumped

valuable patches, constant competition, dominance relationship

dispersed

low-value patches, scrambled competition, alliances

females

male fitness depends on

food

female fitness depends on

care, competition, cooperation

strategies to enhance reproductive success

intersexual selection

selection favors traits that make males more attractive to females

65 mya

primates enter the scene in Cenozoic

mosaic evolution

the occurrence, within a given population of organisms, of different rates of evolutionary change in various body structures and function

Bipedal H1

efficient way to travel on ground for apes

Bipedal H2

Good way to keep cool in open country

Bipedal H3

leaves hands free for carrying things

Bipedal H4

efficient for harvesting food from small trees

Bipedal H5

adaptation for locomotion on flexible branches