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13 Cards in this Set

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Why is diversity higher as you get to the equator?

The climate: the cold slows down the chemical reactions by the poles. There is more sugar produced in the equator

in tropics..

-Main way to survive is competition


-low competition, low rates of reproduction

reasons for high genetic diversity

-old population


-frequent immigration


-many genetically diverse founders


-environmentally allows for survival of many alleles

reasons for low genetic diversity

-young population


-immigration lacking or rare


-few founders (or genetically similar founders)


-natural selection allows only a few alleles to persist

Loss of alleles

- genetic drift


-natural selection


-founder effect & genetic bottleneck


-non-random breeding (includes inbreeding)

Genetic drift (or allelic drift)
-is the change in the frequency of a gene variant (allele) in a population due to random sampling of organisms.
Natural selection
-is the gradual process by which heritable biological traits become either more or less common in a population as a function of the effect of inherited traits on the differential reproductive success of organisms interacting with their environment. It is a key mechanism of evolution.

founder effect

-loss of genetic variation that occurs when a new population is established by a very small number of individuals from a larger population.
population bottleneck
-is an event that drastically reduces the size of a population

-may be caused by various events, such as an environmental disaster, the hunting of a species to the point of extinction, or habitat destruction that results in the deaths of organisms.

nonrandom mating
- in which individuals with similar genotypes and/or phenotypes mate with one another more frequently than would be expected under a random mating pattern

-For example, it is common for individuals of similar body size to mate with one another.

gain alleles

-mutations: make up alleles


-gene flow: population


--alleles gained


--alleles lost


---loss more, more diversed

measurements of genetic variation among populations

-within population variation (the difference between members of a single population


-populations have a similar genetic variation

Homospiens

-Africa


- more genetic diversity in chimpanzees