Chapter 16 Vocab

Front 1

population genetics

Back 1

the study of evolution from a genetic point of view.

Front 2

bell curve

Back 2

a graph of the frequency of lengths in a population. called a bell curve because the shape of the curve looks like a bell.

Front 3

gene pool

Back 3

the total genetic information available in a population.

Front 4

allele frequency

Back 4

determined by dividing the number of a certain allele by the total number of alleles of all types in the population.

Front 5

phenotype frequency

Back 5

is equal to the number of individuals with a particular phenotype divided by the total number of individuals in the population.

Front 6

Hardy-Weinberg genetic equilibrium

Back 6

allese frequencies in a population tend to remain the same from generation to generation unless acted on by outside influences.

Front 7

immigration

Back 7

the movement of individuals into a population.

Front 8

emigration

Back 8

the movement of individuals out of a population.

Front 9

gene flow

Back 9

the process of genes moving from one population to another.

Front 10

genetic drift

Back 10

the phenomenon by which allese frequencies in a population changes as a result of random events, or chance.

Front 11

assortative mating

Back 11

The selection of a mate based on similarity of characteristics

Front 12

stabilizing selection

Back 12

individuals with the average form of a trait have the highest fitness.

Front 13

directional selection

Back 13

individuals that display a more extreme form of a trait have a greater fitness than individuals with and average form of the trait.

Front 14

disruptive selection

Back 14

individuals with either extreme variation of a trait have greater fitness than individuals with the average form of the trait.

Front 15

sexual selection

Back 15

females choose the males they mate with based on certain traits.

Front 16

morphology

Back 16

the internal and external structure and appearance of an organism

Front 17

speciation

Back 17

the process of species formation. results in many related populations of organisms.

Front 18

biological species concept

Back 18

a species is a population of organisms that can successfully interbreed but can not breed with other groups.

Front 19

geographic isolation

Back 19

the physical separation of members of a population. canyons can form between members or a river or something.

Front 20

reproductive isolation

Back 20

results from barriers to successful breeding between population groups int eh same area.

Front 21

prezygotic isolation

Back 21

occurs before fertilization. (first type of reproductive isolation.)

Front 22

postzygotic isolation

Back 22

occurs after fertilization. (second type of reproductive isolation.)

Front 23

punctuated equilibrium

Back 23

a change occurred in a few thousand, rather then million years