Ch 23

Front 1

population genetics

Back 1

study of genetic changes in pops; science of miscorevolutionary changes in pops

Front 2

modern synthesis

Back 2

a comprehensive theory of evolution emphasizing natural selection, gradualism and pops as the fundamental units of evol change; neo Darwinism

Front 3

population

Back 3

a group of indivs of 1 species that live in a particular geographic area

Front 4

species

Back 4

a group whose members posses similar anatomical characteristics and have the ability to interbreed

Front 5

gene pool

Back 5

the total aggregate of genes in a pop at any 1 time

Front 6

hardy weinber theorem

Back 6

an axiom maintaining that the sexual shuffling of genes alone cannot alter overall genetic makeup of a pop

Front 7

Hardy weinberg equilibrium

Back 7

the condition describing a nonevolving pop (one at genetic equilibrium)

Front 8

Hardy Weinberg equation

Back 8

a formula for calculating the frequencies of genotypes in a gene pool from the frequencies of alleles and vice versa

Front 9

microevolution

Back 9

a change in the gene pool of a popl from generation to generation

Front 10

genetic drift

Back 10

changes in the gene pool of a small pop due to chance

Front 11

bottleneck efefct

Back 11

genetic drift resulting from the reduction of a pop typically by a natural disaster, such that the surviving pop is no longer genetically representative of the original pop

Front 12

founder efefct

Back 12

genetic drift attributable to colonization by a limited number of indivs from a parent pop

Front 13

genetic flow

Back 13

loss or gain of alleles in pop due to migration of fertile indivs or gametes between pops

Front 14

mutation

Back 14

rare change in DNA of a gene ultimately creating genetic diversity

Front 15

gene diversity

Back 15

average percent of these loci are heterozygous

Front 16

nucleotide diversity

Back 16

measured by comparing nucleotide sequence of DNA samples from 2 indiv and then pooling data from many such comparisons of 2 indivs

Front 17

geographic variation

Back 17

differences in genetic structure between pops

Front 18

cline

Back 18

graded variation in some traits of indivs that parallels a gradient in the enviro

Front 19

balanced polymorphism

Back 19

the ability of natural selection to maintain diversity in a pop

Front 20

heterozygote advantage

Back 20

greater reproductive success of heterozygous indivs compared to homozygous; tends to perserve variation in gene pools

Front 21

frequency dependent selection

Back 21

a decline in the reproductive success of a morph resulting from the morph's phenotype becoming too coommon in a pop; cause of balanced polymorphism in pops

Front 22

neutral variation

Back 22

genetic diversity that confers no apparent selective advantage

Front 23

darwinian fitness

Back 23

the contribution an indiv makes to the gene pool of the next generation, relative to contributions of other indivs

Front 24

relative fitness

Back 24

the contribution of 1 genotype to the next gen compared to that of alternative genotypes for the same locus

Front 25

directiional selection

Back 25

natural selection that favors indivs at 1 end of the phenotypic range

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diversifying selection

Back 26

natural selection that favors extreme over intermediate phenotypes

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stabilizing selection

Back 27

natural selection that favors intermeidate variants by acting against extreme phenotypes

Front 28

sexual dimorphism

Back 28

special case of polmorphism based on distinction between the secondary sex characteristics of males and females

Front 29

intrasexual selection

Back 29

direct competition among indivs of 1 sex usually male for mates of opposite sex

Front 30

intersexual selection

Back 30

indivs of 1 sex usualy females are choosy in selecting thier mates from indivs of the other sex; mate choice