Term
| 4 processes that can shift allele frequencies in a population over time |
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Definition
1. natural selection
2. genetic drift
3. gene flow
4. mutation |
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Term
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Definition
| a group of individuals from the same species that live in the same area at the same time & can interbreed & that vary in the traits they possess |
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Term
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Definition
| a single group of all of the alleles from all the gametes produced in each generation |
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Term
| Hardy-Weinberg principle: allele frequencies expression |
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Definition
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Term
| Hardy-Weinberg principle: genotype frequencies expression |
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Definition
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Term
| 5 assumptions that must be met for the Hardy-Weinberg model |
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Definition
1. random mating
2. no natural selection
3. no genetic drift (random allele frequency changes)
4. no gene flow
5. no mutation |
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Term
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Definition
| the mating between relatives |
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Term
| inbreeding increases _____ |
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Definition
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Term
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Definition
| alleles that lower fitness |
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Term
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Definition
| the decline in average fitness that takes place when homozygosity increases & heterozygosity decreases in a population |
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Term
| 2 causes of inbreeding depression |
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Definition
1. many recessive alleles represent loss-of-function mutations
2. many genes - especially those involved in fighting disease - are under intense selection for heterozygote advantage, a selection process that favors genetic diversity |
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Term
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Definition
| changes the average value of a trait; the average phenotype of a population changes in one direction |
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Term
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Definition
| reduces variation in a trait; reduce both extremes in a population |
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Term
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Definition
| increases variation in a trait; opposite of stabilizing selection; favors extreme phenotypes at both ends of the range of phenotypic variation |
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Term
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Definition
| maintains variation in a trait; occurs when no single allele has a distinct advantage |
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Term
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Definition
| when disadvantageous alleles decline in frequency |
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Term
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Definition
| heterozygous individuals have higher fitness than homozygous individuals |
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Term
| frequency-dependent selection |
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Definition
| certain alleles are favored when they are rare, but not when they are common |
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Term
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Definition
| the selection of an individual of one gender for mating by an individual of the other gender |
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Term
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Definition
| individuals compete with one another to obtain mates |
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Term
| 2 things which females may choose mates based off of |
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Definition
1. physical characteristics that signal male genetic quality
2. resources or parental care provided by males |
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Term
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Definition
| an area that is actively defended & that provides exclusive or semi-exclusive use by the owner |
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Term
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Definition
| any trait that differs between males & females |
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Term
| ecological/environmental selection |
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Definition
| favor traits that enable organisms to do things other than obtain mates - such as survive in their physical & biological environments |
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Term
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Definition
| any change in allele frequency in a population that is due to chance |
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Term
| genetic drift is random with respect to _____ |
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Definition
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Term
| genetic drift is most pronounced in _____ |
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Definition
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Term
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Definition
| a specific allele that causes a distinctive phenotype |
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Term
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Definition
| a change in allele frequencies that occurs when a new population is established |
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Term
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Definition
| a sudden reduction in the number of alleles in a population |
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Term
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Definition
| an allele that allows individuals to produce more offspring |
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