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22 Cards in this Set
- Front
- Back
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Microevolution
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Small Scale Change in allele frequencies that arise as an
1. outcome of mutation, 2. natural selection 3. genetic drift 4. gene flow ....or a combo of these |
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Gene Pool
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All members of a population represent the gene pool (genetic resources)
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Dimorphism
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Two forms of a trait
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Polymorphism
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Three or more forms of a trait
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Quantitative Difference
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Range in traits
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Fitness
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Organism’s contribution to the next generation’s gene pool
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Phenotype
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Outward appearance
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Genotype
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Actual genes or chromosomes
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Mutation
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-Evolution starts with mutation
-Mutation is the source of new alleles -Sexual reproduction spreads a mutation through a population Only mutation creates new alleles 3 types 1. Beneficial 2. Lethal 3. Neutral |
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Alleles
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One or More pairs of genes
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Genetic Equillibrium
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1. No Mutation
2. Population is infinitely large 3. Population is isolated from other populations of same species 4. Individuals mate at random 5. All individuals survive and produce the sane number of offspring |
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Directional Selection
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Allele frequencies shift in a consistent direction
ex. pesticides & antibiotics (rats) |
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Disruptive Selection
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Both extremes of a range are favored
ex. (black bellied seedracker) only hard & soft beaked birds only hard & soft seeds around |
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Balanced polymorphism
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Multiple alleles of a gene persist in the population
Ex. Sickle cell anemia and malaria |
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Sexual Diphormisn
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Two forms
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Gene Flow
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Physical Movement of alleles into and out of a population
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Emigration
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Population loose alleles
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Immigration
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Population gains alleles
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Genetic Drift
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Random change in allele frequencies brought about by chance
Random change leads to homozygotes and loss of diversity |
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Bottleneck
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Drastic reduction in population size
Ex. Disease or hunting wipe out all but few individuals |
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Founder's Effect
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A few individuals establish new population
Ex. Islands |
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Inbreeding
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Non-random mating among very close relatives
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