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Definition
| • A group of organisms from the same species in the same localized area |
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Term
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Definition
• Sum of all the different genes available within a population
• Describes specific alleles present in a population |
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Term
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Definition
• Describes characterists of a population where frequency of alleles won’t change (nonevolving)
• Use either frequency of three genotypes in a population or frequency of each of the alleles if you have one or the other
• p2 + 2pq + q2 = 1; p + q = 1
• p = proportion of dominant allele; q = frequency of recessive allele
• p2 = homozygous dominant genotype, 2pq = heterozygous, q2 = homozygous recessive |
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Term
| Preconditions for Hardy-Weinberg Equation |
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Definition
• Frequency of alleles within a population doesn’t shift
• Large population
• No migration in or out of population
• Random mating
• No mutations
• Natural selection doesn’t affect survival of organisms based on the allele
• Therefore it’s basically just theoretical |
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Term
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Definition
• Change in frequency of alleles within a population attributable to chance
• Describes evolution in the absense of natural selection
• Bottleneck effect, founder efffect
• Doesn’t necessarily lead to relative fitness or evolution |
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Term
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Definition
• Example of genetic drift
• Size of population is drastically reduced by some event, not necessarily resulting in a gene pool that resembled the original |
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Term
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Definition
• Example of genetic drift
• A small number of individuals populate a new area
• Less of an effect if gene flow is involved |
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Definition
• Genetic movement between two populations (share alleles)
• Leads to evolution
• e.g. two populations previously separated are now joined; pollen blown by the wind |
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Term
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Definition
• Random changes in an organism’s DNA that make new alleles for a gene
• Must be in sex cells to be passed on to offspring
• Unless bottleneck or something, usually won’t cause evolution in a population |
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Term
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Definition
• Differences between organisms that are more or less able to survive or reproduce in an environment
• Attributes make them better able to survive or reproduce they’re more relatively fit than others
• Natural selection favors this strong force for evolution |
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Term
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Definition
• Natural selection shifts overall genetic makeup of a population toward one end
• For example, if darker mice are favored because of an environmental factor |
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Term
| Diversifying/Disruptive Selection |
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Definition
• Natural selection shifts phenotypes to extremes of a range
• Like if being super bright or super dark helps you survive |
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Term
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Definition
• Natural selection hurts extreme phenotypes of a population
• Like if being a muted color helps you survive |
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Term
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Definition
• Adaptations that were useful to an organism at one point, are still present, and no longer serve a purpose
• e.g. an appendix or pelvis of some marine creatures
• Supports evolution |
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Term
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Definition
• The process that causes two populations to diverge into two different species of organisms
• A species is the populations of organisms that are capable of breeding to produce viable offspring, but the lines get really blurry
• Allopatric speciation, sympatric speciation |
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Term
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Definition
• Live in different places/different daily routine/different niche/don’t want to mate
• Temporal isolation: e.g. two populations flowering at different times of day
• Anatomical barrier from mating
• Can’t produce a fertilized egg when they mate
• Offspring can’t reproduce |
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Definition
• Creation of species when a population is somehow separated by a geographic barrier
• One species before, then split and evolve differently, can’t inbreed once reunited |
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Definition
• Speciation without any form of geographic segregation
• More rare than allopatric speciation
• Perhaps a sudden mutation in a population among only some individuals |
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Definition
• Two species emerge as only slightly different at first
• Accumulate small differences that make them into very different species over time
• Evolution is a slow, steady process
• What Darwin thought, older theory |
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Term
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Definition
• Majority of differences between two species emerge shortly after divergence
• After that they won’t change very much
• Evolution comes in bursts!
• Newer theory, trendy with evolutionary biologists today |
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