Genetics-And-Evolution-Evolution-3
Evolution:
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Process of gradual change in living organisms over time.
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Driven by natural selection, genetic variation, and other mechanisms.
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Evidence includes the fossil record, homologous structures, vestigial organs, molecular biology, and biogeography.
Speciation:
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The process by which new species emerge from existing ones.
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Two types: allopatric (geographic isolation) and sympatric (within the same area).
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Involves isolation barriers, genetic drift, and natural selection.
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Crucial for biodiversity and understanding species formation.
Reproductive Isolation:
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Mechanisms preventing interbreeding between different species.
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Includes prezygotic (before fertilization) and postzygotic (after fertilization) barriers.
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Maintains genetic distinctiveness of species.
Hardy-Weinberg Equilibrium:
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A mathematical model to study population genetics.
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Conditions for equilibrium: no mutations, gene flow, large population, random mating, and no natural selection.
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Helps analyze genetic variation within populations.
Factors in Evolution:
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Mutation: Source of genetic variation.
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Natural Selection: Advantageous traits spread.
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Genetic Drift: Random allele frequency changes in small populations.
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Gene Flow: Gene movement between populations.
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Adaptation: Development of traits enhancing fitness.
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Extinction: Species disappearance due to environmental changes or competition.
