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Natural Selection exam Flashcards

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Natural Selection exam
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  • Natural Selection

    A key mechanism of evolution where certain traits enhance survival and reproduction, leading to evolutionary changes in populations over time.
  • Observation 1 of Natural Selection

    Variation is inherited; not all organisms in a population are identical, and much of this variation is passed from parent to offspring.
  • Observation 2 of Natural Selection

    Species tend to overproduce offspring, more than the environment can support.
  • Inference 1 from Natural Selection Observations

    Certain traits will make survival and reproduction more likely, while others will make them less likely.
  • Inference 2 from Natural Selection Observations

    Traits that help organisms survive and reproduce will accumulate in the population, leading to evolution.
  • Example of Natural Selection

    Snowshoe hares with coat color variation; white hares are less camouflaged in areas with little snow, leading to higher predation rates.
  • Adaptation

    A trait that increases an organism's fitness in a particular environment.
  • Fitness

    The likelihood that an organism is able to survive and reproduce.
  • Relative Fitness

    Fitness measured in comparison to other organisms in the population.
  • Absolute Fitness

    The total number of offspring an organism produces.
  • Does natural selection introduce variation?

    No, natural selection selects from existing variation in the population.
  • What is required for natural selection to occur?

    Existing variation within the population.
  • How does the environment affect fitness?

    Fitness depends on the environment; traits that are advantageous in one environment may not be in another.
  • Population Evolution

    Populations evolve over time as the frequency of advantageous traits increases.
  • Do individuals evolve?

    No, individuals do not evolve; populations do.
  • How does natural selection affect populations over time?

    It increases the number of adaptations to the current environment.
  • What happens if the environment changes?

    The population will evolve as different traits become advantageous.
  • Overproduction

    The production of more offspring than the environment can support.
  • Variation

    Differences in traits among individuals in a population.
  • Camouflage

    An adaptation that allows organisms to blend in with their surroundings.
  • Example of Overproduction

    Female snowshoe hares can birth 12+ offspring per year, but not all survive.
  • What is the role of competition in natural selection?

    Members of the same species compete for resources, affecting which traits are passed on.
  • Probability in Natural Selection

    Survival and reproduction are based on probability; advantageous traits increase the likelihood of survival.
  • How does natural selection shape populations?

    It increases the frequency of advantageous traits, making populations better fit their habitats.
  • Darwin's 4 Postulates

    Variation, inheritance, overproduction, and differential survival and reproduction.
  • Genetic Variation

    Differences in DNA among individuals, leading to variation in traits.
  • What is an example of a trait affected by natural selection?

    Coat color in snowshoe hares, which affects their camouflage and survival rates.
  • How does natural selection lead to evolution?

    By increasing the frequency of traits that enhance survival and reproduction in a population.
  • What is the ultimate result of natural selection?

    Populations become better adapted to their environments over time.