Evolution & Natural Selection Flashcard

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What is a vestigial structure?

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A vestigial structure is a body part that has lost its original function through the course of evolution. An example in humans is the appendix.

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What is natural selection?

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Natural selection is the process by which organisms better adapted to their environment tend to survive and produce more offspring.

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What is evolution?

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Evolution is the change in the heritable characteristics of biological populations over successive generations.

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What does it mean when we say all living organisms descended from a common ancestor?

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It means that all species share a common lineage and have evolved from a single ancestral species.

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What is directional selection?

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Directional selection is a type of natural selection that favors one extreme phenotype over the other, leading to a shift in the population's traits.

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What is stabilizing selection?

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Stabilizing selection is a type of natural selection that favors average phenotypes and reduces variation in a trait.

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What is disruptive selection?

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Disruptive selection is a type of natural selection that favors extreme phenotypes at both ends of the spectrum, leading to two or more contrasting phenotypes.

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What is mutation in the context of evolution?

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Mutation is a change in the DNA sequence that can introduce new genetic material into a population, potentially leading to new traits.

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What is genetic drift?

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Genetic drift is a mechanism of evolution that refers to random changes in the frequency of alleles in a population, often having a more significant effect in small populations.

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What is the significance of phenotypic variation?

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Phenotypic variation is important for natural selection as it provides the raw material for evolution, allowing populations to adapt to changing environments.