Evolution Review

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What is gene flow?

Back

Gene flow is the movement of genetic material (alleles) between populations, which can occur through migration of individuals or gametes (e.g., pollen).

Front

What gas was absent in ancient Earth?

Back

Oxygen was not present in significant amounts in ancient Earth, which was primarily composed of gases like carbon dioxide, ammonia, and methane.

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What is stabilizing selection?

Back

Stabilizing selection is a type of natural selection that favors average individuals in a population, reducing variation and maintaining the status quo for a particular trait.

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How does gene flow affect populations?

Back

Gene flow can increase genetic diversity within a population and reduce differences between populations, potentially leading to greater adaptability.

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What is directional selection?

Back

Directional selection is a type of natural selection that favors one extreme phenotype over others, causing a shift in the population's trait distribution.

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What is genetic drift?

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Genetic drift is a random process that can cause allele frequencies to change over time, especially in small populations, leading to a loss of genetic variation.

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What is the significance of the peppered moth example?

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The peppered moth example illustrates natural selection, where dark moths became more common in polluted areas due to better camouflage against predators.

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What is the role of selection pressure?

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Selection pressure refers to environmental factors that influence which individuals survive and reproduce, shaping the evolution of species.

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What is diversifying (disruptive) selection?

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Diversifying selection is a type of natural selection that favors extreme phenotypes at both ends of the spectrum, leading to increased variation within a population.

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How does a population's size affect genetic drift?

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In smaller populations, genetic drift has a more pronounced effect, leading to greater fluctuations in allele frequencies and potential loss of genetic diversity.