What is natural selection?

What is natural selection?

• A. Differential survival and reproduction of individuals due to heritable variations, changing allele frequencies over time.
• B. Random mating patterns
• C. A mutation that creates new traits instantly
• D. Gene flow among populations

Answer: (A)

Natural selection is the differential survival and reproduction of individuals due to heritable variations, causing allele frequencies to change over generations. In a population, individuals vary in traits that are passed down to offspring. The environment favors certain traits, so individuals with those traits tend to survive longer and produce more offspring. Those advantageous genes become more common in the population over time, leading to adaptation to the environment. This process requires variation, heritability, and more offspring for those with beneficial traits, with changes accumulating across generations. Random mating by itself doesn’t favor some traits over others, so it doesn’t systematically increase helpful alleles. A new trait arising from a mutation isn’t automatically increased in the population by itself; natural selection acts on existing variation and gradually increases the frequency of beneficial variants. Gene flow, the movement of alleles between populations, changes genetic makeup through migration rather than via differential survival and reproduction within a single population.

Natural selection is the differential survival and reproduction of individuals due to heritable variations, causing allele frequencies to change over generations. In a population, individuals vary in traits that are passed down to offspring. The environment favors certain traits, so individuals with those traits tend to survive longer and produce more offspring. Those advantageous genes become more common in the population over time, leading to adaptation to the environment. This process requires variation, heritability, and more offspring for those with beneficial traits, with changes accumulating across generations.

Random mating by itself doesn’t favor some traits over others, so it doesn’t systematically increase helpful alleles. A new trait arising from a mutation isn’t automatically increased in the population by itself; natural selection acts on existing variation and gradually increases the frequency of beneficial variants. Gene flow, the movement of alleles between populations, changes genetic makeup through migration rather than via differential survival and reproduction within a single population.