[Campbell Biology P.548] According to the text, among the evolutionary mechanisms discussed ... | Practice Question

According to the text, among the evolutionary mechanisms discussed natural selection, genetic drift, gene flow , which one consistently leads to adaptive evolution?

  • A: Genetic drift, because it can increase the frequency of beneficial alleles.
  • B: Gene flow, as it introduces new advantageous alleles into a population.
  • C: Natural selection, because it is the only mechanism that consistently favors traits enhancing survival or reproduction.
  • D: All three mechanisms consistently lead to adaptive evolution if conditions are favorable.

Explanation

The text explicitly states: 'Natural selection is the only evolutionary mechanism that consistently leads to adaptive evolution.' While genetic drift and gene flow can influence allele frequencies, they do not consistently result in adaptations.