In the context of natural selection, which phrase best completes the definition: "Natural selection is the process by which evolution occurs; ______"?

• A. it occurs when organisms acquire traits during their lifetime and pass them to offspring
• B. it is the random change in allele frequencies due to chance events in small populations
• C. it results in differential survival and reproduction of individuals with heritable traits
• D. it is the movement of alleles between populations through immigration or emigration

Answer: (C)

Verified step by step guidance

1. Understand that natural selection is a mechanism of evolution that depends on variation in heritable traits within a population.
2. Recognize that natural selection leads to differences in survival and reproduction among individuals based on those heritable traits.
3. Eliminate options that describe other evolutionary processes: acquired traits passed to offspring (Lamarckism), random changes in allele frequencies (genetic drift), and movement of alleles between populations (gene flow).
4. Focus on the phrase that highlights the key outcome of natural selection: differential survival and reproduction of individuals with heritable traits.
5. Conclude that the best completion of the definition is the phrase emphasizing that natural selection results in differential survival and reproduction of individuals with heritable traits.