Which of these statements best defines speciation?

• A. The movement of individuals from one population to another, resulting in gene flow.
• B. The gradual change in allele frequencies within a single population over time.
• C. The process by which one species splits into two or more distinct species.
• D. The extinction of a species due to environmental changes.

Answer: (C)

Verified step by step guidance

1. Step 1: Begin by understanding the concept of speciation. Speciation is the evolutionary process by which populations evolve to become distinct species. It typically involves genetic divergence and reproductive isolation.
2. Step 2: Analyze each statement provided in the problem. For example, the movement of individuals between populations (gene flow) does not define speciation, as it typically prevents populations from diverging into separate species.
3. Step 3: Evaluate the gradual change in allele frequencies within a single population over time. This describes microevolution, not speciation, as it does not necessarily lead to the formation of new species.
4. Step 4: Consider the extinction of a species due to environmental changes. Extinction is the loss of a species, not the formation of new ones, so this does not define speciation.
5. Step 5: Identify the correct definition of speciation: 'The process by which one species splits into two or more distinct species.' This involves mechanisms such as allopatric speciation (geographic isolation) or sympatric speciation (reproductive isolation without geographic barriers).