Which of the following would best demonstrate that a given population has evolved?

• A. An increase in the population size due to abundant food resources.
• B. A change in the physical environment without any genetic change in the population.
• C. A measurable change in allele frequencies within the population over several generations.
• D. A temporary migration of individuals into the population.

Answer: (C)

Verified step by step guidance

1. Step 1: Understand the concept of evolution in biology. Evolution is defined as a change in the genetic composition of a population over time, often measured by changes in allele frequencies within the population.
2. Step 2: Analyze the options provided in the problem. Look for evidence of genetic change, as this is the hallmark of evolution. Population size changes, environmental changes without genetic shifts, or temporary migrations do not necessarily indicate evolution.
3. Step 3: Focus on the option mentioning 'a measurable change in allele frequencies within the population over several generations.' This aligns with the definition of evolution, as allele frequency changes are a direct indicator of genetic shifts in the population.
4. Step 4: Consider why the other options do not demonstrate evolution. For example, an increase in population size due to abundant food resources is an ecological change, not a genetic one. Similarly, a change in the physical environment without genetic change does not meet the criteria for evolution. Temporary migration affects population composition but does not necessarily alter allele frequencies over generations.
5. Step 5: Conclude that the best demonstration of evolution in this context is the measurable change in allele frequencies within the population over several generations, as it directly reflects genetic changes over time.