Which of the following is NOT one of the three primary methods used to determine population size in ecology?

• A. Observation
• B. Radioactive dating
• C. Sampling
• D. Mark and recapture

Answer: (B)

Verified step by step guidance

1. Step 1: Begin by understanding the context of the question. In ecology, determining population size is a fundamental task, and there are specific methods commonly used for this purpose. These methods are designed to estimate the number of individuals in a population effectively.
2. Step 2: Review the three primary methods mentioned in the question: Observation, Sampling, and Mark and Recapture. Each of these methods has distinct characteristics and applications in population studies. For example, Observation involves directly counting individuals, Sampling uses subsets of the population to estimate the total, and Mark and Recapture involves tagging individuals and tracking their recapture rates.
3. Step 3: Analyze the fourth option, Radioactive dating. This technique is primarily used to determine the age of fossils or geological samples by measuring radioactive decay, not to estimate population size. It is unrelated to the methods used in population ecology.
4. Step 4: Compare the purpose of Radioactive dating with the other three methods. Since Radioactive dating does not contribute to estimating population size, it is the correct answer to the question as the method that is NOT used for this purpose.
5. Step 5: Conclude that the correct answer is Radioactive dating, as it is not one of the three primary methods used to determine population size in ecology.