Which of these is not a step in natural selection? variation underpopulation struggle for existence survival of the fittest

To determine which option is not a step in natural selection, let's analyze each option in the context of Darwin's theory of natural selection:

1. Variation: This step is essential as it refers to the differences that exist within a species. Variation among individuals is critical for natural selection to occur.

2. Overpopulation: This concept indicates that more individuals are born than can survive, leading to competition for resources, which is a fundamental part of natural selection.

3. Struggle for Existence: This refers to the competition among individuals for survival and reproduction. It emphasizes that individuals must compete for limited resources, which is a key aspect of natural selection.

4. Survival of the Fittest: This phrase describes the process by which individuals with advantageous traits are more likely to survive and reproduce. It is often associated with natural selection, but it's more of a summary of the outcomes of the process rather than a specific step in itself.

Conclusion:

The term "survival of the fittest" is not a step in natural selection; rather, it describes the outcome of the process. Therefore, the correct answer is "survival of the fittest."