Living Environment Regents Practice Test

What role does variation play in natural selection?

1. It decreases competition among species

2. It is vital for adaptation and survival

3. It has no effect on evolutionary processes

4. It ensures identical traits in populations

The correct answer is: It is vital for adaptation and survival

Variation is crucial in natural selection as it provides the genetic diversity that a population needs to adapt to changing environments. When individuals within a species exhibit different traits, some may possess characteristics that make them better suited for survival and reproduction in their specific environment. These advantageous traits can be passed on to future generations, leading to a gradual change in the population over time, which is known as adaptation. Without variation, all individuals would have the same traits, and if the environment changed, the entire population could be at risk of extinction since none would be equipped to cope with the new conditions. Therefore, variation is essential for the evolutionary process, as it increases the likelihood that some individuals within a population will thrive despite environmental challenges, thus ensuring the survival of the species as a whole. The other options do not accurately reflect the role of variation in natural selection: decreasing competition does not relate to variation's role in adaptation; claiming variation has no effect ignores its fundamental importance in evolution; and ensuring identical traits would restrict adaptability, leading to vulnerability rather than resilience in populations.