Variation in a species population provides several advantages, including:

- Increased adaptability to changing environments

- Greater resistance to diseases and parasites

- Ability to occupy a wider range of ecological niches

- Increased potential for evolution and survival

Option D is correct because individuals with varying traits are more likely to be better adapted to changes in their environment, such as climate change, predators, or competitors.

The other options are not directly related to the advantages of variation:

A. Dominance of individuals with favored traits is a result of natural selection, but not the primary advantage of variation.

B. Reaching reproductive age is not directly related to variation.

C. Recognition by mates may be influenced by variation, but it's not the primary advantage.