What are the different ways in which individuals with a particular trait may increase in a population?

Explanation

Different ways in which individuals with a particular trait may increase in population are variation, natural selection and genetic drift.
Variation: Variation is defined as the occurrence of differences among the individuals. No two individuals are exactly alike. Variations arising during the process of reproduction can be inherited and lead to increased survival of the individuals.
Natural selection: It results in adaptations in population to fit their environment better. Thus, natural selection directs evolution in the population of a particular species.
Genetic drift: The change in the frequency of certain genes in a population over generations is called genetic drift.