When alleles increase in frequency because they allow the organism to better survive and reproduce in its environment, this is a result of:
1. Natural selection
2. mutation
3. adaptation
4. gene flow

1. Natural selection

Explanation:

population. population is the number of people or animals in a particular place. an example of population is over eight million people living in new york city.

here is your answer hope i .

yes, because even though a theory has a  lot of evidence to support it, it is not always true