Final Answer:
Alleles that improve the _fitness_ may increase in frequency.
Step-by-step explanation:
In the realm of evolutionary biology, the term "fitness" encompasses an organism's ability to survive and reproduce in a given environment. Alleles are alternative forms of a gene, and their frequency in a population can change over time through the process of natural selection.
When an allele confers a fitness advantage, meaning it enhances an organism's ability to survive and reproduce, it is more likely to be passed on to subsequent generations. This is because individuals carrying the advantageous allele are more successful in leaving offspring that inherit the beneficial trait. As a result, the frequency of alleles that improve fitness tends to increase in a population over successive generations.
Natural selection plays a crucial role in shaping the genetic composition of populations. Individuals with alleles that contribute positively to their fitness have a higher chance of passing those alleles to their offspring. Over time, the prevalence of these advantageous alleles increases within the population, as they become more widespread through successful reproduction.
The mathematical underpinning of this process involves the concept of differential reproductive success. The reproductive success of individuals with advantageous alleles contributes to the overall increase in the frequency of those alleles within the gene pool. Therefore, alleles that improve fitness are more likely to become predominant, reflecting the dynamic interplay between genetics and natural selection in the evolutionary process.