Question

Which type of selection tends to increase genetic variation?

Answer 1

Negative frequency-dependent selection and diversifying selection are types of natural selection that tend to increase genetic variation within a population by favoring rare or distinct phenotypes.

Step-by-step explanation:

Among the different types of natural selection, negative frequency-dependent selection and diversifying selection are known to increase genetic variation within a population. Negative frequency-dependent selection promotes the survival of rarer phenotypes, thus adding to the population's genetic divergence. On the other hand, diversifying selection favors multiple distinct phenotypes, especially when environmental conditions provide advantages to individuals with extreme traits at both ends of the spectrum, rather than intermediate phenotypes. This results in a broadening of the population's genetic diversity. Sexual selection can also contribute to genetic variance, particularly through the evolution of distinct male and female forms known as sexual dimorphism.

Answer 2

Disruptive selection

Step-by-step explanation:

In disruptive selection individual with traits having the extreme values are selected over the individuals having intermediate trait values. This increases the genetic variance because the variance of trait increases and the population gets divided into two separate groups.

For example, there is a population of moth in an area in which trees with black color bark and white color bark are present and the genotype BB gives rise to black color moth and bb give rise to white color moth but genotype Bb which is intermediate trait give rise to blue color moth.

So, in this case, white and black color moth can camouflage on tree having white color bark and black color bark but the blue color moth will not be able to camouflage so it will be hunted more by predators which is an example of disruptive selection.