Disruptive selection events select for
a. common traits
b. genetic uniformity
c. camouflage traits
d. extreme traits
Please select the best answer from the choices provided
The Correct Answer and Explanation is:
The correct answer is d. extreme traits.
Explanation:
Disruptive selection is a type of natural selection where individuals at both extremes of a phenotypic range have higher fitness than individuals with intermediate traits. This form of selection can increase genetic diversity within a population by favoring individuals who display characteristics that are at the two extremes of a particular trait.
To understand disruptive selection in more detail, let’s break down the process:
- Extreme Traits: In disruptive selection, individuals with extreme phenotypes (traits that are far from the average) are more successful at surviving and reproducing. For example, in a population of birds with varying beak sizes, if food sources are either very large or very small, birds with exceptionally large or small beaks might be better at obtaining food than birds with medium-sized beaks, which cannot efficiently feed on either type.
- Intermediate Traits: Intermediate phenotypes are less favored in disruptive selection because these individuals are not as adapted to either extreme of the environmental pressures. Therefore, the intermediate traits are selected against.
- Resulting Evolutionary Shift: Over time, disruptive selection can lead to a split in the population into two distinct groups. If the pressure for extreme traits continues, the population may eventually diverge into two different species, each adapted to one of the extremes. This process can contribute to speciation, where new species evolve from a common ancestor.
- Contrast with Other Forms of Selection:
- Directional Selection: This favors one extreme phenotype, pushing the population’s trait distribution toward that extreme.
- Stabilizing Selection: This favors the average or intermediate phenotype, reducing variation within the population.
Disruptive selection plays a key role in maintaining diversity in a population and, in some cases, can lead to evolutionary change by favoring both extremes rather than a uniform or average trait.