Natural selection leads to the directional change when
1. More individuals acquire mean character value in the distribution curve
2. More individuals acquire peripheral character value of both ends of distribution curve
3. More individuals acquire value other than the mean character value at any one end of distribution curve
4. No individual acquires the peripheral character value
choose correct option..
Answers
The answer is option 3.
Explanation:
1. Natural selection is a process in which individual organisms or phenotypes that possess favorable traits are more likely to survive and reproduce.
2. When the environment changes, populations will often undergo directional selection, which selects for phenotypes at one end of the spectrum of existing variation.
3. A classic example of this type of selection is the evolution of the peppered moth in eighteenth- and nineteenth-century England. Prior to the Industrial Revolution, the moths were predominately light in color, which allowed them to blend in with the light-colored trees and lichens in their environment. As soot began spewing from factories, the trees darkened and the light-colored moths became easier for predatory birds to spot.
4. Over time, the frequency of the melanic form of the moth increased because their darker coloration provided camouflage against the sooty tree; they had a higher survival rate in habitats affected by air pollution. Similarly, the hypothetical mouse population may evolve to take on a different coloration if their forest floor habitat changed. The result of this type of selection is a shift in the population’s genetic variance toward the new, fit phenotype.