How is directional selection related to evolution?

Answer 1

Directional evolution is where one allele is selected in a population over another allele. Imagine a certain breed of dog that live in cold weather, they will have genes for thick fur (allele A), they are still caring allele for thin fur (allele a), but its recessive and animals with thin fur often dont make it. So if you looked at a distrubition in a population of these animals you would see a preponderance for A alleles and very low level of a alleles. Now imagine that over time their habitat changed and they no longer need the thick fur, in fact its detrimental to the animal to have thick fur. You would see a allele distribution shift from most animals having genes A to genes a. Even if a is recessive to A, if all the animals with thick fur die out then only those with thin fur can survive.

Answer 2

well I'm not sure if this is right but in my book it say: the environment controls the direction taken by natural selection. When the environment changes different traits may become advantageous.

i found this in my bio book in chapter 11.6 but you should also check out 11.5 to

hope this helps

Answer 3

Directional selection is a type of natural selection that favors individuals with traits at one extreme of a phenotypic range, leading to a shift in the average phenotype of a population over time. Through this process, certain traits become more common in a population, which can ultimately drive evolutionary change by influencing the genetic makeup of future generations.