Question

Adaptive radiation is an example for
A)Directional selection
B)Diversifying selection
C)Stabilizing selection
D)Sympatric speciation

Answer 1

Hint: The father of the evolution theory was Darwin. The observation of diverse species of finches within the island were among the events credited with stimulating Darwin’s interest in how species originate.

Complete answer:
Natural selection could be a process during which individual organisms which possess favorable traits have greater chances of surviving and reproduce. However, activity only acts on population’s heritable traits: selecting for beneficial alleles, thus, increasing their frequency within the population, while selecting against deleterious alleles and, thereby, decreasing their frequency adaptive evolution. This is the adaptation (by genetic mutation) of an organism which allows it to successfully spread into other environments. It will be opportunistic or forced through changes to natural habitats.

Adaptive radiation, evolution of an animal or plant group into a good style of types adapted to specialized modes of life. Adaptive radiations are exemplified in closely related groups that have evolved during a relatively short time. An example is Darwin’s finches.

Adaptive evolution in finches: Through action, a population of finches evolved into three separate species by adapting to many different selection pressures. Each of the three modern finches contains a beak adapted to its life history and diet.

There are some ways selection affects variation in a very population:
1.Stabilizing selection
2.Directional selection
3.Diversifying selection

1.Stabilizing Selection: When natural process favors a mean phenotype by selecting against extreme variation, the population undergoes stabilizing selection.

2.Directional Selection: When the environment changes, populations will often undergo directional selection, which selects for phenotypes at one end of the spectrum of existing variation.

3.Directional selection: Directional selection occurs when one phenotype is favored, causing the allele frequency to continuously shift in one direction.
Diversifying (or Disruptive) Selection: Sometimes natural processes can select for 2 or more distinct phenotypes that every have their advantages. In these cases, the intermediate phenotypes are often less fit than their extreme counterparts. Called diversifying or disruptive selection, this can be seen in many populations of animals that have multiple male
mating strategies, like lobsters. Diversifying selection also can occur when environmental changes favor individuals on either end of the phenotypic spectrum.

Hence, the correct answer is option (B)

Note: Urban environments, where ecosystems are different from rural environments, show genetic mutations in many plants moreover as animals. Serotonin transporter gene (SERT) mutations in urban birds reduce levels of hysteria. This can be not observable within the anatomy of birds, yet related to health- and survival-related traits with subsequent increase in reproduction, and so compliant with the laws of radiation.