Question

The process of speciation takes place due to
A. Founder effect
B. Heterozygote advantage
C. Population bottleneck
D. Random mating
E. Reproductive isolation

Answer 1

Hint: The process of formation of a new species from the pre-existing species is commonly called speciation. Such newly developed species has its own unique characteristics, while some characteristics also resemble that of pre-existing species. Speciation usually occurs during the course of evolution.

Complete answer:
Founder effect is described as the phenomenon occurring due to isolation of a small group of individuals from a larger population. In this, the individuals in a small group do not resemble the individuals of the larger population. Rather the individuals would only resemble the ones in their smaller group, regardless of their looks.
Heterozygote advantage is referred to as the advantage posed due to presence of two mismatched alleles of a gene. This helps prevent any chance of getting affected with the presence of one defective allele in a gene. It is normally advantageous in case of diseases, and as a result, the carriers do not often get affected leading to a normal life.
Population bottleneck is a type of genetic drift that eventually leads to drastic decrease in size of a population. It can be caused by different events including hunting of a population upto a point that leads to extinction of the population/species, destruction of their habitats, environmental disaster, and others.
Random mating is the breeding that occurs between individuals of a population in proportion to their genetic frequencies. It helps intermixing of the genetic constituents existing in a respective population. As a result, the genetic and phenotypic characters remain conserved upto certain limits.
A collection of mechanisms, physiological processes and behaviours that ensure any offspring produced isn’t fertile, or prevent members of two different species to mate for producing offspring is normally termed as reproductive isolation. Speciation occurs as a byproduct of genetic changes, which accumulated between two populations that were previously interbreeding and belonged to the same species.

Therefore, speciation often takes place during evolution due to reproductive isolation.

Note: Unlike reproductive isolation, other events including Founder effect, heterozygote advantage, population bottleneck, random mating do not result in formation of a new species. However, these events are significantly important for incorporation of genotypic and phenotypic variations in a population.