Question

How would you explain the existence of higher or lower mutating strains within a species?

Answer 1

The frequency of occurrence of new mutations in a gene of an organism over a period of time is known as mutation rate. The existence of different types of mutations, or for that matter different types of mutating strains within a species is due to the fact that mutation rates are not fixed/constant and there is not limitation to the type of mutation that can occur.

In a population of a species, there can be found lower mutating strains as well as higher mutating strains. Mutation rate of any organism is considered to be an evolved characteristic. They are influenced by the environment as well as the genetics of the individual. Even in the genome of a single organism, some sites accumulate more mutation than other. This is precisely the reason why some humans are more prone to cancer than others.

It should be noted that a new mutation often creates a new allele for a specific gene, thus changing the allele frequency in a given population. The new mutations are then acted upon by natural selection, because of which unfavorable mutations are often eliminated from the population, while retaining the favorable ones.