Question

Random genetic drift in a population probably results from
(a)High genetically variable individual
(b)Interbreeding within the population
(c)Constant low mutation rate
(d)Large population size

Answer 1

Hint: The random change in the frequency of alleles in a population over successive generations in the gametes. Each new generation differs from its parental generation concerning allele frequencies simply because of random variation in the distribution of gametes.

Complete answer:
In a population, when the change in the frequency of an existing gene variant (allele) occurs due to random sampling of organisms is called the genetic drift which is also known as allelic drift. Genetic variation is reduced as genetic drift may cause gene variants to disappear completely and thereby and also can cause initially rare alleles to become much more frequent and even fixed.
The genetic drift is mainly concerned with the gene frequency of a reproducing small population and in a small population not all the alleles which are representatives of that species may be present. A chance event may increase the frequency of a character in a small population that has little adaptive value. Thus, in the origin of new species on islands, the genetic drift may play a significant role and other isolated populations which results in the development of a small population as a whole with different characters from those found in the main population, and such deviations may even lead to speciation or formation of a new species. The development of the new species can be caused by the interbreeding of the population.

Additional Information: 1) A scientist who also explained natural selection using Mendelian genetics, Ronald Fisher held the view that genetic drift plays at the most a minor role in evolution, and this remained the dominant view for several decades.
2) Motoo Kimura, A population geneticist reanalyzed in 1968 with his neutral theory of molecular evolution, which claims that genetic drift causes the most instances where a genetic change spreads across a population by acting on neutral mutations.
3) The role of random chance in evolution in 1921 was first outlined by Arend L. Hagedoorn and A. C. Hagedoorn-Vorstheuvel La BrandHagedoorn and highlighted that random survival plays a key role in the loss of variation from populations.
4) The role of genetic drift criticized by two scientists, John H. Gillespie and William B. Provine through sampling error in evolution and also argue that selection on linked sites is a more important stochastic force.
So, the correct answer is, ‘Interbreeding within the population’.

Note: The effect of genetic drift is larger when there are few copies of an allele, and when there are many copies the effect is smaller. A new allelic variation is created by mutation slowly in DNA and proteins, and genetic drift slowly eliminates this variability, thereby achieving a steady state.