Question

1. Suppose a rising sea level leads to the splitting of one Pacific island into two smaller islands. A population of geckos on this island is thus split into two small populations. An evolutionary biologist interested in studying the effect of this split performs an analysis of a polymorphic single nucleotide located in an intron of the alpha-tubulin gene. Immediately after the split, the two populations start at different frequencies for a 'T' allele. Population 1 has a frequency of the 'T' allele starting at 0.9. Population 2 has a frequency of the 'T' allele starting at 0.1 Assuming that the allele is neutral, what is the most likely outcome?

   		After many generations, Population 1 fixes for the 'T' allele and Population 2 loses the 'T' allele.
   		After many generations, both populations converge on a 0.5 frequency and remain that way.
   		After many generations, Population 1 remains at precisely 0.9 and Population 2 remains at precisely 0.1 for the frequency of the 'T' allele.
   		After many generations, the 'T' allele fixes in both populations.

Answer 1

Given Information:- In the above situation, Geographical isolation occurs in a population og Geckos and resulted in splitting it into two subpopulation having different allelic frequencies for allele 'A' at separation time.

Now the question is what would be the most likely outcome after several generation from given options.

Anyone outcome among these options is not 100% correct. All outcomes have chances to appear after several generation.

Explanation:- All depend upon the natural selection process according to the concept  "Origin of Species".

Cosidering the following cases:-

CASE I - If genetic drift occur in one population leading to the loss of 'T' allele from this population then, option first is most likely to occur after many generations, Population 1 fixes for the 'T' allele and Population 2 loses the 'T' allele.

CASE II - If genetic flow continue somehow between the two subpopulation even after splitting of polulation, then according to Hardy-Weinberg assumptions, Finally both population will reach at genetic equilibrium and option second is most likely to occur after many generation, both populations converge on a 0.5 frequency and remain that way.

CASE III - If no any population will favoured by any of natural selection process and present situation equally affect both population, then third option will more likely to occur after many generation. Population 1 remains at precisely 0.9 and Population 2 remains at precisely 0.1 for the frequency of the 'T' allele.

CASE IV - If genetic adaptation occurs for allele 'T' as a need for survival because this allele is somehow mandatory for maintaining their life, then in both popualtion as a part of evolution the 'T' allele fixes in both populations after several generation.