Question

In generation 0, the allele frequency A₁in a armadillos population is 0.4. Within each generation, 10% of individuals in that population are migrants from a different population with an allele frequency of 0.6.

1. In generation 1 and 2 (the next couple generations), Calculate the frequency of A₁

2. Is the change in allele frequency in generation 2 equal, less than, or greater to the change in generation 1? Explain your answer

3. After many generations in this population what will the allele frequency become?

4. What are some potential occurences or pressures that could happen on the population to counteract the impact of gene flow (name at least two)? Explain your answer.

Answer 1

1. let us consider a population of 100 people. so the number of migrants is 10

migration frequency m=10/100 =0.1

No. of A1alleles after migration = No. of A1 alleles from residents + No. of A1 alleles from migrants

= (Fraction of residents) (Population size) (Frequency of A1 allele in residents) + (Fraction of migrants) (Population size) (Frequency of A1 allele in migrants)

= (1 ? 0.1)(100)(0.4) + (0.1)(100)(0.6) = 36+6= 42

frequency of A1 alleles= 42/100= 0.42

2.for the next generation , the allele frequency will increase as we will consider the resident allele frequency as 0.42

(1 ? 0.1)(100)(0.42) + (0.1)(100)(0.6) = 37.8 + 6 =43.8

the sllele frequency will be 0.43,

Clearly the change is less than the change in the first generation.

3. The allele frequency will become miday between the allel frequencies of the residents and the migrants, that is 0.5, after that it will become stable and will be at equilibrium.

4.i) Natural selection

ii) geographical spaciation.