Question

for each generation, take 6 of the 10 alleles and give three to the deme on your left and three to the deme on your right. Conversely, add in three alleles from the deme on your left and three alleles from the deme on your right. Note that this requires that the entire class samples in unison.

Q8) How did the addition of gene flow affect genetic variation in your deme? Which model of gene flow (infinite island model or stepping stone) is most consistent with the pattern we simulated in class?

Answer 1

Gene flow or gene migration, in population genetics, is the transport of genetic changes from one population to another. Immigration or Emmigration in a population may causes in a change in allele frequencies, altering the genetic diversity distribution within the populations. Immigration causes in the addition of new alleles to the previous gene pool of a particular species. Increase gene flow rate can decrease the genetic distinction between the two groups, ectendin homogeneity.

Most local demes get immigrants from other demes, or from other source of large populations. Biologists call
the genes transfer across boundaries of population as gene flow. Gene flow is a strong influence in
maintaining demes variation, and reducing the demes differences.

Wright's Island model as well as Kimura's stepping stone model are typical classification for gene flow or migration to individuals among subpopulations.

In the Island model, all demes are interchanging migrants at a specific time, individuals migrate with m frequency, as seen in Wright's approximation for F_ST

F_ST=1/4Nm+1

In Kimura's stepping stone model, individuals can migrate to a neighbouring subpopulation only with m/2 frequency.

In the infinite island model, the infinite(if m≠0m≠0) migrants number. With demes d (or islands), the overall number of migrants is dNm where, m is known as the rate of migration among any two patches.

Under a model linear stepping stone model with single step (because there many complex stepping stones models exist) only, with d demes, then overall migrants number is dNm (minus small estimation for the world extremities) if m is explained as the rate of migration from one deme to next deme. Half of dNm are moving toward the left and half of them are moving toward the right.

for a set of population, allele frequency analysis releases wether the data missing an effect called isolation by distance (IBD) hence consistent with the island model and if the data display IBD are consistent with stepping stone model.