Question

You and your entomologist friend (after a successful butterfly collaboration) decide to work together on locust mating (what can you say, insects are awesome!). You investigate an African population of locusts that seems to sort assortatively but not totally. You observed 2 main genotypes tied to sound production for mating: high chirp (dominant) and low chirp (recessive) controlled by the locus CHIRP. You score the mating calls for your population locusts and find that 27% are low chirpers. You also observed that out of 100 locust, 62% seem to mate based on similar mating call. Calculate the heterozygosity for the next generation for this population of locusts.

Answer 1

Let the dominant allele be A and recessive allele be a.

Genotypes AA and Aa are high chirpers and aa are low chirpers.

According to Hardy-Weinberg equilibrium,

p - frequency of dominant allele

q - frequency of recessive allele

p²is the frequency of homozygous dominant, 2pq of heterozygous and q²of homozygous recessive.

Frequency of low chirpers (aa)

Frequency of recessive allele

Frequency of dominant allele

Only 62% of the matings happen with similar individuals. That means 38% mate with different indviduals.

The frequency of alleles in the next generation:

Therefore, heterozygosity in the next generation

So, heterozygosity in the next generation is 50%.