Can someone PLEASE explain how this makes sense DESPERATE Th

Can someone PLEASE explain how this makes sense. DESPERATE. The inputted genotype frequencies are NOT THE SAME as the ones calculated for in the second part. same generation and population. Why couldnt he just use F(AA)=p^2 TO BEGIN WITH? Then it would have returned ACCURATE genotype frequencies. PLEASE HELP I AM DESPERATE.

Guppies (Poecillia reticulata) are small, brightly colored fish that are common in freshwater streams in Trinidad. Imagine that the coloration is controlled by two alleles at a given gene. On a sampling trip, a young ecologist collects the following: 200 Brown guppies (AA) 600 Red guppies (Aa) 200 Yellow guppies (aa) Assuming HW equilibrium, calculate the allele & genotype frequencies of the population of guppies. 0.5 0.5 (0.5) fAA) a p 0.25 2 (0.5 0.5) 0.50 faa) q? 0.25

Solution

The Hardy-Weinberg equation is expressed as:

p² + 2pq + q² = 1

where p is the frequency of the \"A\" allele and q is the frequency of the \"a\" allele in the population. In the equation, p² represents the frequency of the homozygous genotype AA, q² represents the frequency of the homozygous genotype aa, and 2pq represents the frequency of the heterozygous genotype Aa. In addition, the sum of the allele frequencies for all the alleles at the locus must be 1, so p + q = 1. If the p and q allele frequencies are known, then the frequencies of the three genotypes may be calculated using the Hardy-Weinberg equation. In population genetics studies, the Hardy-Weinberg equation can be used to measure whether the observed genotype frequencies in a population differ from the frequencies predicted by the equation.

Here,in f(AA),the trait is dominant,so the allele frequency of f(A) is taken as p.Same as in case of recesssive trait f(aa);where the allele freuency of f(a) is taken as q.This elps in calculating f(Aa) by taking p and q as f(A) and f(a).