Does monohybrid mating affect the frequency of alleles in a population?

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The discussion centers on the changes in allele frequencies following monohybrid mating. The original frequency of genotypes is denoted as f0, while the frequency after mating is f1. The calculations presented suggest that the frequency of the dominant allele (P(Dom)) and the recessive allele (P(Rec)) should change due to mating. The initial formula for f1(Dom-Dom) is critiqued for missing a factor of 2, which accounts for the combinatorial probabilities of different genotype pairings during mating. This factor is essential for accurately calculating the probabilities of homozygous dominant and heterozygous matings. The discussion confirms that any mating between individuals with different genotypes requires this multiplying factor for accurate probability assessment.
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It would seem to me that after monohybrid mating, the frequency of the dominant and recessive allele should change? I will donate original frequency (i.e. proportion) by f0 and that after mating by f1.

f1(Dom-Dom) = f0(Dom-Dom)2 + 1/2 * f0(Dom-Dom) * f0(Dom-Rec) + 1/4 * f0(Dom-Rec)2

Am I right so far? (I hope my notation is intelligible - f0(Genotype) is the fraction of the genotype, in the original population.)

Then we can replace the terms to find f1(Dom-Dom) = P(Dom)4 + 1/2 * P(Dom)2 * 2*P(Dom)*(1-P(Dom)) + 1/4 * (2*P(Dom)*(1-P(Dom)))2 = P(Dom)4 - P(Dom)3 + P(Dom)2.

Where P(Dom) is the frequency of the dominant allele and P(Rec) is the frequency of the recessive allele, P(Dom)+P(Rec)=1, in the original population. Thus it would seem that the frequency of the allele has changed due to the mating?
 
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Big-Daddy said:
It would seem to me that after monohybrid mating, the frequency of the dominant and recessive allele should change? I will donate original frequency (i.e. proportion) by f0 and that after mating by f1.

f1(Dom-Dom) = f0(Dom-Dom)2 + 1/2 * f0(Dom-Dom) * f0(Dom-Rec) + 1/4 * f0(Dom-Rec)2

You forgot a factor of 2 in the fraction of Dom-Dom/Dom-rec matings to account for the combinatorics [i.e. the probability of a homozygous dominant individual mating with a heterozygote is 2*f(Dom-Dom)*f(Dom-rec)].
 
Ygggdrasil said:
You forgot a factor of 2 in the fraction of Dom-Dom/Dom-rec matings to account for the combinatorics [i.e. the probability of a homozygous dominant individual mating with a heterozygote is 2*f(Dom-Dom)*f(Dom-rec)].

Ah I see. And any mating between two individuals with different genotypes would also have this multiplying factor of 2 in the calculation of its probability?
 
Big-Daddy said:
Ah I see. And any mating between two individuals with different genotypes would also have this multiplying factor of 2 in the calculation of its probability?

Yes.
 

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