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

  • Thread starter Thread starter Big-Daddy
  • Start date Start date
Click For Summary
SUMMARY

The discussion centers on the impact of monohybrid mating on allele frequency in a population. The original frequency of genotypes is denoted as f0, while the frequency after mating is denoted as f1. The calculations provided demonstrate that the frequency of the dominant allele (P(Dom)) and the recessive allele (P(Rec)) changes due to mating interactions, specifically highlighting the importance of combinatorial factors in these calculations. The participants confirm that the mating probabilities must include a factor of 2 for heterozygous interactions, ensuring accurate allele frequency predictions.

PREREQUISITES
  • Understanding of monohybrid inheritance
  • Familiarity with allele frequency calculations
  • Knowledge of genotype notation (e.g., Dom-Dom, Dom-Rec)
  • Basic principles of probability in genetics
NEXT STEPS
  • Study the Hardy-Weinberg equilibrium to understand allele frequency stability
  • Explore advanced population genetics models, such as Wright-Fisher and Moran models
  • Learn about the effects of selection and genetic drift on allele frequencies
  • Investigate the role of mating systems in evolutionary biology
USEFUL FOR

Geneticists, evolutionary biologists, and students studying population genetics will benefit from this discussion, particularly those interested in allele frequency dynamics and monohybrid mating effects.

Big-Daddy
Messages
333
Reaction score
1
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?
 
Biology news on Phys.org
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.
 

Similar threads

Hardy-Weinberg: Understand Allele Frequencies & Genotype Freqs.
  • · Replies 12 ·
Replies
12
Views
4K
Emery-Dreifuss Muscular Dystrophy
  • · Replies 1 ·
Replies
1
Views
2K
The correct way to calculate allelic frequencies?
  • · Replies 2 ·
Replies
2
Views
2K
Allele frequencies of the next generation
  • · Replies 9 ·
Replies
9
Views
3K
Hardy Weinberg Principle: Calculating Allele Frequency in a Fish Population
  • · Replies 3 ·
Replies
3
Views
3K
Biology Genetics Problem -- six independently assorting genes in a plant
  • · Replies 6 ·
Replies
6
Views
5K
Biology - Frequency of allele problem
  • · Replies 4 ·
Replies
4
Views
6K
Biology Genetics- how many of each genotype?
  • · Replies 1 ·
Replies
1
Views
4K
Graduate Zeroth law of black hole thermodynamics
  • · Replies 9 ·
Replies
9
Views
1K
Frequency shift of emitted photon due to recoil
  • · Replies 2 ·
Replies
2
Views
6K