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

  • Thread starter Thread starter Big-Daddy
  • Start date Start date
AI Thread Summary
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.
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.
 

Thread 'Body dysmorphic disorder (BDD)'

https://www.nhs.uk/mental-health/conditions/body-dysmorphia/ Most people have some mild apprehension about their body, such as one thinks their nose is too big, hair too straight or curvy. At the extreme, cases such as this, are difficult to completely understand. https://www.msn.com/en-ca/health/other/why-would-someone-want-to-amputate-healthy-limbs/ar-AA1MrQK7?ocid=msedgntp&cvid=68ce4014b1fe4953b0b4bd22ef471ab9&ei=78 they feel like they're an amputee in the body of a regular person "For...
View full post »
Thread 'Did they discover another descendant of homo erectus?'

Thread 'Did they discover another descendant of homo erectus?'

The study provides critical new insights into the African Humid Period, a time between 14,500 and 5,000 years ago when the Sahara desert was a green savanna, rich in water bodies that facilitated human habitation and the spread of pastoralism. Later aridification turned this region into the world's largest desert. Due to the extreme aridity of the region today, DNA preservation is poor, making this pioneering ancient DNA study all the more significant. Genomic analyses reveal that the...
View full post »

Similar threads

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

Hot Threads

Recent Insights

Back
Top