All Questions
13 questions
0
votes
1
answer
106
views
Can a trait be too successful? Wouldn't overwhelmingly successful traits limit variability, which is one of the requirements of NS? [closed]
Can a trait be too successful? Wouldn't an overwhelmingly successful trait soon limit the gene pool, and if so, how would the process of natural selection react to that? If an individual is born ...
- 1
0
votes
1
answer
791
views
Why is selection less effective in small populations than in larger?
I can understand that the genetic drift has a higher impact on smaller populations, but what does it mean for the selection to be less effective in small populations than higher?
- 155
1
vote
0
answers
37
views
Finding intensity of selection against dominant homozygotes
I was looking at some Olympiad questions and came across the following:
If the frequency of a completely recessive allele is $0.2$ and it remains unchanged from generation to generation due to ...
- 111
1
vote
1
answer
128
views
Balancing selection vs introgression? [closed]
Balancing selection can maintain polymorphisms in natural populations for extended periods of evolutionary time. However, in this paper, Dannemann et al. 2016 identify three archaic haplotypes in the ...
- 19
5
votes
1
answer
168
views
How frequent are selective sweeps?
Introduction
Selective sweep is the most famous genetic signature of selection. We know of a number of classical examples of selective sweeps, some of them in humans. See the classical example of the ...
- 68.3k
0
votes
1
answer
119
views
About lack of selective pressure
In [1] it is stated that:
the frequency of comutations in FGFR3 and KRAS or PIK3CA and KRAS was lower than predicted by chance, suggesting ... a lack of selective pressure for both mutations to ...
- 820
1
vote
0
answers
710
views
Can the value of heritability be greater than 1?
Heritability defined as genetic variance divided by total variance seems to be bounded between 0 and 1. However, I see a way of calculating heritability on this page (http://www.radford.edu/~rsheehy/...
- 466
4
votes
2
answers
982
views
How to distinguish between a genetic bottleneck and directional selection?
Genetic bottlenecks and directional selection should have relatively similar genetic signals: reduced heterozygosity and greater genetic divergence (Fst?) in contemporary populations compared to the ...
7
votes
1
answer
607
views
How to determine whether changes of an allele's frequency are due to genetic drift or selection?
Given that both natural/artifical selection and genetic drift are evolutionary mechanisms that influence how allele frequencies shift in a population:
Are there ways to determine whether a frequency ...
- 173
2
votes
1
answer
560
views
What is a typical value of the selection coefficient s?
I am trying to gain an understanding of the real world effects of natural selection from the equations, especially comparing it with drift. However I have been unable to find any examples which give ...
- 2,979
1
vote
1
answer
126
views
Fst Differences Between Mature Trees and Seeds
For a single co-dominant locus in two populations of blue oak, I am given genotype frequency data (genotypes are AA, AB, BB) for adult trees (at least 150 years old) in both populations (pop 1 and pop ...
5
votes
1
answer
4k
views
How do I calculate the change in allele frequency in a haploid population under selection?
From this book
For simplicity, let us consider a haploid organism and assume that the frequencies of alleles $A_1$ and $A_2$ are given by $x$ and $y=1-x$, respectively. We also assume that the ...
- 68.3k
7
votes
1
answer
2k
views
Why does the slope of parent-offspring regression equals the heritability in the narrow sense?
Background
---- Notations and assumptions ----
let $W_{ij}$ be the fitness associated to the genotype $AiAj$. $x$ is the frequency of the allele $A1$ in the population. The frequency of the allele $...
- 68.3k