0
votes
0answers
9 views

Effect of natural selection on the phenotypic variance. Empirical studies

Short background Theoretically speaking, natural selection causes a decrease in genetic variance and because the environmental variance should remain unchanged, natural selection causes a decrease of ...
3
votes
2answers
78 views

Heterozygosity under genetic drift

The wright-Fisher model of genetic drift is: $$p_{ij} = \binom{2N}{j}\left(\frac{i}{2N}\right)^j \left(1- \frac{i}{2N}\right)^{2N-j} $$ ,where $\binom{2N}{j}$ is a binomial coefficient. From this ...
3
votes
1answer
62 views

How does GC-content evolve?

Background GC-content refers to the frequency of base pairs that are either C or G in the genome, or in other words the number of GC base pairs divided by the addition of the number of GC base pairs ...
0
votes
2answers
46 views

DNA adaptation in human life

Does our DNA adapt by human lifetime? Or do we have the same genetic information from birth to death? I mean: What is usually called "evolution" means "natural selection" like this: ...
1
vote
1answer
21 views

Could mating/recombination be responsible for evolution of entirely novel features?

The diploid chromosomal architecture is rather interesting. For example, because of diploidy we Humans have to mate. Of course in that sense, because diploid organisms often have mate, this has led to ...
4
votes
1answer
98 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 ...
4
votes
1answer
143 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 ...
1
vote
1answer
23 views

What indices can we use to describe fitness landscapes?

We usually talk of smooth or rugged fitness landscape. Are there any (standard) indices to measure the "structure" of fitness landscapes? For example, one might consider the mean epistatic ...
4
votes
3answers
99 views

Fisher's Fundamental Theorem of Natural Selection

Ronald Fisher discovered what he, with humility, called the Fundamental Theorem of Natural Selection. This theorem says (in its modern terminology): The rate of increase in the mean fitness of any ...
6
votes
0answers
132 views

Correlation between genome size and mutation rate?

Martin Nowak in his book "Evolutionary Dynamics" talks about a given correlation between genome size and mutation rate. What correlation does exactly exist between these two concepts? Is it a ...
3
votes
3answers
150 views

Is there variation of AT/CG ratio along species?

Chargaff's rules say that the number of Adenine of the number of Thymine in a genome are equal (nA=nT) and similarly nC=nG. This makes obvious sense knowing that C binds to G and A to T. But what ...
1
vote
2answers
153 views

Eusociality and Natural selection?

Eusociality, particularly focusing on the presence of certain altruistic sterile organisms within the social set-up creates questions as to why would the process of natural selection have favoured the ...
3
votes
1answer
76 views

Low complexity region and relaxed selection

I'm reading a text (Wagner, 2007) on identifying positive selection. In paper, the author says that low complexity regions are known to be associated with relaxed selection. I'm trying to understand ...
4
votes
0answers
63 views

effect of background selection on promoter regions compared to distant enhancers?

Has anyone looked at the effect of background selection on the levels of conservation of promoter regions compared to distant enhancers? Do promoter regions have a higher conservation due to ...