Questions related to the study of the distributions and changes of allele frequency in a population.

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What factors make a sequence evolve non-randomly?

On the wikipedia page about Fay and Wu's H, it talks about a non-randomly evolving sequence may be due to some selection acting or a selective sweep or population expanding/contracting. My questions ...
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24 views

Confusion over equations for population's heterozygosity vs. heterozygous individuals

On page 24 of Gillespie's Population Genetics, 2nd ed, an equation for $H$, the probability that two randomly drawn alleles are different by state, is given. $H$ is stated to be similar to the ...
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30 views

Is it possible to have a random un-mutation of genes?

According to this article: Gene mutations can be classified in two major ways: Hereditary mutations are inherited from a parent and are present throughout a person’s life in virtually ...
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43 views

ExAC Browser: What does a “dubious variant annotation” actually mean? [closed]

I wonder how a "dubious" variant annotation is exactly defined in ExAC. I couldn't find any further information neither at the variant's page nor in the FAQs. Link to ExAC browser. Link to variant ...
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40 views

Why was the study of “Concordance of Monozygotic and Dizygotic twins for traits” designed in this way? [closed]

I am confused by the twin study 'Concordance of Monozygotic and Dizygotic twins for traits.' My questions arose from 3:17-4:17 of the video And this is the related data I have referred I have ...
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21 views

Hybridization of an Indo-Aryan ethnic group and a Tibeto-Burmese ethnic group

The state in which I reside houses these two distinct ethnic groups. Physical Traits of the Indo-Aryan group Height:Medium Eyes:does not posses epicanthic fold Nasal bones:is not flat and broad ...
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1answer
76 views

How do heredity and regression to the mean work with respect to intelligence?

I am trying to understand the heredity of intelligence between generations in general, and how regression to the mean works in detail in particular. The answer I'm looking for should preferably answer ...
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30 views

How do I know if the tRNA gene is under purifying selection from looking at a sequence dataset?

I'm having trouble figuring out how to tell if a tRNA gene is under purifying selection, just by looking at its sequence dataset. Such as this one:
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29 views

What empirical evidence of genetic assimilation is there?

There have been many articles arguing that we should view the phenotype in the center of evolutionary theory rather than the genotype as done in most population (or quantitative) genetics. A typical ...
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27 views

What is the effective population size of a simple two deme metapopulation?

I am confused as to how to compute the effective population size $N_e$ of a theoretical structured population. Let's consider here a simple case study. Imagine a 2-deme metapopulation. Each deme is ...
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68 views

Are heterozygotes always fitter than homozygotes? Can inbreeding be beneficial?

Inbreeding is mostly not very good because when there is a 'disease' in one allele, the other could/would take over the function. But when you have two of the same genes/alleles, do they, or could ...
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15 views

Difference in associated SNPs in GWAS

I noticed that when GWAS studies are being replicated, some SNPs near a gene known to cause a trait are enriched in frequency in those with the trait. However, among the different studies, the most ...
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1answer
28 views

How are the dominance and additive effects reflected in the mean and variance of the offsprings of two individuals with known phenotype?

If I estimated the genetic additive σ2A, genetic dominance σ2D and environmental effect σ2E of a trait in a population, what will be the predicted value of the offsprings of two individuals with known ...
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19 views

Ecological specialization and relative abundance

I am reading Evolution in Changing Environments by R. Levin but have a hard time. Claim At page 25, Levin says as a conclusion The more efficient a caste at meeting the contingency for which it ...
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1answer
91 views

What are Codominant vs Dominant Genetic Markers?

When talking about types of genetic markers, the adjective "dominant" and "codominant" are often used. I don't fully understand their definitions and found contradicting definitions. Foll and ...
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18 views

Statistical genetics: Allele frequencies that follow a Dirichlet distribution

From Foll and Gagiotti (2008) (software BayeScan). They consider a model where several subpopulation are derived from a unique ancestral population. We consider a set of $I$ loci and let $K_i$ be ...
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56 views

autosomal recessive population numbers

This question is background research for a science fiction / fantasy novel, my knowledge of genetic is very basic. It seems obvious to me that for genetic disorders that are autosomal recessive, if ...
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28 views

What model of epistasis best fit the reality?

In theoretical population genetics, it is very common to have to assume a model of epistatic interaction. The two most common models are the additive model and the multiplicative model. Additive ...
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27 views

Ewens-Watterson Test of Neutrality

The Ewens-Watterson test is one of the first test of neutrality (of no selection). Later came tests such as Tajima's D or Fu, Li's G and many other. Question Can you please make a description of how ...
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36 views

How would cloning affect conservation of rare species?

Many species are at risk of extinction, and cloning could be seen as a relatively quick method to produce large numbers of members of the species to aid in conservation efforts, especially if the ...
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1answer
36 views

Relationship between genetic diversity within and between species

Here is a quote from Wagner (2008) A second line of evidence [against neutralism] comes from the relationship between the mean number of polymorphic differences between alleles within a species, $\...
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84 views

How does the introduction of clones would affect population genetics? [closed]

Since the ability to clone animals gives another way to preserve species, this could help for the breeding process. It has been noted that with the ability to clone animals, endangered species can ...
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14 views

Effective population size of a continuously spread population

Is there any model to calculate (theoretical predictions) the effective population size of a continuously spread population? Imagine for example a population spread over an infinite 2D landscape. ...
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13 views

Effective population size of a metapopulation structured on a grid

Scenario Consider a rectangular metapopulation consisting of $x \cdot y$ demes, where $x$ is the number of deme horizontally and $y$ is the number of demes vertically. The population size per deme is ...
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1answer
45 views

How big advantage had a trait have to bring to evolve in the human evolution? [closed]

Yes, I've heard that we have evolved from the common ancestor with primates as intesively, as the chimpanzees. Sometimes I read about some enormously complex traits, evolutionary psychologists think ...
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1answer
46 views

Identity By Descent vs Identity By State

Background The concepts of Identity By Descent (IBD) vs Identity By State (IBS) are central in population genetics, yet I fail to fully wrap my head around the definitions. You can find examples ...
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37 views

Hardy-Weinberg equilibrium generalized to add inbreeding (non-random mating)

Background Quoting from Gillespie's book The level of inbreeding is measured by the inbreeding coefficient, $F_I$, which is the probability that two alleles in an individual are identity by ...
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54 views

Population size and genetic drift - What are the evidences?

Wright-Fisher model From the Wright-Fisher model of genetic drift, the random sampling of allele from one generation to the next is taken from a binomial distribution with parameters $2N$ and $p$, ...
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42 views

Is there a difference between macroevolution and group selection?

I encountered two different attitudes towards macroevolution: The first one included long-term microevolution such as the evolution of Cetacea. The second one included only macroevolution in terms ...
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49 views

What's the difference between evolution fitness and reproductive success?

What's the difference biological fitness and reproductive success in the biological terminology?
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1answer
54 views

Why is the probability of fixation of an allele equal to its frequency?

Introduction In a panmictic population, the probability of fixation of an allele at a neutral locus is equal to its frequency at that time. I will refer to this probability of fixation as calculated ...
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Runs of homozygosity - degree of inbreeding and disease associations

Been reading recently about methods to determine how inbred a particular person is by measuring their "runs of homozygosity." Loosly, these are defined as regions of the genome (typically >1Mb) where ...
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79 views

Why is there no symmetry in pigmentation when comparing people north and south of the equator?

If you are at the equator and start moving north, the further you travel, the lighter the skin of the indigenous peoples. Considering that we live on a ball, why do we not find the same traveling ...
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1answer
50 views

Can we say it's hybridisation if it's the same species?

If we mixed two population of the same species into the same environment and then they reproduce together, can we say it's hybridisation? The wikipedia definition is the following: Hybridisation (...
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51 views

Is $F_{ST}$ a probability and a correlation coefficient?

$F_{ST}$ is one of the most famous and most important statistics of all of evolutionary biology. Yet, many people misunderstand it or misuse the classical results from the literature on $F_{ST}$ (...
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110 views

Would a colony with only one male and female collapse?

This is a thought experiment: If we form a population with only a single founder pair, can this population survive? What would happen? Would this inbreeding cause the population to go extinct? Could ...
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53 views

How should one interpret heritability? Is it related to $R^2$?

From Wiki: Heritability estimates are often misinterpreted if it is not understood that they refer to the proportion of variation between individuals on a trait that is due to genetic factors. It ...
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1answer
28 views

“Heterozygotic expection” - when heterozygote differs from both homozygotes, but homozygotes are similar

For simple 2-alleles genetic model {a,A} and corresponding quantitative trait Q is typically true that Q(aa)>=Q(aA)>=Q(AA) or conversely Q(AA)>=Q(aA)>=Q(aA). For example, dominance means that Q(...
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43 views

Relation between heterozygosity and allelic diversity in founder effects/bottleneck?

Can someone try to explain me why allelic diversity falls faster than heterozygosity, reminding you that we're talking about bottleneck or a founder effect? Look at this graphic: It's clear to me ...
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1answer
73 views

What test to apply to detect genomic signatures of selection?

I would like to ask you for your sugestions for selecting a test to detect signatures of selection in the following mouse model: We have three groups: animals exhibiting trait A, trait B and controls....
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284 views

Why are the genomes of Humans 99.5% the same?

Human's DNA sequence is said to be roughly 99.5% equal. As far as I understand, this means that if I walked up to you and compared our DNA, the sequence of base pairs would be 99.5% the same. My ...
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2answers
209 views

Do mutant alleles result from mutation of the wild type?

The allele that encodes for the most common form of a phenotype in natural population is called a wild type allele and all the rest of the alleles encoding forms other than the wild type are called ...
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123 views

Effect of sex-ratio on the effective population size

As stated on this wikipedia article, the effective population size $N_e$ when the sex ratio differs from $\frac{1}{2}$ is $$N_e = \frac{4N_mN_f}{N_m+N_f}$$ I understand the biased sex-ratio ...
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54 views

Diffusion approximation to genetic drift

I am reading from the classical textbook Principles of Population Genetics, Hartl and Clark (pdf here). Introduction Let $f(p,x,t)$ denote the distribution of allele frequency $x$ at time $t$ ...
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75 views

Why don't the genetic similarities between ‘unrelated’ individuals of the same and different species outweigh the differences?

Ever since starting to learn about the concept of inclusive fitness during my BSc, I've been bugged by this questions: if inclusive fitness can account for many ‘altruistic’ behaviors, why don't the ...
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1answer
77 views

From STRUCTURE to FSTAT format

From numerical simulations I output a file that is input to STRUCTURE (Hubisz et al. 2009). I now realize that I would need to process my data with FSTAT (Goudet 1995). Both are text files. Is there ...
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1answer
260 views

Calculating pairwise Fst from allele frequencies

I am trying to refresh my memory on population genetics for a project, and I'm having some trouble. Assume I have genetic data on 3 populations with 5 individuals in each of a given species, with the ...
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Interpretation of F in inbreeding on the population level

The inbreeding coefficient for an individual gives the probability that the individual has two alleles at a locus that are IBD. What interpretation does the inbreeding coefficient have on the ...
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290 views

What is the difference between fixation and loss of alleles in a population?

When running a simulation in PopG, with parameters: Population size: 100 AA fitness: 1.0 Aa fitness: 1.0 aa fitness: 1.0 Mutation A to a: 1.0E-6 Mutation a to A: 1.0E-6 Migration rate between ...
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78 views

How do you create a .snp datafile?

I'm looking to use the software DIYABC 2.1.0 to apply approximate bayesian computing (ABC) to some resequenced data that I have. The resequenced data is in FASTA format however, and the software ...