Allele Frequencies Equation -
p + q = 1
Genotype Frequencies Equation -
p2 + 2pq + q2 = 1
Number of genotypes for a given number of alleles Given n alleles at a locus, the number genotypes possible is the sum of the integers between 1 and n:
The general formula for finding the sum of a set of integers from 1 to n is:
Genotypes = n * n+1 / 2
(10 * 11) / 2 = 55
This breaks down to 10 homozygous genotypes and 45 heterozygous genotypes. The sum of the allele frequencies would still need to equal 1 :
p + q + r + s + t + u + v + w + x + y = 1
As would the sum of the genotype frequencies:
p2 + 2pq + 2pr + 2ps + 2pt + 2pu + 2pv + 2pw + 2px + 2py + q2 + 2qr + 2qs + 2qt +2qu + 2qv + 2qw + 2qx + 2qy + r2 + 2rs + 2rt + 2ru + 2rv + 2rw + 2rx + 2ry + s2 + 2st+ 2su + 2sv + 2sw + 2sx + 2sy + t2 + 2tu + 2tv + 2tw + 2tx + 2ty + u2 + 2uv + 2uw +2ux + 2uy + v2 + 2vw + 2vx + 2vy + w2 + 2wx + 2wy + x2 + 2xy + y2 = 1
The Hardy-Weinberg equation describes allele frequencies in populations. It predicts the future genetic structure of a population the way that Punnett Squares predict the results of an individual cross. The equation calculates allele frequencies in non-evolving populations. It is based on the observation that in the absence of evolution, allele frequencies in large randomly breeding populations remain stable from generation to generation.
In real populations, evolution does occur and allele frequencies vary over time. This divergence between real, evolving populations and theoretical, non-evolving populations allows the Hardy-Weinberg equation to be used to explore the effect of evolution on populations. Two major factors that cause real populations to diverge from the equilibrium predicted by the Hardy-Weinberg equilibrium are genetic drift and natural selection.
Genetic drift is the random variation that results in specific individuals producing more or less offspring than predicted by chance alone. This is most pronounced in small populations and is a major reason real allele frequencies do not remain at Hardy-Weinberg equilibrium values. Genetic drift is random and as such does not result in populations becoming more adapted to their environment.:
Natural selection increases the frequency of a favored allele over another and can cause significant departures from Hardy-Weinberg equilibrium.
Assuming a trait controlled by two alleles where p is the frequency of one allele and q is the frequency of the other allele, the sum of the frequencies must equal 1:
p + q = 1
Given p and q, the Hardy-Weinberg equation is:
p2 + 2pq + q2 = 1
Where:
The Hardy-Weinberg Equilibrium only holds if evolution is not occurring. For evolution to not occur, seven conditions need to be met:
While real populations don’t maintain the stable allele frequencies predicted by the Hardy-Weinberg equilibrium, the equation can be used to determine the rates and types of evolutionary change and the types of changes occurring in a population.
"Mind your Ps and Qs" means to be careful about your behavior, essentially "mind your manners" - it implies being polite and watching what you say or do in a particular situation; essentially, to be on your best behavior. [1, 2]
Key points about the phrase: [3, 4, 5]
Generative AI is experimental.
[1] https://www.jbcharleston.jb.mil/News/Commentaries/Display/Article/238481/mind-your-ps-and-qs/
[2] https://dictionary.cambridge.org/us/dictionary/english/mind-p-s-and-q-s
[3] https://www.theguardian.com/notesandqueries/query/0,5753,-3280,00.html
[4] https://www.generalsurgerynews.com/Opinion/Article/12-20/Mind-Your-Ps-and-Qs/61399
p + q = 1
Genotype Frequencies Equation -
p2 + 2pq + q2 = 1
Number of genotypes for a given number of alleles Given n alleles at a locus, the number genotypes possible is the sum of the integers between 1 and n:
- With 2 alleles, the number of genotypes is 1 + 2 = 3
- 3 alleles there are 1 + 2 + 3 = 6 genotypes
- 4 alleles there are 1 + 2 + 3 + 4 = 10 genotypes.
The general formula for finding the sum of a set of integers from 1 to n is:
Genotypes = n * n+1 / 2
(10 * 11) / 2 = 55
This breaks down to 10 homozygous genotypes and 45 heterozygous genotypes. The sum of the allele frequencies would still need to equal 1 :
p + q + r + s + t + u + v + w + x + y = 1
As would the sum of the genotype frequencies:
p2 + 2pq + 2pr + 2ps + 2pt + 2pu + 2pv + 2pw + 2px + 2py + q2 + 2qr + 2qs + 2qt +2qu + 2qv + 2qw + 2qx + 2qy + r2 + 2rs + 2rt + 2ru + 2rv + 2rw + 2rx + 2ry + s2 + 2st+ 2su + 2sv + 2sw + 2sx + 2sy + t2 + 2tu + 2tv + 2tw + 2tx + 2ty + u2 + 2uv + 2uw +2ux + 2uy + v2 + 2vw + 2vx + 2vy + w2 + 2wx + 2wy + x2 + 2xy + y2 = 1
Drift and Selection
The Hardy-Weinberg equation describes allele frequencies in populations. It predicts the future genetic structure of a population the way that Punnett Squares predict the results of an individual cross. The equation calculates allele frequencies in non-evolving populations. It is based on the observation that in the absence of evolution, allele frequencies in large randomly breeding populations remain stable from generation to generation.
In real populations, evolution does occur and allele frequencies vary over time. This divergence between real, evolving populations and theoretical, non-evolving populations allows the Hardy-Weinberg equation to be used to explore the effect of evolution on populations. Two major factors that cause real populations to diverge from the equilibrium predicted by the Hardy-Weinberg equilibrium are genetic drift and natural selection.
Genetic drift is the random variation that results in specific individuals producing more or less offspring than predicted by chance alone. This is most pronounced in small populations and is a major reason real allele frequencies do not remain at Hardy-Weinberg equilibrium values. Genetic drift is random and as such does not result in populations becoming more adapted to their environment.:
Natural selection increases the frequency of a favored allele over another and can cause significant departures from Hardy-Weinberg equilibrium.
Assuming a trait controlled by two alleles where p is the frequency of one allele and q is the frequency of the other allele, the sum of the frequencies must equal 1:
p + q = 1
Given p and q, the Hardy-Weinberg equation is:
p2 + 2pq + q2 = 1
Where:
- p2 equals the proportion of the population that is homozygous for allele 1
- q2 equals the proportion of the population that is homozygous for allele 2
- 2pq is the proportion heterozygotes in the population.
The Hardy-Weinberg Equilibrium only holds if evolution is not occurring. For evolution to not occur, seven conditions need to be met:
- No mutations: changes in allele frequencies are not changing due to mutations.
- No natural selection - All genotypes have the same reproductive success.
- The population is infinitely large
- Mating is completely random
- No migration - There is no flow of genes in or out of the population due to migration.
- All individuals produce the same number of offspring.
- Generations are non-overlapping
While real populations don’t maintain the stable allele frequencies predicted by the Hardy-Weinberg equilibrium, the equation can be used to determine the rates and types of evolutionary change and the types of changes occurring in a population.
"Mind your Ps and Qs" means to be careful about your behavior, essentially "mind your manners" - it implies being polite and watching what you say or do in a particular situation; essentially, to be on your best behavior. [1, 2]
Key points about the phrase: [3, 4, 5]
- Origin is unclear: While the exact origin is debated, one theory is that it might relate to the lowercase letters "p" and "q" which can easily be confused when typesetting, signifying the need for attention to detail. [3, 4, 5]
- Usage: You would say "mind your Ps and Qs" when reminding someone to be respectful and well-mannered, particularly in a formal setting. [1, 2]
Generative AI is experimental.
[1] https://www.jbcharleston.jb.mil/News/Commentaries/Display/Article/238481/mind-your-ps-and-qs/
[2] https://dictionary.cambridge.org/us/dictionary/english/mind-p-s-and-q-s
[3] https://www.theguardian.com/notesandqueries/query/0,5753,-3280,00.html
[4] https://www.generalsurgerynews.com/Opinion/Article/12-20/Mind-Your-Ps-and-Qs/61399
Exploring Ethylene-Related Genes in Cannabis sativa: Implications for Sexual Plasticity
Sexual plasticity describes an organism’s ability to change its phenotypic sex in response to environmental, chemical or physiological cues without a change in sex chromosome karyotype. Cannabis sativa L. (cannabis) is a medically important dioecious crop, with a pair of heteromorphic XY sex...
www.biorxiv.org
