What is the selection coefficient in Hardy-Weinberg?
The selection coefficient (s) of a given genotype as related to the fitness or adaptive value (W) of that genotype is defined as s = 1 – W. (Fitness is the relative probability that a genotype will reproduce.)
How do you calculate selection coefficient?
Selection coefficient is a measure of the relative strength of selection acting against a genotype. Calculate the selection coefficient (s) by subtracting each fitness value from 1.0 (that is, s = 1-w). Interpretation of selection coefficient: sdd = 0.0 means genotype dd is not being selected against.
What is a coefficient of selection in evolution?
The coefficient of selection is usually taken to be a measure of the extent to which natural selection is acting to reduce the relative contribution of a given genotype to the next generation. Denoted as s, the selection coefficient is a number between zero and one.
What would the selection coefficient need to be for 95% of the mice to have the dominant phenotype in just 50 years record your answer below?
So, you will need to look at column D of the worksheet called “main worksheet.”Scroll down until the value is greater than 0.95. Record your answer below. It would take about 936 generations for 95% of the mice to express the dominant dark-colored phenotype.
How can the Hardy-Weinberg equation be used to model selection?
1 Answer. The Hardy-Weinberg principle is used when describing a population of organisms in which the organisms do not change. This principle explains the requirements of a population in order to remain constant (no mutations or evolution) for generations. So basically, there would be no natural selection.
What is the selection coefficient for the BB genotype?
Genotype Bb has a selection coefficient of 0.3, and genotype bb has a selection coefficient of 0.4.
How can the Hardy Weinberg equation be used to model selection?
Which of the following is an example of directional selection?
Examples. An example of directional selection is fossil records that show that the size of the black bears in Europe decreased during interglacial periods of the ice ages, but increased during each glacial period. Another example is the beak size in a population of finches.
What does P Q 1 mean?
In order to express Hardy Weinberg principle mathematically , suppose “p” represents the frequency of the dominant allele in gene pool and “q” represents the frequency of recessive allele. p+q=1 since the sum of both frequencies is 100% .
What is 2pq in Hardy-Weinberg?
In the equation, p2 represents the frequency of the homozygous genotype AA, q2 represents the frequency of the homozygous genotype aa, and 2pq represents the frequency of the heterozygous genotype Aa.
What is dominance coefficient?
The coefficient “h” is the dominance coefficient. If h=0 then allele A is dominant. If h=1 then allele a is dominant. And if h=0.5 then the fitness of the heterozygote is exactly intermediate between the two homozygotes. If h is negative the heterozygote will actually have higher fitness than either homozygote.
What does natural selection act on genotype or phenotype?
Natural selection acts on the phenotype (the traits or characteristics) of an individual. On the other hand, natural selection does not act on the underlying genotype (the genetic makeup) of an individual. For many traits, the homozygous genotype, AA, for example, has the same phenotype as the heterozygous Aa genotype.
What is an example of stabilizing selection?
Stabilizing Selection When selective pressures select against the two extremes of a trait, the population experiences stabilizing selection. For example, plant height might be acted on by stabilizing selection. A plant that is too short may not be able to compete with other plants for sunlight.
How do you calculate allele frequency after selection?
The initial frequency of allele A is (49 + 49 +42)/200 = 0.70. After selection, only 49 AA and 42 Aa individuals survive, for a total of 91 individuals surviving. The frequency of allele A, p, is now (49 + 49 + 42)/(91 + 91) = 140/182 = 0.769.
What do p2 2pq and q2 represent?
p2 + 2pq + q2 = 1 mathematically represents Hardy-Weinberg’s principle used to calculate the genetic variation of a population at equilibrium. It states that the allele frequencies in a population are stable and remain constant from one generation to another.