Answer:
The next generation average time to flowering will be 98 days.
Explanation:
Before answering the question, we need to know a few concepts.
- Artificial selection is the selecting practice of a specific group of organisms in a population -that carry the traits of interest- to be the parents of the following generations.
- Parental individuals carrying phenotypic values of interest are selected from the whole population. These parents interbreed, and a new generation is produced.
- The selection differential, SD, is the difference between the mean value of the trait in the population (X₀) and the mean value of the parents, (Xs). So,
SD = Xs - X₀
- Heritability in the narrow-sense, h², is the genetic component measure to which additive genetic variance contributes. The heritability might be used to determine how the population will respond to the selection done, R.
h² = R/SD
- The response to selection (R) refers to the metric value gained or lost from the cross between the selected parents. R can be calculated by multiplying the heritability h², with the selection differential, SD.
R = h²SD
R also equals the difference between the new generation phenotypic value (X₁) and the original population phenotypic value (X₀),
R = X₀ - X₁
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Now that we know these concepts and how to calculate them, we can solve the proposed problem.
<u>Available data: </u>
- trying to decrease the maturation time in a population of sunflowers.
- the population mean time to flower is 100 days → X₀
- Chosen parental Plants mean flowering time is 90 days → Xs
- the narrow-sense heritability for flowering time is 0.2 → h²
According to what we sow previously, we need to find out the value of X₁, which reflects the next generation average time to flowering.
- We know that R = X₁ - X₀, so we need to clear this formula to calculate X₁
X₁ = R + X₀
We already know that X₀ = 100 days,
Now we need to calculate R.
We know that h² = 0.2,
Now we need to calculate SD
Xs = 90 days → Parentals media flowering time
X₀ = 100 → Population media flowering time
SD = Xs - X₀
SD = 90 - 100
SD = - 10 days
Knowing this, we can calculate R
o h² = 0.2
o SD = - 10
R = 0.2 x (-10)
R = - 2
- Finally, once we know the R-value we can calculate the X₁ value
X₁ = R + X₀
X₁ = - 2 + 100
X₁ = 98
