You have embarked upon an endeavor to breed trophy Elk with large antlers and ar

Question

You have embarked upon an endeavor to breed trophy Elk with large antlers and are maintaining a herd of 200 elk. The sex ratio in the census population (Nc) is 50:50 but elk are highly polygamous and it turns out that four (4) of the bulls are breeding with all the females. You are concerned that the skewed breeding sex ratio may be lowering the genetic effective size of your herd.

A.What is the effective population size (Ne) of this herd?   

B).Assume the antler size is controlled by a single dominant allele (H). The frequency of the H allele in your elk herd is 0.8.

(1).Calculate the 95 percent confidence limits of the allelic frequency for allele H. Use Ne calculated in A above.  

2).What will be the expected heterozygosity in your elk herd in 3 generations? (2 points)

C).You have monitored your elk population over the past four years and the actual population sizes over the past four years were: 56, 25, 72, and 40. What is the effective population size (harmonic mean) of this species over that time?

Explanation / Answer

Ne = (4*Nm*Nf)/(Nm+Nf); Nm=Nf = number of males and females.

But here this is not the case. N=200; Out of these 200, 100 are males and 100 are females. But due to highly polygamous nature, only four bulls are breeding with 100 females. So, Nm = 4; and Nf = 100

Applying these values in formula = Ne = (4*4*100)/ (4+100) = (1600/104) = 15.38

Frequency of ‘H’ allele = 0.95%0.8 = 0.76

Fitness of heterozygote = 0.32/0.64 = ½

Expected heterozygosity after one generation = (present heterozygosity * fitness) = 0.32*½ = 0.16

Expected value of p^2 after first generation = 0.64/0.64 * 0.64 = 0.64

Expected value of q^2 after one generation = 0.04/0.64* 0.04 = 0.04/16 = 0.0025

Expected heterozygosity after 2nd generation = 0.16* (0.16/0.64) = 0.04

Expected heterozygosity after 3rd generation = 0.04 * (0.04/ 0.64) = 0.0025

= 1/ (1/56) + (1/25) + (1/72) + (1/40)

= 1/ (0.018 + 0.04 + 0.014+ 0.025)

= 1/ 0.097

= 10.31

**Note: Please post such questions one by one. Do not post such lengthy questions.

Related Questions

Navigate

• Browse (All)
• Browse Y
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.