Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

d below, A and B have offspring blings. Then, C and D have off. cousins. Assume

ID: 212150 • Letter: D

Question

d below, A and B have offspring blings. Then, C and D have off. cousins. Assume that all indi- digree are unrelated unless otherwise the pedigree illustrssed bel d D, who are full and F, who are spring ndi cated on the pedigree. a. Compute the coefficient of relatedness between E and D. b. Compute the coefficient of relatedness between A and G. c. Compute the coefficient of relatedness between B and H. Suppose C can help D at a cost of 0.05. How great ust the benefit to D be in order for natural selection d. to favor this helping behavior?

Explanation / Answer

Draw the tree as in the example below. Then mark the shortest possible path between two family members and count the number of steps between them. Each step across generations (parent to child) or between siblings counts as one. Once you have this number of steps (n), r = ½n, or ½ multiplied by itself n times.

a. The shortest relatedness is two stepped in case of E and D
D-C and C-E
r= 1/2*1/2 = 1/4

b. A and G are unrelated because the family tree is different. G is from an another tree that married F

c- B to H
1/2*1/2*1/2= 1/8