INCLUSIVE FITNESS AND THE EVOLUTION OF HELPING BEHAVIOR Jobn D. Krenz Minnesota
ID: 219895 • Letter: I
Question
INCLUSIVE FITNESS AND THE EVOLUTION OF HELPING BEHAVIOR Jobn D. Krenz Minnesota State University OBJECTIVES 1. 2. 3. Understand both components of inclusive fitness (direct and indirect) Understand the coefficient of relatedness or likelshood Use Hamilton's Rule, a cost-benefit equation to evaluate he correlation coefficients, to solve word-problems. lping-behavior decisioes that employs genetic Bill Hamilton (1964) said that our concept of fitness should be expanded to inchude non-descendent kin that survive because of our help (indirect fitness) and he coined the term "inclusive fitness" to encompass both traditional direct (descendent) fitness and indirect fitness A key concept introduced by Hamilton was that of the coefficient of relatedness (r) the degree to which relatives are likely to share alleles identical by descent. The coefficient is calculated as T -the coefficient of relatedness of individuals a and b-E (0.50 where, x - is the number of steps in a pedigree along a path from a to b that passes through a common ancestor E indicates to sum the calculations for each common ancestor of a and b. Hamilton's Rule is the cost-benefit analysis that helps us understand whether an animal should perform helping behavior B C where B is the number of nondescendent kin produced because of your help. C is the number of offspring not produced because of the decision to help a relative reproduce instead. rb is the coefficient of relatedness (mean proportion of genes shared by descent from common ancestor) between helper and nondescendant kin helped. re is the coefficient of relatedness (mean proportion of genes shared by descent from common ancestor) between helper and his own descendants that did not exist or survive because he chose to help non-descendants instead. Problem 1. At the family reunion, Grandmother Marie said to her grandson Pete that his daughter has got the same shape eyes that she had when she was young and of course she must've gotten from her. Pete, having been in Evolution 301, replied to her that there was a % chance that Marie's eye allele-if there was such a thing-got passed to his daughter. Draw a pedigree that would apply to this situation and use it to illustrate your calculation.Explanation / Answer
1). Inclusive fitness is an organism's ability to pass the gens to the offspring (subsequent generation) by considering the shared genes passed on by the siblings or other relatives of the organism, which can be direct (reproductive) or indirect (involves the colony members or relatives).
Altruism is the sense of helping others intentionally, means, at the cost of known risk. If the ratio of cost of the donor to the benefit of the recipient is less than "r", the frequency of altruistic trait increases in the population. Means, the increased frequency of altruistic trait benefits the population (increases the fitness of one group of the population). This is called as "Hamilton's rule," where "r" is the coefficient of genetic relatedness between donor and recipient.