In: Biology
Write Hamilton’s rule and discuss how it is used to explain the evolution altruism.
Ans:
Hamilton rule: William Hamilton proposed a quantitative measures for predicting when natural selection would favoured altrustic act. He pointed out that an altruistic gene will be favoured by natural selection when a certain condition is satisfied, known as Hamilton rule. The rule states that
rb > c
Where,
c = the cost incurred by altruist
b = the benifit gained by recipient
r = the genetic relatedness between donor and recipient
This cost and benifits are meaured in terms of reproductive fitness. r is the measure for the probability that any given is allele shared by any two individuals. The siblings share half of each parents contribution their genome, adding to a r = 0.5 and cousins share an r= 0.125. So, the higher value of r means the greater the probability that the recipient of the altruistic behavior will also posses the gene for altruism. It predicts that oranisms are more likely to behave altruistically towards their relatives than towards unrealted members of their species.