[Campbell Biology P.1209] WHAT IF? Suppose you applied Hamilton's logic to a situation in whi... | Practice Question

WHAT IF? Suppose you applied Hamilton's logic to a situation in which one individual is past reproductive age. Could there still be selection for an altruistic act?

  • A: Yes, if it benefits close relatives who are still reproducing.
  • B: No, because the individual cannot directly reproduce.
  • C: Only if the act directly increases its own lifespan.
  • D: Only if it involves reciprocal altruism with non-relatives.

Explanation

Hamilton's rule and the concept of inclusive fitness state that an altruistic act can be favored by natural selection if the benefit to relatives, weighted by their degree of relatedness, outweighs the cost to the altruist. Even if an individual is past reproductive age, its relatives may still be reproducing and carrying many of the same genes. Therefore, helping these relatives survive and reproduce can indirectly pass on the altruist's genes, leading to selection for the altruistic trait.