You observe an example of an apparently altruistic act by an animal that seems to reduce its near-term likelihood of reproductive success. What would be the least plausible explanation for its behavior?
A) The act aids the reproductive success of individuals sharing a high proportion of genes with the altruistic individual.
B) The act is only apparently altruistic; over the long term, the behavior actually contributes to individual fitness.
C) The act increases the inclusive fitness of the animal performing it.
D) The act is advantageous because it helps the species to survive and reproduce, even if the altruist itself does not.
E) From the information provided, it is impossible to determine the least plausible explanation.

Question

Quizplus · Accepted Answer

This explanation is the least plausible because it suggests that the act is beneficial only for the species as a whole, but not for the individual performing the act. Altruistic behavior generally involves a cost to the individual, so there must be a direct or indirect benefit to the individual in order for the behavior to evolve and persist. In contrast, the other explanations propose specific mechanisms by which the behavior could benefit the individual performing the act.

You Observe an Example of an Apparently Altruistic Act by an Animal