The evolutionary success of cooperation, seemingly antithetical to the 'selfish gene' paradigm, has long puzzled biologists. While individual natural selection favors traits that benefit the individual's own survival and reproduction, many species exhibit altruistic behaviors where individuals incur costs to benefit others. Kin selection, reciprocal altruism, and group selection are prominent theories attempting to reconcile this paradox. Kin selection posits that altruism towards relatives promotes the survival of shared genes. Reciprocal altruism suggests cooperation can evolve if individuals reciprocate benefits. Group selection argues that groups with more cooperators may outcompete groups with fewer. These mechanisms demonstrate that even 'selfish' genes can promote cooperation under specific ecological and social conditions.
Which of the following best summarizes the given text?
Correct: A
The paragraph introduces the paradox of cooperation versus the selfish gene, then explains how various theories (kin, reciprocal, group selection) resolve this paradox. Option B is too strong; it implies the 'selfish gene' paradigm is *insufficient*, whereas the text shows how cooperation can be explained *within* that framework. Option C incorrectly prioritizes kin selection over the others; the text presents them as equally prominent theories. Option D describes group selection only, ignoring the other explanations. Option A accurately identifies the central paradox and the three main evolutionary explanations offered.