The Green Beard Mechanism is Bogus
This essay is a lightly reworked version of material from Debunking the Selfish Gene . Reproductive altruism can’t evolve, because it is less adaptive than reproductive selfishness. Suppose that a population contains organisms of both types. Some are reproductively altruistic toward other members of the population. The rest are reproductively selfish. The selfish organisms receive a benefit from the altruistic organisms, while the reverse is not true. So, on average, the selfish organisms will be more reproductively successful. The selfish trait will always be positively selected, while the altruistic trait will always be negatively selected. Eventually, the selfish trait will completely replace the altruistic trait. The selfish trait is selectively stable at 100% in the population. That is why group selection theory is wrong. Group selection does not exist, because the organism is the reproducing unit, and thus organisms are individually selfish reproducers. There are so...