Genetics In Everything

Apropos (sort of) of the John Rawls/Mark Kleiman/Brad DeLong discussion of reciprocity and free trade below, a few days ago R. Ford Denison discussed the evolution of babysitting behaviors, and commented:

Major transitions in evolution have often involved loss of independence, as discussed last week. Most female bees work to increase their mother’s reproduction, rather than laying eggs themselves. Less extreme examples of helping others reproduce are known in some animals. “Kin selection” favors helping relatives, if the cost of helping is less than the benefit to the one helped, times their relatedness to the helper. This is known as Hamilton’s Rule. As Haldane put it, “I would jump into a river to save two brothers or eight cousins.” “Cost” and “benefit” are measured in number of offspring and “relatedness” is relative to one’s usual competitors.

That is all.