From Herbert Gintis:

Re: Spider sex cannibalism: it may come down to size (Sept. 15): Your headline, Demystifying spider sex cannibalism: There’s no deep, com­plex rea­son why fem­ales eat the males—they’re just hung­ry, two re­search­ers say” is quite misleading. There is not a single “theory” of the phenomenon that doesn’t accept that females eat males because they are hungry. The debate is about why male “allow themselves” to be eaten. This fine study strengthens the traditional story, but does not simplify it.

The question is: why do males evolve so that they can be eaten, rather than so that they can escape and have further inseminations? There is only one answer I know of: copulations in the species are so rare that the male supplies more to its offspring by being eaten than it does by having a chance at more offspring.

Herbert Gintis
Santa Fe Institute and
Central European University
Northampton, MA 01060