S. B. Hrdy
Origin of size difference

Chance size difference in single cell gametes
-> 2 types

......................Large ...	...Small
.........Competition ........for resources	...........Competition ...........for access ...
Even larger	...................Smaller & maneuverable

= ground rules for males & females*

"Hardier"......................................

"con-artist" "preying" "taking hostage"

Fusion -> sexual recombination -> Hedge against fluctuations

• * Size difference among males & females occurs in whole organisms, so why does the egg-sperm difference show anything about sexual differences?
• Moreover, sperm and egg are not male & female. (Indeed, in mammals, sperm determines sex.)
• Why not stay big in the competition?
• Why not fuse two big cells to get through hard times?
• Why fuse at all?
• Is this story only relevant to sexual organisms? What fraction of species are sexual?
• Is the hedge against fluctuations accepted as explanation of why sex? (Alternatives?)