Seed size/number tradeoff summarized

"Seed size represents a fundamental trade-off, within the strategy of a species, between producing more small seeds versus fewer larger seeds from a given quantity of resource allocated to reproduction. The trade-off and its consequences were formalized in the model by Smith and Fretwell (1974). There is always selection pressure to produce more seeds, since more seeds represent more offspring (although there may be a lower limit to the seed size that permits a functional seedling to be produced (Raven, 1999)). On the other hand, larger, better-provisioned offspring have a greater chance of successful establishment, described by the Smith-Fretwell function....The best outcome from the mother's point of view is to maximize the ratio of seedling establishment chance to provisions invested in each seed..."