The evolution of anisogamy or gamete size dimorphism is a fundamental transition in evolutionary history. and it is the origin of the female and male sexes. Although mathematical models attempting to explain this transition have been published as early as 1932. the 1972 model of Parker. https://www.diegojavierfares.com/mega-offer-Classic-Premier-Navy-Drapery-Fabric-by-Premier-Prints-30-Yard-Bolt-super-offer/