Family Planning

The Selfish Gene: Chapter 7 summary

    This chapter focuses on reproduction, population numbers in specific groups of a species, and how evolution has played a role in controlling birth-rates. Individuals must balance between bringing new individuals into the world and caring for the ones already in it. Or, "child bearing vs. child caring," as Dawkins puts it. Using one is not evolutionarily stable as we saw in the previous chapter. By using the idea that individuals unconsciously choose to regulate their birth-rates "for the good of the species," Wynne-Edwards makes the claim for group-selection. In this chapter, Dawkins uses the selfish gene theory to explain these same phenomena.
    Unlike humans, all other organisms lack the ability to foresee the devastating effects of overpopulation. Populations are controlled by their ecological limitations, large groups of individuals deplete resources which ultimately lead to starvation. But why don't we see this with all population? The Wynne-Edwards explanation would be that species work altruistically to artificially control birth-rates. As seen with species that control territories and fight for the right to mate, this explanation says that only certain individuals gain the right to mate, thus controlling birth-rates. It even goes on to explain that individuals conduct censuses of their population numbers to determine their birth-rate.
    What the selfish gene theory tells us is that individuals are actually acting out of selfishness to preserve their genes even though this can look altruistic. There is a surprising number of "costs" that are associated with bearing children. Costs that will determine the proportion of children that will survive to carry on their parent's genes. It turns out that individuals do control their own birth rates, but not in the same sense as Wynne-Edwards understands it. There is an ideal number of children that would provide the lowest burden of care, protection, and weaning by the parents whilst having the greatest chance that genes would be preserved in the surviving children. Each species has a more or less specific brood size each breading season and this has been determined by the evolution of the species in its specific environment.
    One experiment was seen to support the Wynne-Edwards idea of autistic group selection. It used mice living in a confined space with endless supplies of food and water in order to see how birth-rates were affected when the population filled the space. As the population grew, the birth-rate slowed down before filling the space, why was this? Wynne-Edwards would explain this as the mice controlling their numbers for the good of the group. The selfish gene theory concludes nearly the same, but that the mice  would have no idea that the resources were endless and that "animals tend to have the optimum number of children from their own point of view." This would mean having less children in order to optimize their chance that the maximum amount of children would go on to preserve the parents genes.