River Out of Eden - God's Utility Function

God's Utility Function

This chapter explores the meaning of life or, in other words, the purpose of life. This is the why question about life which philosophers and theologians have been pondering in vain for ages, and is a counterpart to the how question about nature which engineers have been able to resolve successfully.

Dawkins opens the chapter quoting how Charles Darwin lost his faith in religion, "I cannot persuade myself that a beneficent and omnipotent God would have designedly created the Ichneumonidae with the express intention of their feeding within the living bodies of Caterpillars." We ask why a caterpillar should suffer such cruel punishment. We ask why digger wasps couldn't first kill caterpillars to save them from a prolonged and agonizing torture. We ask why a child should die an untimely death. And we ask why we should all grow old and die.

Dawkins rephrases the word purpose in terms of what economists call a utility function, meaning "that which is maximized". Engineers often investigate the intended purpose (or utility function) of a piece of equipment using reverse engineering. Dawkins uses this technique to reverse-engineer the purpose in the mind of the Divine Engineer of Nature, or the Utility Function of God.

According to Dawkins, it is a mistake to assume that an ecosystem or a species as a whole exists for a purpose. In fact, it is wrong to suppose that individual organisms lead a meaningful life either. In nature, only genes have a utility function – to perpetuate their own existence with indifference to great sufferings inflicted upon the organisms they build, exploit and discard. As hinted at in chapter one, genes are the supreme lords of the natural world. In other words, the unit of selection is the gene, not an individual, or any other higher-order group as championed by proponents of group selection.

As long as an organism survives its childhood and manages to reproduce thus passing its genes down to the next generation, what happens to the parent organism afterwards does not really bother genes. Because an organism is always at the danger of dying from accidents (a waste of investment), it pays for the genes to build an organism which pools almost all its resources to produce offspring as early as possible. Thus we accumulate damages to our body as we age and harbor late-onset diseases such as Huntington's disease which have minimum impact on the evolutionary success of our gene overlords.

Genes are pitilessly indifferent to who or what gets hurt, so long as DNA is passed on. Dawkins wrote at the end:

During the minute it takes me to compose this sentence, thousands of animals are being eaten alive; others are running for their lives, whimpering with fear; others are being slowly devoured from within by rasping parasites; thousands of all kinds are dying from starvation, thirst and disease. It must be so. If there is ever a time of plenty, this very fact will automatically lead to an increase in population until the natural state of starvation and misery is restored.