The evolution of the human brain, and how its increase in both size and complexity accelerated after our line split off from the chimpanzees', is discussed in today's Science Times by Nicholas Wade. Scientists are trying to determine which genes, and how many, define the difference between us and our lowbrowed close cousins.
What's comical about the article is that, while they blast as superstition the notion of an "intelligent designer," scientists can't resist anthropomorphizing "evolution" as just that:
The finding of changes in a large number of genes is an example of evolution's propensity for tinkering - for reconfiguring old components in order to build something new, said Dr. Gary Marcus, author of "The Birth of the Mind," a recent book on genes and the brain. This supports the idea of evolutionary psychologists that the mind is designed to accomplish specific tasks, in Dr. Marcus's view. [Emphasis mine]
Almost makes you envision "evolution" as a little Gepetto at his workbench in a leather apron, doesn't it? Maybe this is just a limitation of language, especially when trying to explain science to laypeople. Yet it has the effect of involuntarily smuggling back in the sense of a designer with a telos, a purpose. The name of this purpose is simply "evolutionary pressure" -- the survival advantage that accrues to favorable random mutations. But from the sound of it, deep down, the scientists have trouble believing it's entirely random themselves.