Quote of the Day

What propels an embryo from one stage to the next-and makes one species different from another-is not a blueprint but rather an enormous autonomous library of the instructions contained within its genome. Each gene does double duty, specifying both a recipe for a protein and a set of regulatory conditions for when and where it should be built. Taken together suites of these IF-THEN genes give cells the power to act as parts of complicated improvisational orchestras. Like real musicians, what they play depends on both their own artistic impulses and what the other members of the orchestra are playing. As we will see in the next chapter, every bit of this process-from the Cellular Big 4 to the combination of regulatory cues-holds as much for development of the brain as it does for the body.

- Gary Marcus, The Birth of the Mind: How a Tiny Number of Genes Creates The Complexities of Human Thought