I keep thinking about the difference between pre-human and fully human — between Neanderthal, say, and us — and it’s occurred to me that the most significant distinction may be in terms of conscious control.
This idea grows out of a notion I’ve been toying with for years — that much of evolution has been a process of incremental internalization.
Hundreds of millions of years ago, for example, the hot new trend among primitive life-forms involved the development of bodily organs to take over functions that had previously been left up to the environment. Instead of passively allowing the sea to wash through them, they developed a digestive system that could pull in nutrients and eject the waste and a circulatory system to carry oxygen and nutrients to every cell. As time passed, they added shells or skeletons for stability, limbs for propulsion, and various appendages for grasping.
For higher-order creatures, biological evolution was eventually supplemented by behavioral evolution — but the goal was still to replace chance with control. Instead of depositing their eggs in the sand like a turtle and leaving the hatchlings to fend for themselves, they might feed and protect their babies like a dinosaur or mammal. Or they might create a specialized mini-environment to provide greater safety and comfort: a nest, a burrow, or an ant hill.
Among our own human lineage, however, there has been a further step — where taking control becomes a matter not of more advanced instincts but of conscious thought.