P.C. Shannon

It’s my understanding that in his latest book, Stephen Wolfram asserts that humen beings are born with an understanding of physics. (I haven’t personally read the book.) I don’t think this is exactly the case. Rather, human beings are born with the capacity to understand physics, in much the same way we are born with the capacity to learn language. No one is brought into the world speaking English or Swahili, but we learn it over time. Some extreme cases of child abuse have demonstarted that if we don’t learn a language by the time puberty hits, then that capability is lost. Likewise, we all learn physics to some degree because we’re all exposed to it. A child born and raised in a zero-gravity environment would have a very different understanding of physics than her earthbound cousins.

Nonetheless, even if the knowledge itself isn’t encoded in our DNA, it is still humbling to realize that that molecule contains the power to enable us to learn. DNA is responsible for the structures that form in the brain, that then absorb experience and transform it into knowledge. This is where the size of the human genome comes into play. It seems farfectched to me to imagine that there’s a gene (or more specifically, an allele) for “physics brain structures” any more than there’s one for a dog’s olfactory lobes. It seems much more plausible that there are highly complicated mechanisms that control the development of these structures, especially in the embryo.

This idea of complex and intricate control mechanisms is borne out by the size of the human genome. It was once estimated to be 100,000 genes, but it is now thought to be closer to 30,000. Same number of base pairs, no matter what the count. All that extra data may not be just “wasted space.” Instead, perhaps it is highly complex and evolved control mechanisms, many of which function primarily (or exclusively) during embryonic development. And it is these control mechanisms that are really what separate human beings from nematodes.

Tyrosine kinases and signaling pathways are one example of a control mechanism that’s found only in higher animals. I imagine there are many many more.