Several weeks back I wrote a piece for the Telegraph about how too few of us scientists stop to remind ourselves of the wonder of Darwin’s theory. “It should blow your mind,” I said. But it would be a shame if Darwin’s skeptics take comfort in scientists exhibiting awe for the complexity of nature. And it would also be a shame if Darwinists like me are deterred from communicating this awe with the worry that skeptics will somehow take comfort.
To see why no comfort should be taken, let’s step away from natural selection for a moment and consider the most complicated object in the known universe: your brain. Any neuroscientist will be happy to admit that we are still woefully ignorant about how the brain works. Our understanding of the brain’s mechanisms is moving forward quickly, and accelerating, but we have a very long way to go. And the idea that computationally meager neurons can, in large numbers and larger interconnectivity, underlie the mental life we cherish is, well, mind boggling.
But as boggled as neuroscientists might be about the brain’s mechanisms, consider what no neuroscientist is in the least confused about: that the brain is the mechanism underlying our mental life. The evidence that the brain, and not some other thing, is the mechanism underlying our thoughts is so overwhelming it is hardly worth discussing.
The difference here is one of “how” versus “that”. Discovering how the brain instantiates our minds is orders and orders of magnitude more difficult than discovering that the brain instantiates our minds. While this distinction is obvious for the brain, the point can often be overlooked for evolution. Comprehending exactly how the mechanism of natural selection underlies the diversity and complexity of life on Earth is an astronomically more difficult science problem than showing that natural selection is the mechanism. The “how” of natural selection is as difficult as the “how” for the brain, perhaps moreso. But the “that” of natural selection is another story, and is teeming with evidence.
Skeptics of evolution often aim at the “how”, and seem to believe that if scientists cannot fully answer the “how” question, then Darwin is all wet. But by that standard, neuroscientists should begin doubting that the brain underlies thoughts every time someone asks a difficult question about how the brain works.
Mark Changizi is the author of The Vision Revolution, and is a professor in the Department of Cognitive Science at Rensselaer Polytechnic Institute.