Meathead Hypothesis: Brain Size vs.

¶ … Meathead" Hypothesis: Brain Size vs. Complexity

It is shocking how simple the human brain is. As Sapolsky points out, the relative difference between the human and chimp brains is one of the number of neurons (Sapolsky 3-4). While Sapolsky is probably partially right, the truth is more complicated however. This is interesting when posited against research that Cro Magnon Man actually had a bigger average brain size that modern man (Zyga). While this fact might elicit a laugh when horrible standardized test scores are considered the author quotes Ms Zyga for the express purpose of suggesting that there are probably other factors opposed to the number of neurons here. In addition, she points out that some areas of the human brain are more compressible and that mastication and simple robusticity may have been factors (ibid). After all, Sapolsky does not even mention the number of pathways or their complication of connectivity to explain a chimpanzees lack of higher culture, nuance and soul. Indeed as one of the comment respondents on the Physorg.com article site remarks "Kinda like processors becoming smaller and more efficient, if smaller means more intelligence I guess killer whales are more intelligent than humans (ibid)."

However, after castigating Sapolsky with the "meathead" evidence, let's look at his advantages. First of all, he is only examining one factor for us in the article. From a chemical and molecular standpoint, he is actually on to something. It is shocking from a chemical and molecular standpoint at how relatively uncomplicated we are. Good disciples of Darwin that we are, it is almost a commandant or something that we have a right to chemical complexity. Certainly, genetic sequencing issues are the meat and potatoes of classical evolutionary theory and are exactly what we would expect.

It is also fascinating that from a genetic standpoint that we are only 2% different from the chimpanzees. From a spiritual standpoint (yes, Creationists do not have monopoly on such reflections), it is humbling and should give us all reason for pause and humble meditation. In our Darwinian smugness at being at the top of the food chain, we should not forget that there are not many rungs in the ladder. Maybe there is a reason for these great apes to fling things at us in the zoo through the bars of the cage. There but for the grace of Darwin go I.

As the A's, C's, G's and T's switch on an off, it's fascinating to think about the minor and major changes, environmental and otherwise that could have made things different. The stray transcription factor would make the difference. Is there such a thing as counterfactual evolution (like counterfactual history)? It is fun to think about this.

Most of the 2% differential applies to factors we would absolutely expect, such as olfaction and reproduction. Sapolsky points out a fascinating fact that what makes the human and chimpanzee brains different. A neuron in a sea slug and a neuron in a human are essentially the same. Both chemically and physiologically are the same. As he points out, the number of genes here is an issue (Sapolsky 2).