Human Brain: "Enormous Biochemical Complexity"

A new biochemical atlas finds consistency, complexity, and precision in the human brain.

The Allen Institute for Brain Science has just published its Human Brain Atlas in Nature (Hawlyrycz et al., “An anatomically comprehensive atlas of the adult human brain transcriptome, Nature 489, 20 Sept. 2012, pp. 391–399, doi:10.1038/nature11405). Science Daily printed this summary of what they did:

The results of this study are based on extensive analysis of the Allen Human Brain Atlas, specifically the detailed all-genes, all-structures survey of genes at work throughout the human brain. This dataset profiles 400 to 500 distinct brain areas per hemisphere using microarray technology and comprises more than 100 million gene expression measurements covering three individual human brains to date. Among other findings, these data show that 84% of all genes are expressed somewhere in the human brain and in patterns that are substantially similar from one brain to the next.

Even so, they “only scratched the surface” of the contents of their data set. The findings should lay to rest two common misconceptions in popular mythology, (1) that humans only use 10% of their brains, and (2) that right-brained people are different than left-brained. Science Daily said,

The right and left hemispheres show no significant differences in molecular architecture. This suggests that functions such as language, which are generally handled by one side of the brain, likely result from more subtle differences between hemispheres or structural variation in size or circuitry, but not from a deeper molecular basis.

In addition, they found high homogeneity in the gray matter, suggesting that “same basic functional elements are used throughout the cortex”.

The statement that brain patterns are substantially similar between brains may inform philosophical questions about how well we can communicate with one another. The three examined were “high-quality, clinically unremarkable brains,” they said – i.e., not geniuses, but ordinary folks. (The sample size is still too small to make generalizations about differences due to sex and ethnicity.)

Overall, the complexity of the brain was the story. Science Daily put it this way: “human brains share a consistent genetic blueprint and possess enormous biochemical complexity.” One collaborator said, “The tremendous variety of synapses we see in the human brain is quite striking.” The paper began, “The enormous complexity of the human brain is a function of its precise circuitry, its structural and cellular diversity, and, ultimately, the regulation of its underlying transcriptome.” The “transcriptome” refers to the set of genes that are transcribed into proteins. As stated, the team found 84% of all genes are expressed in the brain.

There was only one reference to evolution in the paper, and that in the last sentence. The team was discussing differences between brains of animals and humans. “The primary feature that distinguishes the human brain from that of other species is the enormous expansion of the neocortex relative to total brain volume.”  They commented on the fact that transcription appears relatively uniform across brain regions. All they could say about evolution was a suggestion: “the relative homogeneity of the two largest neuronal structures… is striking and suggests an evolutionary expansion of a canonical cortical blueprint.”

Evolution was useless in the paper, as usual. Their final comment has the hallmarks of a required pinch of incense to Caesar Darwin.  The team was looking for transcription (a design function) and structure (a design function) and found a lot of it.  They found precision.  They found complexity.  They found consistency. What’s Darwin got to do with it?

It’s worth remembering that examination of the structure of the brain has little bearing on the soul.  You can look all you want at gene, neuronal, and protein activity and never see “consciousness” or personality.  It would be like looking at the inner workings of Big Ben and looking for time.  You will not see time.  You will see machinery and processes, but time is a concept beyond the materials and methods used to measure it.

The data set will also not support common ancestry.  Take any strict Christian or Jew and they will agree that we have much in common with the animals, including eyes, legs, and brains.  They believe we are creations made for the same habitat as the other animals.  We breathe the same air and eat similar food.  It is not surprising we share the same basic machinery with similar structure and composition.  Chimpanzees have a cerebellum; so do we.  Since the soul is not located in neurons or proteins, this says nothing about the existence of the soul.  The paper did point out that only humans have a much larger neocortex.  That’s reasonable, because we reason.

Similarity can show common design or common ancestry. Precision machinery of high complexity, by contrast, points to a factor beyond its components: intelligence.  To say the brain created itself by an aimless process is just as foolish as claiming a supercomputer network with multiple interacting components (both hardware and software) emerged out of random shuffling of metals and electrons.  Only intelligence can bring together multiple disparate parts and fashion them for complex function and communication.  What more evidence does anyone need for an intelligent cause commensurate with the product observed?  The very act of thinking about that shows we share that kind of intelligence.