Sep 04

“Big Brian” is not as easy to digest as Matt Ridley’s well-written, lucid “The Red Queen”, but promises an intriguing analysis in the “origins and future of human intelligence”. This book continues in the theme of my personal exploration in the areas of Genetics, Evolutionary Biology and Evolutionary Psychology.

Big Brain - Book Cover

Big Brain - Book Cover

Here’s a snippet from Chapter 3, which summarizes the reason for the remainder of the book:

We may think of brains as good things; big brains make smarter animals, so surely evolution wants to increase brain size. But brains are expensive.

So the argument goes: if these highly expensive parts are being expanded, the results must be valuable indeed.

As a result, it is often hypothesized that each brain size increase during primate evolution must have been strongly selected for, i.e., there must have been some strong behavioral improvement that made the brain increase advantageous in the fight for survival.

We posit quite a different hypothesis: that brains increase for biological reasons – which may be largely accidental – and that behaviors follow this increase … a big brain got randomly tossed onto the table and once there, it found utility.

modest and understandable gene variations stumbled onto these useful but relatively humble modifications.”

UPDATE: Finished the book. While the subject matter is good, the book could be better. I felt the organization of the book and the images were poor. But the “big picture” presented by the authors is interesting: that animal brains appear to have changed little, except for size and the associated plumbing. But the authors claim that this extra size allows the brain to elastically assume higher level functions. Key in their discussion is that there have been three large dislocations in brain size growth within our family: 2-4M years ago with Australopithecines, 500K-2M years ago with home habilis/erectus and then finally, most recently, to homo sapiens – amazingly, these changes in size fall linearly in place on a log graph of frontal area (mm3) vs. brain weight (mg x 1000).

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