A History of the Human Brain: A book review by Bob Morris


A History of the Human Brain: From the Sea Sponge to CRISPR, How Our Brain Evolved
Bret Stetka
Timber Press (2021)

Here’s a comprehensive — and entertaining — examination of human brain evolution.

In layman’s terms, the mind is what the brain does. At least that is what I was told when I was ten years old and had the opportunity to ask a scientist questions about the brain and the mind. Yes, I realize there is MUCH more to be said about both but — please correct me if I’m wrong — I think it would be impossible to write a book that provides an authoritative history of the human mind.

According to Bret Stetka, “The story of the human brain is meandering. It starts small, with simple, single-cell microbes and a host of weird sea creatures evolving early cell-to-cell communication, a harbinger of the neurons that would later coalesce into our nervous system…Through some combination of happenstance and ancestral adaptations, [Homo sapiens] endured when other humans did not. We were the strongest species on the African plains. Nor the fastest. It was our large, complex brain that kept us alive and, for better or worse, allowed us to influence the fate of the planet like no other species ever before.”

In his review of this book, Lloyd I Sederer observes, “Our guide and narrator, [Stetka], understandably, is particularly fascinated by what he calls, ‘Upright Citizens,’ particularly chimpanzees, bonobos, apes, and humans (all members of the Family of Hominids). I had no idea how I, too, would become enraptured by this odd lot of fellow creatures (and even more enraptured by human evolution) until I read Stetka’s tales. It has been said that a great book cannot be great due to its subject alone; the writer, as well, must be passionate about their subject and infect the reader with that same ardor. Stetka is a keen observer and raconteur. This book, his first, is replete with bon mots, phrases, wise asides, and a sprinkling of irony and humor, which make you want to turn to the individual beside you (in my case, my wife) and say, I gotta read you this! That is what awaits you in 229 pages (plus notes, bibliography, and index)—lest you think this book is a door stopper of 1000 pages!'” Actually, 271.

In or near the central business district in most major cities, there is a farmer’s market at which some merchants (at least pre-COVID) offer slices of fresh fruit as samples of their wares. In that same spirit, I now offer additional brief excerpts that suggest the thrust and flavor of Stetka’s lively style:

o “As actor and comedian Steve Carell told Wired in 2008, ‘Children are very smart, in their own way. A child’s brain is like a sponge, and you know how smart sponges are.’ The irony is that the story of the modern brain actually does begin with the sponge.” (Page 25)

o “Keep in mind that even with increasingly telling fossils and modern gene sequencing technology, tracing biologies trajectories can be an exhaustive exercise. As might be expected of a process largely based on random mutation, Darwinian evolution is a tortured mess. The tree of life is really more of a shrub, all tangled branches, dead-end twigs, extinctions, new adaptations, and new species.” (34)

o “A human population living in a sheltered, unchanging island existence wouldn’t have had the same adaptive pressures to evolve a big brain. They knew their ecosystem, predators, and food sources well. They didn’t have other humans to contend with. There wasn’t much environmental change for selection to act on. But the majority of humans on the mainland had to eke it out in dangerous ecosystems. A bigger, smarter brain was key to surviving and outsmarting our enemies and predators.” (84)

o “We share the vast majority of our DNA with both chimps and bonobos, and our best and worst tendencies seem tangled up in our shared gnomes. It’s impossible to say we got this quality or that directly from a shared ancestor with other species, but we’re offered a glimpse into aspects of our personalities by observing theirs.” (133)

o “Compared to other apes, Sapiens have very small teeth and a reduced jaw. It’s thought that this change occurred in part to accommodate for language, with a smaller instrument being better capable of controlling sound…If our preadaptations for communication and social complexity primed our brain to take over the world, it was one soft, fleshy food in particular that provided the fuel: meat.” (166)

o “It’s undeniable that when humans show up, we ruin everything.

“As members of Homo sapiens made their way out of Africa and around the world, we wreaked havoc on other species, especially the megafauna…We had little awareness of what we were doing. We lived the best we knew how based on our biology, instinct, and cultural creations. If there was available meat, we ate it. We conquered the world through a lethal combination of wits and a relentless use of resources.” (227)

o “Hopefully, our big brain thinks up new ways to exist on our planet responsibly, while at the same time addressing the damage we’ve done. Neuroscience will advance. Genomes will evolve. Culture will change by the second. And we may endure, just as our ancestors did 150,000 years ago., huddled in a rocky coastal cave, struggling to crack open an especially difficult oyster before the tide sets in.”229)

Obviously, no brief commentary such as mine could possibly do full justice to the scope and depth of Bret Stetka’s coverage and the value of the information and insights he provides. However, I hope I have at least indicated why I think so highly of his contributions to knowledge leadership.

A History of the Human Brain is a brilliant achievement. As Bret Stetka clearly indicated, it is ” the story of our big awkwardly complex brain and how it got here.”


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