Eye-Opening Insights from a Fascinating Book

The Story of the Human Body: Evolution, Health, and Disease

One of the most convincing threads of health research, for me, is to eat and move more, like we did for the millions of years our bodies were becoming human. This golden age of human evolution, from a few million years ago up to now, was when we learned to move on two legs and evolved the profound mental capacity that separates us from our ape cousins, our unique heritage from nature and the gods of evolution.

Our forebears spent about 99.99% of that time as hunter-gatherers on the plains of Africa. Our bodies were built for that world, not the modern one we find ourselves in. This “evolutionary mismatch” is a condition that Daniel Lieberman explores in depth in his profound and fascinating book, The Story of the Human Body: Evolution, Health, and Disease.

Let’s start with the fact that for all this time, our ancestors moved about 10 to 15 miles a day, mainly walking but running when they had to, in order to find enough food to stay alive, either by foraging or hunting. This activity consisted of movements like throwing, pulling, pushing, bending, reaching, twisting, climbing, carrying, and fighting. It also consisted of teamwork and cooperation, which involved communication skills and eventually language. And all those various activities involved our senses and increasing memory to aid in sensing potential sources of food as well as danger.

It was a highly precarious existence, with danger lurking almost everywhere and wariness and caution being the watchwords of life. Yet our ancestors survived, and we eventually dominated the landscape and developed tools to adapt to all types of climates, which enabled various early-human species to start moving around the globe. (This only started about 100,000 years ago for modern humans, which surprised me, especially given that we only started speaking in what could be considered early languages about 50,000 years ago.)

Now let’s take those rugged prehistoric bodies, used to living in raw nature and fending for themselves, and plop them into modern life. This is US! And while our settled, civilized lifestyle happened over a few thousand years, that is just a blink of an eye in evolutionary time. And our very modern life of comfort, abundant food, lack of movement, and antiseptic cleanliness over the past 100 years is an even smaller percentage of that time.

“Evolutionary Mismatches”

In his book, Lieberman presents several “evolutionary mismatches” that have ensued, including:

Movement – Our bodies thrived on movement, were used to it, and needed it not only to secure food but to survive, whether that was fighting, hunting, or running away from danger. They also danced and played, lived on the ground, connected to the earth, and were part of the landscape.

Food – For all that time our bodies were used to the flesh and fat of animals and fish, including bugs and worms, plus plants, roots, and fruit of every description, including nuts and seeds. The occasional bit of honey was hard-won and a rare, sweet treat. There were no foods other than these. Any grains were eaten as seeds. The first flour wasn’t even made until about 10,000 years ago.

Metabolism – This is perhaps Lieberman’s biggest takeaway. Because of the scarcity of food, our stone-age bodies were built to store, as fat, any excess energy sources we ingested in times of plenty. This was quickly burned off when the next period of scarcity happened. This precious storage mechanism, which is still how our bodies operate, is completely at odds with a world filled with easy access to food, and especially low-quality, high-calorie, and low-fiber processed carbohydrates full of bad-for-you types of fat.

Life rhythm – We lived according to the light and darkness of the day. Having spent considerable time in Kenya and Tanzania, I know that day and night in that equatorial climate is roughly equal, about 12 hours each. Darkness lasts from 6:00 or 7:00 at night to 6:00 or 7:00 in the morning. Night was not only for sleeping and resting. It was also for watching out for night predators. Days were mostly dedicated to finding or hunting for food, as well as preparing and eating it. We ate when food was available, which wasn’t always the case, as well as when we were hungry, which was most of the time. Hunger and fasting were part of life.

Chewing – Early peoples didn’t have cavities. Lieberman credits this to the almost complete lack of anything sweet in their diet and also to the amount of chewing that was necessary to break down wild plants and raw or partially cooked meat. Their teeth and jaws got a bigger workout than ours do today, because we eat so much processed and overcooked food. He advocates chewing nonsweet mastic gum to keep our jaws strong.

Modern comforts – Lieberman explores everything from modern footwear to eyeglasses as sources of not using our bodies the way they were used, which in turn exacerbates weakness of those body parts instead of strengthening. He is a big fan of barefoot and/or minimalist footwear to repair our feet and use them more closely to the way they evolved to support various types of movement.

Microbiome – While he doesn’t spend much time on this subject, I will add it as one of my own observations. Our ancestors spent all their time in direct contact with nature, which exposed them to bacteria and viruses that caused their bodies to either fight or build up immunity to any dangerous “bugs.” This is the reason scientists have studied modern hunter-gatherer tribes; they have much more diverse gut microbiomes than those of us who live in developed, industrialized countries. This diversity has increasingly been linked to greater health and longevity.

This book is well worth anyone’s time who is serious about their health, the backstory to how and why our modern lifestyle contributes to health problems, and what we can do to counteract the negative effects of our modern lifestyle to secure later-life health.