Behold! The Naked Ape
Survival of the Fittest: A Primer on Evolutionary Medicine
Jun 16, 2025
Evolutionary medicine is a legitimate but rather obscure branch of medicine. It studies humans and their ailments from the perspective of where we came from originally.
Homo sapiens evolved on the savannas of Africa about 300,000 years ago. Just to put the timeline in perspective, Christ lived 2,000 years ago so our species came into existence 150 times that ago. And moreover our species was preceded by several less developed Homo species over a period of several million years.
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The first humans probably did not wear any clothes and lived in the open unless they could find a convenient cave for shelter. We were hunter gatherers. The food we ate was mostly eaten raw (in spite of the fact that earlier Homo species had begun to master fire almost a million years earlier). That’s important because cooking removes a substantial portion of a food’s vitamins.
The only sweets we had were naturally sweet fruits, and honey (in limited supply and vigourously guarded by the bees).
We lived a very active, strenuous life – running, jumping, climbing, digging. All that activity burned a lot of calories – probably 4,000 or more per day. And because much of our food was raw and fresh, it was loaded with vitamins and other essential nutrients. With our diet of largely processed cooked food today, are we getting enough? (That’s a whole article in itself which I will save for another time.)
We did our business on the ground where our feces and urine became part of the earth where it provided fertilizer for plants.
We lived on the ground where we, like all other animals. were in constant contact with the millions of bacteria and moulds that live in soil. And we prospered. Indeed that dirt was (and still is) an important part of how our immune systems work.
(My university major was microbiology and I spent 20 years of my working life in medical labs. However I’ve developed these positions largely in the years since through observation and enquiry.)
Babies were born in the open on the ground where they too were exposed to all those organisms. Probably a few parasites too which also helps to develop some types of immunity
(The womb is sterile but the world is most certainly not. A baby’s first contact with bacteria is in its mother’s birth canal and those bacteria are incorporated into its intestinal flora which is essential for proper digestion.)
Breastfeeding of infants was universal.
We lived in isolated family groups so epidemics – if they occurred – were limited.
We likely never bathed unless we happened to have a lake nearby. We had no soap and cleanliness was not an issue. We didn’t brush out teeth or wash our hair. Then about 200 years ago (about .001% of our existence) we developed microscopes and could see bacteria and we realized that some of them could cause disease and that’s when our obsession with cleanliness began.
And then enterprising entrepreneus seized the opportunity and started promoting soaps and toothpastes and shampoos and disinfectants and snake oil … all the things that we had done without for hundreds of thousands of years.
But quite recently (less than 100 years) we’ve come to realize that many of those bacteria (and viruses) are part of us.
As animals have evolved, bacteria have been evolving in lockstep right beside us. Our bodies contain more bacterial cells than human ones and they (our microbiome) are essential for our health. But yes, some bacteria cause disease and diseases can kill but your best defence against those diseases is a strong immune system which ironically includes a healthy microbiome.
So what does all this have to do with anything.
The DNA we have today is the same DNA we had back on the savannas of Africa. That DNA gave us a big brain with the ability to invent things like clothes so we could live anywhere in the world. We invented huts so we didn’t have to live in the open, then houses and then high rises in large cities. We invented cars and trains and planes so we didn’t have to walk or run everywhere. We invented grocery stores so we didn’t have to hunt or or gather our food.
Modern life is largely sedentary. Maintaining the level of fitness that evolution designed us for requires regular visits to the health club … or not.
We have come a very long way but our DNA is still the same, designed for a hunter gatherer living in the open on the savannas of Africa. Our big brains have literally gone to our heads – we think we’re smarter than the evolutionary forces than gave us that brain and the potential that came with it.
Our DNA is far from perfect. We have some bad genes and they can kill us. Every miscarriage and still birth (approx 1 in 5 in Canada) is nature’s way of culling those bad genes. But humans in our wisdom take extraordinary steps to keep those babies alive – and if, by chance, they survive to maturity and have children of their own they will pass those bad genes on to their children. If a child has any close relative with diabetes they are 15x more likely to develop the disease themselves. Juvenile diabetes (type 1) was rare before the discovery of insulin – not any more.
Rather than taking extreme measures to keep babies with bad genes alive, the resources would be better spent on analyzing their (and their parents’) DNA so that in the future we could have the knowledge to do in utero diagnoses and counselling.
Our DNA developed in the absence of any drugs, except perhaps what we found in the plants around us. There were no antibiotics to disrupt our microbiome. And no analgesics to short circuit the body’s pain thresholds which are there to tell us to stop what we’re doing because we’re damaging ourselves and need time to heal.
Modern medicine has made incredible discoveries – I’m 80 years old and reasonably healthy because of it. But the medical community, and perhaps more importantly, drug and health companies are pushing ‘cures’ which ignore the millions of years of trial and error that got us where we are today. The fact that we’re here (and other species aren’t) is a pretty good indication that evolution got most of it right.
Our genes – both good and bad – get passed on through our children. To keep evolution on the right path we need to pay better attention to the long path that got us here.
