We all marvel at the diversity of life around us.
I am sure you have seen the unique behaviors of animals. How some animals hunt. Some animals migrate. Still others eat only meat, while others eat only plants.
Most of us understand that the behaviors of animals developed over long periods of time. In other words, they evolved to how they are today.
And yet very few of think about our own human evolutionary path. We rarely consider how the human ‘animal’ has adapted over time. What are human bodies adapted for?
In his book, “The Story of the Human Body”, Daniel Lieberman takes us on a journey to try and answer some of these questions. How and why did we evolve certain aspects of our bodies?. Why do we walk upright? Why are we better at endurance tasks? Why do we eat both meat and plants?
And, more important, why are we doing things TODAY that we are not evolved for – and paying the price in poor health.
Evolution moves slowly. We are essentially the same as our ancestors 50,000 years ago. Back then, we had to catch/find what we needed to eat. We had to roam to find new sources or to protect ourselves from seasonal changes. We were generally never completely ‘full’ and were reasonably active.
We evolved, like many other species, to adapt to a particular way of life over thousands of millennia.
But, in just 40 centuries through our ingenuity and cultural changes, we have drastically changed the environment that the human species lives in today.
We no longer match the environment for which we were evolved.
This has had a broad effect on what and how we eat, how often we are physically active, even how we sleep. This evolutionary mismatch‘ has led us to be generally less healthy. We are overweight/obese. We have weaker bones. We have less flexibility in our joints and muscles. We have less effective rest, more stress and regularly suffer from chronic, non-infectious diseases. And we often succumb to preventable ‘lifestyle’ diseases.
As the author points out, somewhere along the way we decided that things that make us comfortable are good for us. But, in most cases, these “creature comforts” are detrimental to our health and well-being.
This book is very deep and covers not only our evolutionary path but also how cultural change and current economics has positioned us in a perilous situation. A sampling of some of the enlightening information:
- We have evolved to be better endurance walkers/runners than any other species.
- Humans ability to sweat makes us uniquely adapted to be active during the heat of the day (most animals rest/sleep).
- We, of all the animals, have evolved to have a ‘child’ stage of development – we develop slowly.
- We evolved to store fat. But we also evolved to use it effectively if it is added in the correct manner and for the right reasons.
- Many of the chronic diseases and malaises that trouble us today come from a low-effort, energy rich diet coupled with a sedentary lifestyle.
“It is generally assumed and widely advertised that anything that makes you feel more at ease [comfortable], must be good.” However, sitting at work, driving to a store two blocks away, eating a frozen pizza rather than grilled vegetables, having soft-arch supporting running shoes – are all abnormal activities/behaviors from an evolutionary perspective.
Many of the potential health issues can be mitigated by these activities.
Changing our behavior for longer-term benefits is not easy. It takes consistent willpower and developing new habits that go against our instinctual, ‘natural’ (gene driven) judgments:
- Do I have the chocolate cake (which our genes crave) or the stalk of celery (which is better for us long-term)?
- Do I take the elevator (our genes want us to conserve energy) or the stairs ( our body will store the chocolate cake as fat if we don’t)?
As he points out: “We consistently discount the value of rewards in the present…relative to rewards in the [more] distant future…in proportion to the length of the delay.”
I can say that after reading this book, I immediately started to make changes in my life. I am now walking more, sitting less, staying away from processed foods (as much as possible – it is hard!) and eating more vegetables, fruits, and lean meat.
We are not well adapted to life in the ‘comfort’ of the modern world. And I, for one, will start integrating my evolutionary adaptions into the ‘strange environment’ we humans now exist in.