Homo sapiens have existed for roughly 200,000 years, and for about 95 percent of that time, our lifestyles underwent relatively little change. We lived in small nomadic groups, hunted and foraged, and made a comparatively small impact on our environment. Our bodies and minds evolved for these conditions.
But radical changes in our ability to control our surroundings have thrust us into the urban landscapes of the last several hundred years, leaving no time for our biological blueprints to adapt. The result is a species trying to apply the same old rules to a new game. In other words, behaviors that once aided our survival thousands of years ago may not be suited to the way we live today. Evolutionary biologists call this phenomenon “evolutionary mismatch,” and the effect may have significant implications in addressing both public health and the climate crisis.
One effect of evolutionary mismatch is the advent of mismatch diseases, such as diabetes, cardiovascular disease, and particular kinds of cancer. These were much less common in our prehistoric ancestors. They’ve come about because certain behaviors that once seemed advantageous in a resource-scarce environment, such as eating all the high-calorie food you can get your hands on, translate poorly in a post-scarcity world. Western society has spent decades making unhealthy, calorie-rich products widely available, even subsidizing them. Such actions have not only tested the limits of our bodies but have also pushed nature well past its capacity.
Dietary issues are not the only example of evolutionary mismatch. Humans, like many animals, have an innate desire to maintain bodily homeostasis and overall comfort. It drove our ancestors to engage in sedentary, energy-conserving behaviors. Now that many of us have the opportunity to opt out of physically active lifestyles, such choices can drive us away from the exercise that we need to stay healthy. It may also lead to environmentally destructive behaviors, such as driving instead of walking.
Many of our instinctive, shortsighted desires may be misaligned with our longer term goals for health and well-being. If we truly examine our values in life, they often coincide with the health of the planet. We mustn’t separate ourselves from the environment that we evolved in, as that is the very same environment in which we are optimized to thrive.
The economist Adam Smith is famous for his “invisible hand” metaphor, in which he proposed that individual people acting in their own best interest economically will bring about what is best for society as a whole. We must accept, however, that we all have blind spots, such as preferring short-term gratification over long-term planning, giving preference to our in-groups over the perceived “other,” and making irrational decisions. These behaviors may have been inconsequential or even beneficial for our ancient ancestors, but now, with 7.8 billion people on the planet, we need a new ethical framework. We need a system that balances consideration for our long-run success with short-term goals, shifts us from dog-eat-dog individualism to more widespread collaboration, and supports integration instead of separation from our natural environments. A new social contract is imperative for a coherent, cooperative social state in which environmental capital is regenerated and sustained to support us all.