A new paper by evolutionary anthropologists Colin Shaw (University of Zurich) and Daniel Longman (Loughborough University) argues that modern life has outpaced human evolution. The study suggests that chronic stress and many modern health issues are the result of an evolutionary mismatch between our primarily nature-adapted biology and the industrialized environments we now inhabit.
A species out of sync with its environment
Over hundreds of thousands of years, humans adapted to the demands of hunter-gatherer life – high mobility, intermittent stress and close interaction with natural surroundings. Industrialization, by contrast, has transformed the human environment in only a few centuries, by introducing noise, air and light pollution, microplastics, pesticides, constant sensory stimulation, artificial light, processed foods and sedentary lifestyles.
“In our ancestral environments, we were well adapted to deal with acute stress to evade or confront predators,” explains Colin Shaw, who leads the Human Evolutionary EcoPhysiology (HEEP) research group together with Daniel Longman. “The lion would come around occasionally, and you had to be ready to defend yourself – or run. The key is that the lion goes away again.”
Today’s stressors – traffic, work demands, social media and noise, to name just a few – trigger the same biological systems, but without resolution or recovery. “Our body reacts as though all these stressors were lions,” says Longman. “Whether it’s a difficult discussion with your boss or traffic noise, your stress response system is still the same as if you were facing lion after lion. As a result, you have a very powerful response from your nervous system, but no recovery.”
Health and reproduction under pressure
In their review, Shaw and Longman synthesize evidence suggesting that industrialization and urbanization are undermining human evolutionary fitness. From an evolutionary standpoint, the success of a species depends on survival and reproduction. According to the authors, both have been adversely affected since the Industrial Revolution.
They point to declining global fertility rates and rising levels of chronic inflammatory conditions such as autoimmune diseases as signs that industrial environments are taking a biological toll. “There’s a paradox where, on the one hand, we’ve created tremendous wealth, comfort and healthcare for a lot of people on the planet,” Shaw says, “but on the other hand, some of these industrial achievements are having detrimental effects on our immune, cognitive, physical and reproductive functions.”
One well-documented example is the global decline in sperm count and motility observed since the 1950s, which Shaw links to environmental factors. “This is believed to be tied to pesticides and herbicides in food, but also to microplastics,” he notes.
Designing environments for wellbeing
Given the pace of technological and environmental change, biological evolution cannot keep up. “Biological adaptation is very slow. Longer-term genetic adaptations are multigenerational – tens to hundreds of thousands of years,” Shaw says.
That means the mismatch between our evolved physiology and modern conditions is unlikely to resolve itself naturally. Instead, the researchers argue, societies need to mitigate these effects by rethinking their relationship with nature and designing healthier, more sustainable environments.
According to Shaw, addressing the mismatch requires both cultural and environmental solutions. “One approach is to fundamentally rethink our relationship with nature – treating it as a key health factor and protecting or regenerating spaces that resemble those from our hunter-gatherer past,” he says. Another is to design healthier, more resilient cities that take human physiology into account.
“Our research can identify which stimuli most affect blood pressure, heart rate or immune function, for example, and pass that knowledge on to decision-makers,” Shaw explains. “We need to get our cities right – and at the same time regenerate, value and spend more time in natural spaces.”