Scientists' alarm signal: Humans are no longer keeping pace with the world they have created in recent centuries

Humans have adapted to living in nature and have remained anchored in a world different from that created by industrialization, a study warns. He shows that the accelerating pace of modern change has outstripped the human body's ability to adapt and is having effects on health and well-being.

Humans were adapted to living in nature, study shows. Photo: Freepik.com

A recent study published by anthropologists Colin Shaw (of the University of Zürich) and Daniel Longman (of Loughborough University) shows that the modern world has developed faster than human biology can adapt.

Researchers argue that chronic stress and many of today's health problems originate in a fundamental mismatch between human biology, primarily adapted to the natural environment, and the challenges posed by contemporary industrialized environments.

From episodes of stress to continuous stress

For hundreds of thousands of years, humans evolved for a world of movement, nature and short episodes of stress, not the constant pressure of modern life, say the authors of the study titled “Homo sapiens, industrialization and the environmental mismatch hypothesis”.

“In our ancestral environments, humans were well adapted to cope with acute stress, to avoid or confront predators. The lion appeared from time to time and you had to be prepared to defend yourself or run away. The bottom line is that the lion was leaving.” says Colin Shaw, quoted by Science Daily.

Modern stressors such as traffic, workplace pressure, social media and persistent noise activate the same biological mechanisms that helped humans survive in the face of predators. But unlike situations in the past, these sources of stress rarely go away.

“Our body reacts as if all these stressors were lions. Whether it's a difficult discussion with the boss or the noise of traffic, the stress response system is the same as when you face lion after lion. The result is an extremely strong nervous system response with no recovery time.” claims Daniel Longman, quoted by the science publication.

Man, the factor of accelerated changes on the planet

The authors of the research show that for most of the history of the human species, nature has influenced and shaped human life. Although the changes made to the terrestrial biosphere by humans have been visible for over 10,000 years, their pace and extent accelerated dramatically with the onset of the Industrial Revolution at the end of the 18th century.

“Industrialization has profoundly transformed our natural habitats, driving rapid urban sprawl, increasing dependence on fossil fuel energy, and causing environmental contamination, ecosystem degradation, and biodiversity loss,” show the authors of the study.

Today, most of the world's population lives in heavily industrialized urban areas, and these differ fundamentally from their ancestral natural habitats. They create unprecedented environmental challenges and, at the same time, lack key natural elements associated with optimal body health and functioning.

“Although the adaptive capacity of humans has enabled survival in diverse and fluctuating environmental conditions, this capacity is limited. The rapid industrialization of our habitat is likely to overwhelm this adaptive capacity and impose selective pressures that threaten our evolutionary fitness.” research shows.

Falling fertility rates blamed on pollution

The authors of the review say that a growing body of observational and experimental evidence indicates that industrialization adversely affects biological functions essential for survival and reproduction and, by implication, for evolutionary success.

“Specifically, environmental contamination resulting directly from industrial activities, such as air, noise and light pollution or the accumulation of microplastics, is associated with impairment of reproductive, immune, cognitive and physical functions. Chronic activation of stress response systems, which further exacerbates these biological dysfunctions, also appears more pronounced in industrialized areas.” the authors state.

Industrial environments overstimulate stress systems and undermine both health and reproduction. Evidence such as the global decline in fertility and the rise in the incidence of chronic inflammatory diseases point to the biological cost of this mismatch, the researchers add.

An example presented in the study is the constant decrease in the number of spermatozoa and their motility, observed since the 1950s and attributed by the authors to environmental exposures. Air pollution, which is significantly higher in urban areas, is also associated with impaired reproductive function. According to the study, between 1973 and 2018, increased air pollution was associated with a 51.6 percent decrease in global sperm concentration and a 62.3 percent reduction in total sperm count. Another analysis cited by the scientists shows that air pollution is associated with a decrease in the concentration of spermatozoa, their total number and their mobility.

“There is a paradox: on the one hand, we have created wealth, comfort and impressive health systems for many people on the planet, but on the other hand, some of these industrial achievements have harmful effects on our immune, cognitive, physical and reproductive functions,” says anthropologist Colin Shaw.

Declining fertility rates in much of the world and rising incidences of inflammatory and autoimmune diseases are presented by anthropologists as evidence that modern environments are putting excessive pressure on human biology. The two authors argue that societies must act deliberately to reduce these pressures, strengthening the connection with nature and creating healthier and more sustainable environments.

“We need to do cities right and at the same time regenerate, value and spend more time in natural spaces”concludes Colin Shaw.