The Dark Side of Human Evolution

By: Greg Schmalzel

Have you ever wondered if life would be better had we not developed these massive, complex societies with our over-reliance on technology? What if we just remained hunter-gatherers living in small groups? Would there be less strife and despair?

The idea of the “noble savage” - a primitive, non-westernized person who lives a utopian life of peace, unaffected by the plagues of civilization - is misleading. We like to romanticize these early days of human evolution and society, but this is largely unwarranted. Life for any biological being in the natural world is a struggle.

“Life is suffering” - a quote attributed to Buddhism, and biologically, this is almost always the case. 

Suffering is a fundamental aspect of reality and an inevitable experience.

The story of the human species is no exception. While we justifiably celebrate the ingenuity of early humans, their art, their tools, and their migrations across the globe, there is another side to this tale – one far less romantic, yet no less important to understanding who we truly are. 

Imagine, if you will, a scorching savanna millions of years ago. A group of early humans moves cautiously through the open grasslands, their eyes scanning for predators. They are no longer safe in the trees, where their ancestors once lived. The shifting climate has driven them to adapt - to walk upright. But this new way of moving comes at a cost. Their exposed position leaves them vulnerable to lions and hyenas, and the relentless sun beats down on their unprotected skin. Bipedalism has opened up new opportunities for survival, but it has also exposed them to immense dangers. Those new dangers must then be accounted for with new adaptations.

Adaptations are a species’ response to suffering.

In this video, we’ll be looking at the struggles that our human ancestors experienced throughout prehistory and into the early stages of civilization. This includes conflict – humans turning on one another for resources; diseases ravaging their fragile communities, claiming the young and the old alike; and famine struck without warning, leaving entire groups to wither away in the face of merciless environments.

These are the darker chapters of human evolution. The battles fought, not just against nature, but against each other. The silent killers of famine and disease, shaping us in ways both brutal and profound. For within this darkness lies the story of how hardship forged the resilience, adaptability, and ingenuity that define us as a species.

To understand where we come from, we must not only celebrate our triumphs but confront the struggles that made them possible. This is the dark side of human evolution.

If you'd prefer the video format of this article, click here.

Violence, Conflict, and Warfare

Human nature has long been debated: are we inherently good or bad, and has society tamed or worsened us? Anthropology suggests we are capable of both peace and violence, with social structures fostering cooperation while never entirely eliminating conflict. From modern violent crime to wars, humanity's capacity for aggression is undeniable and deeply rooted in our evolutionary past.

Our closest primate relatives, chimpanzees and bonobos, offer insights into early human behavior. Both species are genetically equidistant from humans, yet their contrasting behaviors highlight different evolutionary strategies for managing aggression.

• Chimpanzees display both reactive aggression (impulsive outbursts) and proactive aggression (calculated, premeditated violence). They engage in lethal border patrols and dominance disputes.
• Bonobos, by contrast, are less prone to reactive aggression and resolve conflicts through grooming or sexual interactions, emphasizing peace over violence.
• Humans, positioned between these two strategies, suppress reactive aggression for social cooperation (like bonobos) while retaining proactive aggression for strategic purposes, such as warfare or competition (like chimps).

Evidence of violence extends throughout human evolution. For example, the Sima de los Huesos site in Spain, dating back 430,000 years, contains the earliest evidence of interpersonal violence. A Neanderthal skull exhibits deliberate blunt-force trauma, interpreted as an early homicide. Similarly, the Shanidar Cave in Iraq reveals both cooperation and conflict among Neanderthals. Shanidar 1 survived severe injuries due to group care, while Shanidar 3’s rib wound may indicate violence, potentially with Homo sapiens.

As Homo sapiens became the sole surviving hominins, large-scale violence emerged. At Jebel Sahaba in Sudan, a Late Stone Age cemetery shows over 60% of individuals with trauma consistent with recurring violent conflict. This violence was likely driven by competition for resources, exacerbated by environmental instability. Such patterns reveal how environmental pressures shaped early human aggression.

And with environmental uncertainty, comes food scarcity. A major driver of evolutionary change is a species' ability to acquire the nutritional requirements for survival. Because food is a non-negotiable for survival, small changes in the distribution of that food in the environment can result in big adaptations. So do we see evidence of food scarcity and famine in the evolutionary history of humanity? Let’s take a look.

Famine and Food Scarcity

The search for food has profoundly shaped human evolution, driving physical adaptations, survival strategies, and societal changes. While periods of scarcity such as droughts, loss of game, or harsh climates posed existential threats, they also served as crucibles for resilience and innovation. For early hominins like Australopithecines, their large jaws and robust teeth adapted to processing tough fallback foods, such as nuts and tubers, during lean times. Microwear analysis of their teeth shows a diverse diet, highlighting their ability to survive fluctuating resources, a trait that became central to later human evolution.

Famine’s legacy is etched into the archaeological record, especially through physiological markers like enamel hypoplasia and Harris lines, which indicate childhood stress from malnutrition or disease. For example, a study of pre-contact Native American remains revealed widespread evidence of these markers, suggesting significant periods of scarcity in later hunter-gatherer and early agricultural societies. However, research comparing more recent hunter-gatherers and agriculturalists challenges the notion of frequent starvation in pre-agricultural times. Hunter-gatherers’ mobility and diverse diets provided resilience against food shortages, unlike agriculturalists, whose dependence on staple crops made them vulnerable to crop failures and famine.

The transition to agriculture marked a turning point, introducing greater food insecurity despite its promise of surplus. Archaeological evidence shows increased stress markers like hypoplasia during the Holocene, underscoring the nutritional and social costs of settling into agrarian lifestyles. This shift serves as a sobering reminder that "advancements in human evolution" often come with unforeseen vulnerabilities.

Disease and Illness

Human ancestors faced significant threats from disease long before the advent of cities and civilizations. These illnesses arose from their survival activities - hunting, gathering, and migration through unpredictable landscapes - putting immense selective pressure on our species. The evolutionary struggle with pathogens dates back 7 million years, to the split from our common ancestors with chimps and bonobos. Migration into new ecologies exposed humans to novel diseases, favoring those with better immunity. Modern hunter-gatherer societies, which still lose up to 60% of individuals to disease before reproduction, offer insight into the health challenges faced by ancient humans.

The emergence of various infectious diseases in relation to key migrations and events in human history (Karlsson, E., et al. 2014. “Natural selection and infectious disease in human populations.” Nat Rev Genet 15, 379–393.)

Pathogens have been a constant presence, as evidenced by the discovery of ancient diseases like adenovirus and herpes in 32,000-year-old Siberian remains. However, small, mobile populations of hunter-gatherers could not sustain large-scale outbreaks. This changed with the Agricultural Revolution, about 12,000 years ago, when denser, sedentary populations enabled the rise of epidemics and zoonotic diseases, many stemming from close contact with domesticated animals.

Major historical epidemics have launch unprecedented tragedy, with death tolls soaring to into the millions. Here are just a few examples:

• The Plague of Athens - 75,000-100,000 people (about 25% of the population)
• The Justinian Plague - 15–100 million people (25–60% of the Late Roman Empire’s population)
• The Black Death - about 50 million people (up to 70% of some European cities)

These outbreaks reshaped societies through massive population loss and social disruption but also drove medical and public health innovations. Diseases often exploited human connection and close proximity, thriving on the very cultural and societal bonds that define humanity.

Colonial contact introduced catastrophic epidemics to indigenous populations, such as the dramatic decline in Mexico’s population due to European-introduced diseases. This tragic pattern likely repeated countless times throughout human history, as migrating groups encountered unfamiliar pathogens and exchanged immunity burdens. Disease has been a relentless force shaping human evolution, survival, and societal change.

Conclusion

Between violence, intermittent bouts of food scarcity, and lethal disease, humans have experienced their fair share of hardships. These were the darker moments of our evolution.

But, on the other hand, human evolution is responsible for the development of great innovation. Arguably the pinnacle of prehistoric, technological innovation comes from the Americas and is attributable to the Clovis culture. Check out my video on the Clovis culture here to explore the tools these people developed and their fascinating ways of life.

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