Origins – Leakey & Lewin
Introduction
How did a monkey-like social creature become a cultured human living in structured societies? According to Leakey & Lewin, the answer lies in two key drivers of evolution: sharing and stimulation.
Sharing of work and food shaped cooperation and solidarity.
Adaptation led to behavioral changes, supporting survival and cultural development.
From Hunter-Gatherers to Farmers
The hunter-gatherer lifestyle
Hunter-gatherers lived in small groups integrated with the natural order. Fire provided safety, warmth, and longer evenings, which encouraged storytelling, myths, and rituals. Group hunting required coordination and reinforced solidarity, similar to wolves or lions.
Above all, sharing food—the spoils of hunting and gathering—was a major force in strengthening community bonds.
The shift to agriculture
Around 12,000 years ago, farming communities emerged. Agriculture:
Supported higher population densities, leading to villages and cities.
Encouraged specialization of activities and division of labor.
Fostered trade, exchanging grain for meat, tools, or other goods.
However, farming also brought challenges:
Sedentary life encouraged accumulation of material goods, creating greed and aggression.
Intimacy became harder in large communities.
Power structures emerged, controlling masses on a scale unknown to hunter-gatherers.
The Role of the Hands and Fire
The liberation of the hands was the only major somatic change enabling this transformation:
Toolmaking and technology.
Carrying food and water, aiding migration and safety.
Handling objects, bags, and weapons.
Meanwhile, fire:
Deterred predators.
Extended daylight with light and warmth.
Brought humans together socially, encouraging stories, rituals, and cooperation.
Hands capable of manipulation and a subtle language became the defining faculties of a cultured animal.
The Evolution of the Brain
Size and specialization
The brain evolved not just in size but in specialization. Though it represents only 2% of body weight, it consumes:
15% of blood circulation.
20% of total oxygen.
Roots in arboreal life
Living in trees fostered stereoscopic vision and prehensile hands, enabling primates to perceive a three-dimensional world. This amplified the senses, supported memory, and improved the categorization of information.
Perseverance and tenacity
Unlike most primates, humans developed focus and perseverance—qualities essential for successful hunting and long-term survival.
Key Takeaways
Sharing is the foundation of human society—work, food, and later trade.
Agriculture transformed communities, enabling growth but also sparking materialism, aggression, and social hierarchies.
Hands and fire unlocked technology, migration, safety, and culture.
The brain, specialized and energy-intensive, gave humans adaptability and learning capacity.
Conclusion
Human evolution rests on extreme flexibility and adaptability. From arboreal primates to structured societies, sharing and cooperation were central to survival.
But the story is not over. The final question remains:
👉 How will the technological revolution reshape the human brain and our ability to share—when even today, two-thirds of the world’s population struggles to eat properly?
