How did a species of primates come to dominate life on earth? The species is the fully erect hominid, Homo Sapiens.

The journey starts in Africa. Climate change turns forest into open savanna, and a line of primates adapts to the change. The last primate standing is Sapiens, an intelligent, aggressive, fire aware, weaponised, socialised endurance runner.

He hunts megafauna because the energy return on energy invested (EROEI) is high.

It's clear that the answer to domination lies in the brain of Homo Sapiens. His fire, tools, and weapons aren't enough.

Hominids aren't alone in having complex brains. They co-existed with other intelligent animals for millions of years. Many of their rivals were much larger, and more powerful. They found a place, but they didn't dominate.

The brain sizes of hominids started to increase rapidly about 2 million years ago.

This is related to the development of the prefrontal cortex, that part of the brain that merges "different inputs - such as vision and hearing, instinctual urges, emotions, and memories - into one integrated story". This increased connectivity "forms the basis of the human patterning instinct."¹ It's inherited, emerging early in life, and lasting a lifetime.

The ability to think in symbols is a cognitive breakthrough, allowing them to "break through the capacity constrains of working memory and construct the elaborate patterns of meaning that shape our lives."

Patterning is powerful but again, it doesn't seem to have lead to domination.

Not long ago (about 100,000 years), Homo Sapiens started to exert control. They embraced religion². They massacred herds of large animals³. Extinctions started, and followed them, as they journeyed out of Africa.

Nothing had changed outwardly in their physicality or in their technology (fire, tools, weapons). The change was an inheritance of unique psychological traits, and the impact of these traits caused other animals to walk in fear of them.

It was their ability to read the minds of complex life forms (theory of mind (TOM)) that enabled them to deceive⁴, and to be deceived (propagandised).

Importantly, TOM revealed to them the most unpleasant reality of all, their mortality. Once this unpleasant reality could be denied⁵, it was only a matter of time before any unpleasant reality could be denied.

Denial explains "a wide range of uniquely human features, such as risky behaviour, the optimism bias, depressive realism, suicide, religiosity, existential angst, bravery⁶, empathy, indirect reciprocity, and so on."

These deniers and deceivers are trying to create their own reality. They aren't acting to save themselves in the face of an increasingly unpleasant reality imposed by the laws of physics. They're talking about everything, except their energy predicament.

We are best described as a plague on earth, and plagues don't save themselves. They deplete their resources, and then they die.

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1. The Patterning Instinct: A Cultural History of Humanity's Search for Meaning - Jeremy Lent↩

2. Personal items are buried with the deceased indicating an understanding of mortality, and life after death.↩

3. They were reducing the EROEI of their prey leading them later into agriculture.↩

4. for example, lighting fires in order to stampede herds of mammoths over cliffs.↩

5. for example, humans are uniquely brave. Only they come out of the trenches for King and country knowing that death is almost certain.↩

6. Start with Rob Mielcarski's blog, Un-Denial and Ajit Varki's book, Denial, pdf, Did Human Reality Denial Breach the Evolutionary Psychological Barrier of Mortality Salience? and video, Awareness of Mortality: Mind over Reality Transition↩