Is human intelligence a gift from viruses?

In a world ruled by microbes, viruses, and bacteria, how ‘superior’ are humans really?

Are We the Parasites, or Are They?

Earth is approximately four and a half billion years old. Humans appeared only three to four hundred thousand years ago. And civilization? That is a story of merely ten thousand years. But microorganisms? Bacteria have existed on this planet for roughly three and a half billion years. Viruses perhaps even longer. Standing in this context, if we claim that Earth belongs to us and that microorganisms are the parasites here — that becomes one of the most laughable claims in history.

In truth, this Earth belongs to the microorganisms. We have settled on their planet, we breathe in the atmosphere they created, we burn the resources they left behind to drive our cars — and yet we believe ourselves to be the crown of creation.

Who Is the Real Supplier of Oxygen?

“Plant trees, save the environment” — we hear this slogan every day. But there is a great dishonesty embedded in that phrase. Of the oxygen in Earth’s atmosphere that we draw in with every breath, approximately 70 percent comes from the ocean — specifically from marine phytoplankton and other marine algae. These tiny single-celled organisms float on the ocean’s surface and carry out photosynthesis using sunlight, continuously, across ages.

We call the Amazon the lungs of the Earth. But in reality, all terrestrial forests combined — from the Amazon to the Congo Basin, from boreal forests to the Sundarbans — supply only approximately 28 to 30 percent of Earth’s oxygen. The Amazon alone contributes a portion of that. And the ten trees planted in your backyard? That contribution is so minuscule that expressing it numerically would require a parade of zeros after the decimal point.

Consider this — the oxygen without which you cannot survive is being produced largely by the very microorganisms we dismiss as “parasites.”

The Fuel on Which Civilization Stands

The backbone of modern civilization is fossil fuel. Without oil, gas, and coal, today’s economy, transportation, electricity, and industry are simply unimaginable. What is the primary source of these fuels?

Billions of years ago, the bodies of tiny marine microorganisms and algae living on the ocean floor accumulated layer upon layer. Buried beneath the sediment of the seabed, subjected to immense heat and pressure over geological timescales spanning hundreds of millions of years, that organic matter transformed into petroleum and natural gas. Later, as tectonic plates shifted and the ocean floor slid beneath landmasses, these reserves of oil and gas came to be found on land or near coastlines.

In other words, the oil fields of Saudi Arabia, the gas pipelines of Russia, the wealth of the Middle East — these are all empires built upon the bodies of dead microorganisms. The civilization we proudly call the ultimate expression of human intelligence is, in reality, living like a parasite on the bodily legacy of organisms that died billions of years ago.

Did Viruses Give Us Our Intelligence?

One of the most mysterious questions in human evolution is this — chimpanzees, gorillas, bonobos, and orangutans are all close relatives of humans, evolved from the same ancestors. So why did only humans develop such complex language, engage in abstract thought, and build civilization? Genetic differences alone cannot explain this vast gap in intelligence.

Scientists have turned their attention to a fascinating hypothesis — ancient retroviruses. Millions of years ago, certain viruses infected our ancestors and permanently embedded their genetic material into human DNA. These “endogenous retroviruses” (ERVs) now account for approximately eight percent of the human genome.

Research has shown that some of these viral genes play a role in forming synaptic connections in the brain. A gene known as Arc — which is essential for memory formation and learning — has a structure resembling that of viral capsid proteins. Additionally, the Syncytin protein, which functions in placenta formation and influences specific brain cells, also originated from a virus. While not yet fully proven, the idea that virus-derived genes may have set humans on a different evolutionary path from other great apes is steadily gaining scientific weight.

So Who Is the Parasite?

By parasite, we mean a creature that unilaterally exploits another’s body or environment — one that only takes, gives nothing in return, and causes harm. Judged by this definition, which group — humans or microorganisms — is actually the parasite?

Microorganisms enrich the soil, decompose dead matter and make it recyclable, add oxygen to the atmosphere, maintain the nitrogen cycle — and even live inside our stomachs, aiding our digestion. Without humans, microorganisms would have thrived for billions of years more. But without microorganisms, how long would humans last?

Humans, on the other hand, have destroyed forests, polluted oceans, pumped carbon into the atmosphere, driven countless species to extinction — and are rapidly exhausting the fossil resources that microorganisms left behind. Is that not a description that fits us rather precisely?

Humans may be intelligent creatures. But if that intelligence was shaped in part by viruses, if the oxygen we breathe is a gift from microorganisms, and if the fuel powering our civilization is an inheritance from microbial bodies — then the claim of being “the finest creation” is nothing but arrogance, not evidence.

This Earth truly belongs to the microorganisms. We are merely guests — and not particularly gracious ones at that.