Nick Lane on the Origin of Life, Bioenergetics, and Why Complex Life Is Rare

Nick Lane, biochemist at University College London and author of The Vital Question, Life Ascending, Power, Sex, Suicide and Transformer, argues that life is best understood not as information but as energy. Life began, he holds, where a wet rocky planet leaks hydrogen — at alkaline hydrothermal vents that supply ready-made electrical gradients across mineral pores. From that single starting reaction he traces a chain of rare inventions: photosynthesis, the complex cell, sex and death. The complex cell, he contends, arose exactly once on Earth, which is why a galaxy teeming with bacteria may hold almost no one to talk to. The conversation runs from that origin through consciousness, AI, the Fermi paradox and how to write — and how to live.

Key ideas

1. Life began at hydrothermal vents, not in a soup. A wet rocky planet vents hydrogen gas across mineral pores that already carry electrical charges. Those charges drive the reaction between carbon dioxide and hydrogen — the same reaction at the heart of living biochemistry. Lane rejects the ‘primordial soup’, because a soup has no structure and no continuous flow; a vent gives self-organisation and growth from the very beginning, with no miraculous moment when chemistry ‘goes alive’.

2. Bioenergetics is the deep constraint on life. Living things are powered by electrical charge across membranes — a continuous chemical reaction, not a one-off Frankenstein spark. The early Earth is itself a giant battery: reduced iron and electrons at the core, oxidised gases at the surface, electrons flowing between them. A cell is a micro-version of that planetary topology, which is why Lane thinks the chemistry, and even the genetic code, may be close to inevitable on any similar world.

3. The complex cell arose only once, by one cell swallowing another. For its first two billion years Earth held only bacteria and archaea — small, simple-looking cells with no nucleus. Then, once, one cell got inside another (an endosymbiosis). The engulfed cell became the mitochondrion, the cell’s power pack, shedding nearly all its genes while keeping the energy machinery. That asymmetry — a huge nuclear genome supported by many stripped-down energy units — let genomes grow roughly a hundred-thousandfold. It happened once and has not recurred, which is why Lane thinks it is genuinely hard.

4. Sex, death and complexity come as a package. A large genome must be defended against mutation, which forces eukaryotes into sex — fusing cells, lining up chromosomes, recombining, then dividing twice. Programmed cell death, the same machinery that sculpts our fingers and synapses, also appears across complex life. Death is not incidental to evolution but its engine: ‘evolution only happens because of death.’

5. Complex life is probably rare; bacteria probably are not. Run Earth a million times and Lane expects bacteria a few hundred thousand times — but the jump to complex cells, photosynthesis, animals and intelligence stacks improbable bottlenecks. So the galaxy may hold tens of billions of bacterial worlds and almost no one to converse with. His Fermi-paradox answer is the plainest: advanced minds simply do not exist in the right part of the universe at the right time.

Content

Why a vent, and not a soup

Lane starts from a biologist’s question that origin-of-life chemistry, he says, has long skipped: what does life actually do? It is made of carbon, built of cells, and powered by electrical charge on membranes. Ask where on the early Earth those exact requirements are met, and one environment answers — the hydrothermal vent. Wherever water meets rock, the planet vents hydrogen ‘in bucket loads’ across cell-like mineral pores that already hold an electrical charge. That charge drives the core reaction of life: strapping hydrogen onto carbon dioxide to build organic molecules. Run that reaction in the lab and the molecules you get are ‘exactly the molecules that we see at the heart of biochemistry’.

This is why he dismisses the primordial soup — the idea that amino acids and nucleotides, perhaps delivered by comets, simply accumulate in a pond and one day come alive. A soup, ‘almost by definition’, has no structure; a vent gives a continuous conversion, a flow of molecules turned into more of yourself. There is no moment when something inert goes ‘bloop’ and becomes alive. (Panspermia — the theory that life, or its ingredients, arrived from space — he finds unhelpful rather than wrong: even if true, it only relocates the question of how life starts on any planet.)

There is, he stresses, no single spark. We imagine Frankenstein: one zap and it lives. But what keeps a living thing going is a continuous chemical reaction — for us, breathing oxygen; put a bag over your head and you have about a minute. The ‘spark’ at the origin is merely the continuous electrical charge that pushes hydrogen and CO₂ over their kinetic barrier. Thermodynamically, two gases are less stable than cells: the cells are what ‘should’ come out, given a catalyst and a charge.

LUCA and the deep split in life

All life shares a single common ancestor — LUCA, the Last Universal Common Ancestor — because the genetic code is identical across every organism. Yet life’s deepest division, between bacteria and archaea (which look alike under a microscope but differ fundamentally in their membranes and DNA-replication machinery), tells Lane that life probably arose only once. His picture: millions of vents, millions of candidate ancestors, but one lineage gets out first, takes over the world, and wipes out the rest. Curiously, two distinct cell types seem to have left from the same vent — they share the code but diverge sharply the moment they must power their own membranes outside the vent, each evolving a different ion pump, and from that the rest of their biochemistry diverges.

Prokaryote and eukaryote are the two grades of cellular life. A prokaryote (bacterium or archaeon) is a small cell with no nucleus. A eukaryote — us, plants, fungi, amoebae — has a nucleus and an interior crowded with machinery. Bacteria emerged some four billion years ago, dominated the planet fast, and ‘haven’t really changed’: ‘four billion years later they look exactly the same.’ Something stops them becoming complex, and it is not lack of opportunity or time.

The information problem is really a structure problem

Bacteria have explored genetic space far more thoroughly than eukaryotes ever did — a single E. coli cell can draw on a ‘metagenome’ larger than the human genome, swapping genes laterally like loose change, across populations vastly larger and twice as old. And still they remain bacteria. So the barrier to complexity is not information; you cannot solve it with genes alone. The problem is structure, and specifically energy.

The first cells needed an electrical charge across a membrane to grow. In bacteria that charge sits on the outer membrane wrapping the whole cell. Scale that up and you hit an engineering wall: giant bacteria can only carry tens of thousands of copies of their whole genome (extreme polyploidy), which is ruinously expensive and leads nowhere. The eukaryotic solution was to move the charged power units inside — bacteria living within the host cell — each keeping its own small control genome. That changes the cell’s topology: one giant nuclear genome surrounded by many subsidiary energy genomes. The same amount of DNA, but now an asymmetry that frees the nucleus to grow.

Why the complex cell is the great bottleneck

The mitochondrion — the cell’s power pack, a former free-living bacterium now reduced to as few as 37 genes — is, in Lane’s reckoning, ‘the single biggest invention in the whole history of life’. Genes went up roughly fourfold; the energy available to express them went up a hundred-thousandfold. That is the change that made large genomes, and therefore plants and animals, possible. Multicellularity needs a single founding cell carrying all the genes, switching different sets on in brain, liver and so on; bacteria never get enough genes into one cell, and bacteria of different types brought together to cooperate simply fight instead.

It took two billion years and has not happened since — strong evidence that it is genuinely difficult. Lane is candid that this leaves a bleak fork: either endosymbiosis is nearly inevitable once one cell takes up another, or it is a near-impossible fluke that usually ends in conflict, death and extinction. ‘Both of them are a bit grim,’ and we do not yet know which is true. Either way, without it ‘life on earth would be bacterial only’ — which is the heart of his case that complex life is rare.

Photosynthesis, oxygen, and the rise of animals

Oxygen-producing photosynthesis was another singular invention, achieved only by cyanobacteria. Splitting water to harvest hydrogen takes enormous power and exquisitely careful ‘wiring’ to stop the separated charge rushing back as an explosion — which is likely why it happened once. Its waste product, oxygen, Lane calls ‘the single greatest planetary pollution event in the whole history of the earth’. That pollutant made large active animals possible: oxygen lets an organism extract about 40% of the energy in food rather than roughly 10%, supporting the five or six trophic levels of a real ecosystem and the predator-prey arms races of the Cambrian explosion.

Consciousness: the real mystery in biology

Intelligence Lane treats as a form of computing — extraordinarily complex, but not logically mysterious; AI already rivals and will exceed human information-processing. The mystery is feeling. ‘How does a discharging neuron give rise to a feeling of anything at all?’ He finds panpsychism (everything is conscious) unpersuasive and ‘emergence’ too often a word that plasters over ignorance. His own speculation reaches back to the electrical fields on membranes: a single cell acts as a unit with astonishing precision, and those real-time electrical signals of ‘how am I doing in my environment’ may be where feelings enter ‘through the back door’. Biology, unlike society, carries a death penalty over every decision — and that lived stake, selected over generations, is what Lane suspects is hard to simulate. Whether a sufficiently complex AI would feel anything, he leaves genuinely open, and suspects consciousness, if solved, will be solved by an outsider to biology.

Aliens, AI, and the Fermi paradox

Because the chemistry and code may be near-inevitable, Lane expects bacteria to be common and would be most interested, in any Martian life, in how similar its code was — only opposite stereochemistry (a mirror-image molecular handedness) would prove a truly independent origin. But the bottlenecks above make intelligent, space-faring life rare. His Fermi-paradox answer needs no exotic filter: such minds simply are not here, now. He doubts a sterile planet can give rise directly to AI without first evolving organic life as the intermediary — and doubts, soberly, whether humanity will survive its own next century, with AI perhaps the part of us that carries on. Asked to summarise Earth in the manner of the Hitchhiker’s Guide, his first word is ‘living’ — profligate, rich, ‘enormously living’ — and, on a cosmic scale, still ‘mostly harmless’.

Related

• Lee Cronin on Assembly Theory, the Origin of Life, and Alien Detection — same question, a rival framework: assembly theory and a chemistry-first route to detecting life
• Sara Walker on the Physics of Life, Time, Complexity and Aliens — life as physics, complexity and the search for alien life
• Adam Frank on Alien Civilizations, the Search for Life, and Technosignatures — the abundance and detectability of life, and the Fermi question
• Michael Levin on Bioelectricity, Basal Cognition, and Diverse Intelligence — bioelectricity and development; Lane cites Levin’s planarian work directly
• Sean Carroll on General Relativity, Quantum Mechanics, Black Holes and Aliens — complementary cosmological and philosophical framing of life and the universe
• Lex Fridman — host