futurology
Ascending
Life
International Life speaks to leading biochemist and writer Nick Lane about his inspirational and awe-inspiring book on the wonders of life and how it arose. A masterpiece of popular science that communicates complex ideas simply, our only warning is that reading the book may make you look more intelligent than you are.
What inspired you to write Life Ascending? The desire to know! Scientists want to know the answers to the same questions as everybody else. Why are we here? Why is the world the way it is? Research is so focused you lose perspective. The great thing about writing books is that you go back to the big questions that led you into science in the first place. How do you think life started on Earth? Life arises from a ‘living’ planet. Our obsession with genes makes us lose sight of the difference between a living thing and a dead body. The difference is the flow of energy. Life started because the planet sets in motion exactly the same flows of electrons and protons as in a living cell. Stop the flow - put a plastic bag over your head - and you cease living. How much closer are we to understanding how DNA works? We understand very well how DNA works, in the limited sense that we know how genes code for proteins. Yet even though
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most of the human genome doesn’t code for anything, it is not junk DNA. This ‘dark matter’ of the genome works in ways that we are only just picking at. Why is sex better than cloning? Sex frees genes. In clones, all your genes are in it together, in the same combination, forever. They can never mix and match in a new body. Mixing and matching is just as likely to come up with bad combinations as good ones; but natural selection eliminates the bad combinations, leaving just the good ones. Can you describe how photosynthesis works? It uses the energy of the sun to split water into hydrogen and oxygen. The hydrogen is bound onto carbon dioxide, to form organic molecules, and oxygen is released as waste. Animals do the reverse, so life is a kind of ‘futile cycle’. All our energy is a beam of sunlight set free from its captive state in food. Would it ever be possible or worthwhile to engineer human cells to photosynthesise? It would be possible, but not worthwhile. To generate enough energy even to walk around you’d need the surface area of a tree. A ‘green man’, powered only by photosynthesis, would be barely able to move his little finger. Are we close to cheaply synthesising photosynthesis; the splitting of hydrogen and oxygen in water to create a hydrogen economy? Surely not far! Photosynthesis splits water using a tiny mineral cluster of manganese
and oxygen atoms. In cells a lot depends on the proteins that surround this cluster; but we should be able to make a similar cluster that splits water and bubbles off hydrogen as soon as you put it in gentle sunlight. The real challenge is overcoming vested interests. You talk about human consciousness, what progress has been made in understanding how our brains actually function at a cellular level in the last few years? Very little, in my view. Human consciousness is enormously complex, but in conceptual terms that is simply complexity. The difficulty remains the mind-matter problem. How does a neuron firing give rise to a feeling of anything at all? I don’t know; but at this level of feelings I’m sure that bees are conscious. So the answer lies in simpler organisms. You discuss ageing and how some Japanese men with a single DNA variant often enjoy good health well into old age, what advances are we making in extending lifespan and health span? We are tantalisingly close and distressingly far. There’s no greater human tragedy than the degenerative diseases of old age. Evolution says we can fix them, and we’re beginning to see how, but the juggernaut of medical research insists on treating different diseases as independent problems, and ageing as normal. They’re not. What project are you working on next? A book on my research - why the origin of all complex life looks like a freak accident.