For evolutionary biochemist Professor Nick Lane, the big questions of how life began, evolved and developed have a very specific focus.
“I’m coming from an energy flow point of view,” says the researcher, writer, and Professor at University College London.
“I’ve always been intrigued by this weirdness, that cells are powered by an electrical charge on a membrane, and that charge is massive. It’s equivalent to 30 million volts per metre, across this membrane, and that powers all of life. It just seems amazing! Why would it be like that?”
The impact of this electrical charge, from powering individual cells to the resultant functioning of the human brain, will be the focus of Lane’s Darwin College Lecture this Friday.
“I’ve been interested for a long time in how did that start, in the beginning, at the origin of life, and what effects did it have on the history of life? And probably the biggest one which I’ll talk about, although I’ll talk about a few other revolutionary moments as well, is the origin of the eukaryotic cell, which is our own kind of cell, which has a nucleus and has all kinds of stuff going on inside, including mitochondria. We often call mitochondria the power packs of cells, but they were bacteria once, they have this electrical charge on their membrane. Effectively we internalised the power packs, we internalised this charge, along with the genes that control it. And that’s something that seems to have happened once, in the whole history of life on earth. I mean, if there’s anything you could call a revolution that was it.”
The talk will also explore how the evolution of photosynthesis had a transformational effect on the planet, while pointing out the chemical overlaps between processes which otherwise appear quite distinct.
“In a strange way there’s some chemical gradualism to it, but there’s a huge revolution in terms of the consequences. So I’m going to be taking a non-genetic take, if you like, on the history of life on the planet.”
The inclusion of ‘non-genetic’ is necessary here because, Lane believes, genes have become so predominantly the lens through which life is understood.
“Genes are so central to the way we think these days that we’ve come to the point where we tend to have a kind of unquestioned assumption that genes direct evolution, they direct the way that things happen, and that they invented everything. And I would see it the other way up, that there are natural geochemical processes that give rise to biochemistry, that give rise to genes, which effectively stabilise the processes and allow them to happen outside that environment. So I suppose what I’m getting at is that there are other things in biology than genes – the cells and the way in which energy works in cells, and the core chemistry of cells, and when you see evolution from that point of view, then these big apparent revolutions that look like genetic revolutions, like the origin of photosynthesis and the abrupt appearance of animals and the Cambrian explosion, make much more sense.”
Lane’s research is now largely focused on the origins of life, a subject which naturally leads to the consideration of how likely life is to exist beyond earth. The basic requirement, in his view, is “a wet, rocky planet.”
“You need water, you need minerals like olivine, which give rise to hydrogen gas, and you need CO2, and that’s about all you need. So there are probably tens of billions of wet rocky planets in the Milky Way alone. And if that’s all you need to give rise to bacteria, then there should be life everywhere. But then there’s the question of why it took so long on earth to get past bacteria. I don’t personally think that simply exploring genetic sequence space – in other words all the possible combinations of genes that you could have – is enough by itself to give rise to complex life. What you need is some change in structure which permits a different direction in evolution. That’s what happens during the evolution of eukaryotes.”
Lane combines his research with a successful career as a science communicator, as the author of five books and a regular speaker and broadcaster. The two elements of his working life are mutually reinforcing, as communicating his work compels him to revisit it in a different light.
“I love trying to communicate with the general public, partly because it’s a pleasure doing so, partly I genuinely care about the place of science in society and would love people to know and understand why scientists care passionately about what we do. But also, I’m trying to understand it myself, and I find that if you try and understand it in technical terms, somehow there’s a veneer across the top that means that you don’t see the obvious flaws in an argument. So for me, the thrilling thing about attempting to communicate is that I can see all the holes in my own argument by trying to make it clear to someone who’s outside and wants to know.”
The audience Lane has in mind is based in large part on his 16-year-old self, an age when he remembers being deeply drawn to science writing and the sense of science as a work in progress that it opened up.
“I think people would be much more excited about science if they realised that it’s not ‘learn these facts’ – it’s really what we don’t know, and how can we think about the things that we don’t know, and what do we know, and do we really know that! And I suppose when I was 16 I was excited by books that felt on the edge of evolutionary biology at the time. This was the time of Richard Dawkins’ The Selfish Gene, which was an emotionally devastating book. I didn’t like this view of life, of us as blind robots driven by selfish genes; it’s a bleak view and I was very happy to find people arguing against it in ways that I hadn’t thought of. I could see flaws in their arguments, but this idea that science is an argument, that it’s grounded in evidence but that there isn’t a single answer, I think I got from reading books when I was about 16. I think looking back on it, what made me excited about science was the books being written by people at the edge of knowledge, arguing between themselves passionately, but courteously, about what that meant.”
Nick Lane’s lecture, Revolution by Natural Selection: A radical history of life from inside our cells, will take place at 5.30pm on Friday 1st March.
