Music: Variations on a Theme by Giuliani
Rissa de la Paz: Hello and welcome to the first of our monthly podcasts for Darwin Now. This year marks a special double anniversary: 200 years since the birth of Charles Darwin and 150 years since the publication of his most famous work, The Origin of Species. In the UK alone, there will be no shortage of media events, conferences, books and articles to celebrate the fact. Indeed, the British Council’s Darwin Now project is one of the fruits of such initiatives.
Why the frenzy of activity? What lies behind Darwin’s enduring appeal? We posed the question to Steve Jones, Professor of Evolutionary Genetics at University College London, and himself an author of a series of books aimed at updating Darwin for the modern audience. He shared his reflections via a computer link.
Steve Jones: I think Darwin was special really because he invented a science, he invented the science that we now call biology. Of course there were lots of people working on flowers or digging up fossils or breeding sheep and cattlebefore then, but none of them realised that they were actually doing the same thing. But what Darwin did was to show that, to show that there was a kind of unitary theory, evolution, which united all that material. I often think that his theory is in some ways the grammar of biology. You can’t understand the language, you can’t speak a language unless you understand its grammar, either consciously or subconsciously, and you can’t be a biologist unless you understand evolution. So I think it’s an anniversary well worth celebrating.
Rissa de la Paz: What was the crux of Darwin’s ideas?
Steve Jones: Darwin described his own theory in a pretty tight nutshell. Evolution, he said, is descent with modification. Descent, the passage of information we’d say today, from one generation to the next, and modification, the fact that that passage is imperfect. Over time those changes will build up and you will get change. It’s inevitable, it’s bound to happen. But we can rephrase that in slightly more telling terms today. We can say evolution is genetics plus time. If you’ve got genetics, DNA and all that stuff, if it copies itself with mistakes, that’s mutations, and if you’ve got time, and we’ve got three and a half thousand million years since the origin of life, evolution is absolutely inevitable. So that’s the core of Darwin’s theory. It’s extraordinarily simple.
But Darwin had a second idea, and that’s really where he was so smart because he realised that what’s being copied in biology is itself a copying machine so that if one version inherits a change, a mutation, which makes it more likely that it will survive and reproduce itself, then that change will become more common and will spread, and over time those differences will build up and new forms of life will emerge by what he called natural selection, inherited differences in the chances of reproducing. So that’s Darwinism in one minute.
Rissa de la Paz: No doubt something that would have surprised Darwin is the fact that we can actually see evolution in action, even within our own lifetime. A spectacular example of this is the evolution of disease, particularly HIV/AIDS.
Steve Jones: What’s remarkable is that you can see Darwin’s natural selection, inherited differences in the chances of staying alive hard at work. We’re pretty clear now that HIV only began to spread from isolated villages in Africa in about 1910 or so, when the first African cities began to grow and began to get big enough to sustain an epidemic, and it got into the West in 1979 and became a global epidemic by the end of the eighties.
It was pretty soon found that some people were doing much better when infected with the virus than were others. The way the virus works is you become infected and the virus then begins to hijack and destroy the white blood cells that control your immune system. It gets in by attaching itself to a particular molecule on the surface of the white cells, and it can take years before any symptoms show themselves, and the symptoms begin to happen when the immune system is finally breaking down. And it pretty soon became clear that some people were infected and really doing very well. Their immune systems were in good shape ten or fifteen years after they’d picked up the virus, and that turned out to be due to the fact that they just by chance had inherited a particular version of that attachment side on the surface of their white blood cells to which the virus could not stick. It couldn’t get in. So they were infected but they didn’t suffer very greatly from the effect.
Other people didn’t have that. The virus got into the blood stream and infected all their white blood cells very quickly, and so they died quickly. And that’s a beautiful – and I use that word advisedly – that‘s a beautiful example of Darwin’s natural selection in action. And it goes further than that, because if you look at Africans who’ve been exposed now for several generations to HIV, it turns out that many more of them have got multiple copies of that protected gene than Europeans, who’ve only been exposed to HIV for one or two generations. And even if you stand further back from the problem and look at chimpanzees – and that’s where the virus came from – they’ve got many, many copies of this gene and there the virus causes them no harm at all. So that’s almost a perfect example of natural selection in front of our eyes with, as proof of its action in the past, our friend the chimpanzee, who gave us the virus in the first place, has evolved through the whole system and now can resist the virus entirely.
Rissa de la Paz: The evolutionary tug-of-war between pathogens and their hosts is repeated time and again across the plant and animal kingdoms, with direct consequences for human welfare. Take the rise of antibiotic resistance in bacteria, or pesticide resistance in plants. Fern Elsdon-Baker, an historian of science with a background in environmental studies, argues that evolution can offer insights into yet more of today’s most pressing concerns.
Fern Elsdon-Baker: There are lots of benefits to understanding evolutionary theory, not only the understanding of how species evolved over time, but also how they interact with environments around them.
One of the debates that’s been going on for the past 150 years involves what level natural selection happens at. For Darwin it happened at the level of an organism. For thinkers in the late 20th Century it happened at the level of the gene. Today we’re beginning to think more about how the gene, the organism and the environment interact. This is going to be of tantamount importance, especially when we think of the impact of global climate change. What is the role of the environment in evolution? How will changes in the environment impact on future species?
Rissa de la Paz: It was actually through studying the links between ecology and evolution that Elsdon-Baker herself was drawn to Darwin.
Fern Elsdon-Baker: What really brought me to Darwin was that when I was an undergraduate studying environmental sciences, I started to study evolutionary ecology – how organisms interact with each other, and how this can affect them in the long term. I then became interested in the history of Darwinism, and really started to wonder about how the ideas in Darwinism and in evolutionary theory had changed over time themselves. One of the things that fascinates me, and still fascinates me about Darwinism, is that there is this dynamism, there is this discourse, there is this debate. While obviously we’re celebrating the great man Darwin in 2009 he wasn’t a lone voice in the wilderness, he was part of a wider scientific community with a number of fluid ideas about how the world works. I find this fascinating. I find the historical discourses and the way they run right up to present are alive with different characters and people, and Darwin is one of those.
Rissa de la Paz: We’ll be exploring the context in which Darwin developed his ideas in later podcasts. We shall also be looking at the ways in which our understanding of evolution has itself changed. Have developments in genetics and our unravelling of the structure of DNA itself vindicated or demolished Darwin’s original ideas? Steve Jones.
Steve Jones: Charles Darwin was, among his many talents, a great anatomist. He spent eight years cutting up little tiny barnacles under the microscope, as many people don’t know. That skill has been lost many people say, but of course it hasn’t, it’s just been reinvented, it’s called molecular biology. And that’s what the study of DNA sequences is, it’s anatomy. It’s just comparing the structure of creatures in the way that Darwin compared the structure of barnacles, but using the fundamental underpinning of all anatomy, which is the double helix. And what it’s done is to build on the foundations laid by Darwin and his predecessors to show that we belong to the same shared family.
We share about something like 95% of our DNA sequence with chimpanzees, something a bit less with orang-utans, and for that matter about 50% of our DNA with bananas, which is exactly what Darwin would have predicted. It’s shown how much the creatures of the world, speak the same language.
It’s a cause of amazement to me that people are not amazed by the fact that you can put a human gene into a bacterium and manage to persuade it to make a human protein, and that’s now done, not exactly routinely, but widely to make things like insulin, to make things like human growth hormones. Why should that be except for evolution? Only because we descend from the same ancestors as bacteria can we take one of the cogs in the gigantic machine that makes humans work, and insert it into the same place in the smaller machine that makes bacteria work, and make it turn around, and that’s amazing really. And that’s what comparative genomics, as it’s called, has really done. It’s moved humans off the pinnacle which they felt they occupied as being different from the rest of the living world and said there’s nothing special about you, at least when it comes to DNA.
Rissa de la Paz: The journey from Darwin to DNA and beyond is just one of the avenues that will be explored as part of the British Council’s Darwin Now project. Fern Elsdon-Baker outlines the vision behind the initiative.
Fern Elsdon-Baker: The British Council Darwin Now project is really an opportunity for us to engage with different audiences on an international level. It’s really looking at the historical Darwin and bringing him right up to date in the 21st Century, giving people the information and the tools to understand for themselves the simple and beautiful theory of natural selection that Darwin put forward.
We will be organising lots of different events and activities in order to let people engage with the science behind Darwin. These will range from things like public lectures or more informal seminar-style type events like Café Scientifiques. There will be an international exhibition which will be running in a number of countries concurrently. There will be online versions of the exhibition, online educational materials, educational materials available for schools.
Rissa de la Paz: An important aspect of Darwin Now is its global scope and reach.
Fern Elsdon-Baker: We’ll be involved in a number of Darwin-related activities all over the world in 2009. We’ll also be allowing international audiences access to UK-based events. For example, we will be having informal café-style linked events relating to the Darwin Cambridge Festival. We will be bringing students to an international student summit at the Natural History Museum in London. We’ll be taking UK speakers out to international Darwin public lectures, seminars, workshops. We’ll also be having a lot of web-based activities including obviously this series of podcasts.
Rissa de la Paz: The activities are designed to reflect the main themes of the project. One of these is Evolution for all.
Fern Elsdon-Baker: Evolution for all is really an opportunity for audiences at all levels, all age groups, all nationalities to find out for themselves that Darwin’s theories are actually beautiful in their simplicity. So really Evolution for all is a series of different events and activities to bring people in and give them the tools to understand evolution for themselves.
The British Council is partnering with the Wellcome Trust and the Botanic Gardens at Kew. We will be internationalising some of the educational materials that they have been developing for the Darwin celebrations. They range from mucky hands-on experiments to debate activities, to really explore the core concepts and ideas.
We’re really trying to bring together a mixture of audiences and reallyimpassion people about the exciting elements of Darwin’s work, and how Darwin’s work is being explored today.
Rissa de la Paz: The second theme of Darwin Now is Challenging Controversy.
Fern Elsdon-Baker: Challenging Controversy really is a way of us exploring what science is. Science is a dynamic process based on observation and experimentation. It’s about discourse and debate between international communities. It always has been. In Darwin’s day he corresponded with over two thousand people. There has been through the 19th Century, the 20th Century, right up to the 21st Century much debate and discussion about how evolution works. This is one of the beauties of science. It’s a dynamic process.
Rissa de la Paz: It’s this vibrant interplay between science and social context that we aim to reflect in the podcasts and other online resources we’ll be offering you as part of Darwin Now.
Fern Elsdon-Baker: Some of the things that we can really look forward to in the series of podcasts and other web broadcasts that we’re putting together for Darwin Now really will be the opportunity to explore not only Darwin in his context – so Darwin the scientist, the thinker, the man, the communicator – but bring Darwin out of the 19th Century and bring him through the 20th Century into the 21st Century, really putting him and his theories within a global context, looking at how Darwin is still important to all of us today. How our understanding of evolution impacts on our understanding of ourselves. So Darwinism and evolutionary theory are important not only for scientists, but they give us an insight into the natural world that have inspired many people over the years, from writers to artists to dancers to poets. There are many different ways of expressing and understanding humans’ role within nature.
Rissa de la Paz: The relationship between human beings and the rest of the natural world was an area of lively debate even in Darwin’s time.
Steve Jones: I think one of the reasons that so many people in 1859, the time of The Origin of Species, were so worried about Charles Darwin’s theory of evolution, was that it seemed to knock humankind off some kind of special pinnacle upon which it had been placed by God. Everybody thought, and it’s a not unreasonable thing to imagine, that humans were entirely different from everything else. Queen Victoria went to London Zoo once and was quite shocked by the orang-utan because it seemed to her, I think she said painfully and frightfully and disagreeably human.
Well now DNA tells us that we’re really in physical terms not special at all, but to me actually that makes me feel as a human being, far, far more special than I ever thought before I knew about evolution. Because I know that everything that makes us human is unique. The sense of consciousness, for example, the willingness to look ahead, perhaps for many hundreds of years ahead, an understanding of history, speech itself – the fact that we can communicate complicated ideas to ourselves – curiosity, the ability to teach. All these things are absolutely unique to ourselves, and that to me, combined with the fact that we share so much of our DNA with apes, tells us not that we’ve been knocked off a pinnacle but that we’re actually on a pinnacle far, far higher than we thought we were on before Charles Darwin did his work. We’re far more special than we thought in all the ways that matter, and those ways are not necessarily in the DNA.
Rissa de la Paz: So can the combined tools of genetics and natural selection shed any light on those characteristics that do make us uniquely human?
Steve Jones: There’s a new affliction which is now spreading through the world of the intellect, which I sometimes think of as Darwinitis. It’s the idea that Darwin’s notions explain everything about ourselves – about politics, about society, about the relationship between the sexes, about parents’ interactions with their children.All these things can be explained by Darwinism.
I think we need to be very cautious. Having said that, of course, there are many, many cases where our own individual mental fate is controlled by our genes, and as a result by our inheritance, by Darwinism. The vast majority of people in long-term mental homes for example, are there for reasons which we more or less understand, to do with errors in their genes. We don’t know why the errors are there, but it’s a biological error,and maybe evolution will help us to comprehend what’s gone wrong. There are some cases, it’s pretty clear now, for example, that some people have genes that predispose them to addictive sorts of behaviour, so that if you drink alcohol, let’s say, you find it much more enjoyable than people with different kinds of genes, and so you’re much more liable to become severely addicted and damage your health.
So I think Darwinism is beginning to say a little bit about individual differences among ourselves in a way that we didn’t understand before. What it’s not doing, and I really think this is true, is saying anything very interesting about what makes us human rather than just another primate, just another animal.
Rissa de la Paz: We’ll be exploring some of the unique aspects that make us human – such as language – later on in this series of podcasts. What certainly stands out is our remarkable growth as a species.
Steve Jones: We’ve become grotesquely abundant, humans as a species, simply because of our mental prowess and the way we stood outside the laws that control all other animals. We’re about ten thousand times more common that we “ought to be”, in inverted commas, if we were just another primate like a chimp or orang-utan living in nature. Now when you get that common, things are getting pretty dangerous, and we’ve seen it happening because of disease. Because if you’re a species that’s tremendously abundant, constantly meeting other members of its own species, constantly moving around, is at risk of epidemics, and it’s no mistake that we had huge epidemics, for example, the Black Death and so on. HIV AIDS has spread with air travel, and no doubt many more epidemics are waiting just out there. So that may be something we can’t do anything about, and then you’ll see evolution, Darwin’s natural selection, really coming into play with a vengeance.
Rissa de la Paz: The consequences are sobering, as we can already see from the fate of other species.
Steve Jones: Most species in the end go extinct. There aren’t many sabre tooth tigers left any more, and I’ll make another prediction, which is that by the time of Charles Darwin’s 300th anniversary of his birth, there will be no wild big primates left at all. There’ll be no chimpanzees, no orangs, no gorillas, or if there are any they’ll be in zoos. They’ll be extinct.
Now that’ll be very, very sad but you’ve got to bear in mind that there have been hundreds and hundreds of other cases of wild primates which have gone extinct. In fact, if we look at our own living family, the family homo, homo sapiens is our Latin name of course, we’re actually living at a unique moment almost, which we’re the only member of our family that’s alive. Even thirty or forty thousand years ago we had Neanderthals who are quite close to us, and if you go further back, there are often several different kinds of humans living at the same time, all of which have gone extinct. So, for us I think extinction will happen too, but I hope not too soon.
Rissa de la Paz: How our own evolutionary story unfolds will depend on how mindful we are of what we’ve learned so far. But looking back on the past hundred and fifty years, how have Darwin’s original ideas fared?
Steve Jones: I think Darwin’s theory of evolution has stood the test of time extraordinarily well. In some ways it’s provided the steel framework of an enormous building, an edifice, to which we can now bolt all kinds of apparently unrelated facts, and now we’re in the business of building almost a skyscraper called biology, because we have this mass that holds it all together. Certainly there were plenty of holes in Darwin’s theory in his time, there are difficulties today. Darwin himself saw some of those difficulties – inheritance, how old was the earth, could you explain behaviour through evolution, and why were the sexes so different. He saw these difficulties and he didn’t get it all right. But looking back, 150 years later it is quite astounding how well his theory has held up.
I have to say, though, as word of warning, which I think is an important word of warning, in 1905 physicists were saying that, looking back on the world of Newton, long before Darwin, it was quite astounding how his world had held up, that we understood the entire universe in terms of Newton’s laws of action and reaction and so on, and it was wonderful and Newton had done so much, somebody said, in fact, that physics was finished, there was no more to be done. Then later in that year people began to notice that different elements if you put them in a flame, burned yellow or purple or green, and from there came the notion of quantum change, uncertainty, relativity, and physics fell apart and they had to start again. Well that hasn’t happened to evolution. I don’t think it’s going to happen to evolution, but if it does happen to evolution I’ll be the first person to cheer.
Rissa de la Paz: Healthy scepticism and a readiness to test and refute theories is the very essence of doing science. For Steve Jones, that means guarding against the worship of scientific idols.
Steve Jones: My biggest hope for the end of 2009, the end of Darwin year, is an odd one, which is that Darwin will at the end of it look less important than he did at the beginning. And I mean that for a rather specific reason. If the biologists of the world, the scientists of the world, the science communicators of the world, can persuade the public that evolution is only a science, it is not a panacea that tells us what we are and why we’re here, it is not an insult to religion, it is not a cure for our doubts about our future, and if people realise that Darwinism is only a science and that Darwin himself was only a scientist and not a prophet, at the end of this year I shall be a happier man than I am at its beginning.
Rissa de la Paz: And on that note, we end this month’s podcast for Darwin Now.
Music: Variations on a Theme by Giuliani – duration: 00:18
Rissa de la Paz: The podcast was produced as a collaboration between the British Council and the Open University.