Edward O. Wilson made his name by arguing that human society and the natural world are governed by the same principles. Sean B. Carroll made his name by unifying the study of humans and animals, showing that development in both is driven by the same fundamental molecular and genetic processes.
So what happened when these two scientists were brought together? They decided to unify all of biology.
Carroll visited Wilson’s office at Harvard University for a free-ranging, hours-long chat. It covered concerns for the future and reminiscing about the past – and morphed into an idea for a global campaign to unite biologists behind the common cause of saving the natural world, a prerequisite for understanding it.
They began their conversation, excerpted below, by discussing the threats to our planet’s biodiversity.
Sean: At what point did you know enough as a scientist, or had travelled enough, that you perceived a threat to nature?
Ed: I knew it when I started going into the tropics in the early 1950s, but it’s the sort of thing you see and you don’t grasp at first. I saw ruined environments in Mexico and parts of the South Pacific, and I used to say, “Oh well, they messed that one up. That makes it a lot harder to go to the rainforest; I have to go way over the mountain range.”
We only began to put the big picture together in the 1970s and 1980s, which allowed us to think in terms of what could be preserved and how we might be able to do it.
You’ve looked at this picture globally – you’re far more experienced than almost any biologist in this – and looked at how large a task this is. Let me make sure I have an understanding of where we would start. Would we start with habitat protection? Is the first job, before we lose anything else, to protect the ecosystem?
Sean: And that’s something people can do.
Ed: Absolutely. That’s what the best global conservation organisations and our government (and other environmentally inclined governments, such as Sweden and the Netherlands) are doing: protecting the remaining wild environment. This is the equivalent of getting a patient to the emergency room – keep them alive and then figure out how to save them.
The global conservation organisations are doing everything they can on modest budgets. They essentially promote setting aside reserves and parks around the world. Recently, in the book Half Earth (due out in March 2016), I’ve made the case for global reserves that collectively cover half the surface of Earth’s land and sea.
Sean: You’ve been very consistent – and persistent – about the importance of inventorying and understanding what biodiversity is out there.
Ed: But the support being given for biodiversity studies and for conservation biology is paltry – it’s a disgrace to the biological sciences. We’ve just about dropped biodiversity studies in relation to all the other environmental sciences, and we’re not pursuing it; we’re not mapping the biodiversity of the earth nearly as fast as we should.
Sean: And why do you think that is?
Ed: Well, the second half of the 20th century was a golden age of molecular biology, and it was one of the golden ages of the history of science. Molecular biology was so successful and made such a powerful alliance with the medical scientists that the two together just flourished. And they continue to flourish.
The students of biodiversity, the ones we most need in science today, have an enormous task ahead of them. Studying model species is a great idea, but we need to combine that with biodiversity studies and have those properly supported because of the contribution they can make to conservation biology, to agrobiology, to the attainment of a sustainable world.
I’ve been too meek. Look at just how few spokesmen there are. It’s hard to name other people who are prominent spokesmen in this area, and we need to get the message across somehow – including through the burgeoning crowd of mathematical-model-obsessed systems ecologists who are flooding into the area. We should make it clear to them, in one way or another, that they’re going nowhere until they know what they’re studying. It’s like having a physiologist in the medical school and you haven’t got the anatomy yet, you don’t know what you’re really –
Sean: You don’t know the terrain.
Ed: Every ecosystem, even a small one, is sustainable because it has certain ensembles and conditions and influences that are unique to it. And the biological ensembles are almost certainly, even the most modest ones, in the thousands of species. We don’t know what’s involved in the models – not even the beginnings. And yet we’re trying to make a sustainable world, which has to include the natural world.
I think that’s the argument I want to make. The human species is triumphant, but it’s got to get a grip. It’s got to come to understand what’s happened, why we’re this way and what we’re doing.
Sean: That’s the reason I took this science education job [at Howard Hughes Medical Institute]. I know five million kids are in biology classes right now, and I want them to be inspired to care about biology. Not the terms in their textbooks, but this branch of science – this branch of human endeavour – that’s closest to their being.
Last spring I gave a graduation address at the University of California, Berkeley, to the molecular biology students there. I concluded my address with a quote from the movie The Graduate: “I just want to say one word to you. Just one word… ‘plastics’.” Then I told them: “I’m going to give you one word now: ‘lions’.”
I asked if they knew that of the lions on Earth 100 years ago, perhaps 5 per cent remain, including very few wild lions outside of preserves. They’ve disappeared – I mean, you can still say they’re wild in the large preserves of East and South Africa, but very few wild lions are left anywhere else in Africa. I’d thought they were protected.
Can you imagine a world without lions or grizzly bears or tigers? Don’t you think, if we suddenly transported ourselves forward in time and that’s the way things were, we’d have to admit that we were utter failures? What’s the point of biology if you have no biology left to study? It would be like a cosmologist looking at the sky and not seeing any stars.
Ed: There are millions and millions of species, including organisms most people have never heard of. There is so much that waits to be told. We don’t know the functions of most of them, but they may be more vital for the planet’s future sustainability than we can even dream. And we have to find out; we need to be doing this sort of study.
Many of the biodiversity stories we see in the news are reports on the destruction of habitats and on species teetering on the brink of extinction. Yet there are places in the world where people have taken action to preserve the natural world, and success stories that we can celebrate and learn from.
Ed: You probably haven’t heard of it, but I’ve been in from the beginning of the campaign in Alabama to create a national park of hundreds of thousands of acres. [The Mobile-Tensaw Delta] would be the most biodiverse park in America, with a tremendous variety of organisms: 350 species of fish and then, to the north, the Red Hills and the Appalachians – deeply divided terrain with relic plants and animals that were left behind during the retreat of the glacier 10,000 years ago. The people down there have just woken up to what we have.
Sean: I was in Yellowstone National Park in August with Liz Hadly from Stanford University, and it still possesses all the mammal species that were there 3,000 years ago. We know this from what the pack rats put into the caves in Yellowstone – and if all the mammals are there, you can feel pretty comfortable that lots of the other things are there too.
So there’s a very old park, a very large piece of ecosystem set aside, it’s enjoyed by four million people a year, but it’s a success story. It says that the first thing you do is preserve a big ecosystem and then manage it. It can be done, and it can be managed scientifically.
It doesn’t mean everything that was ever done in Yellowstone was correct, but I was impressed when Liz explained that she knows that all the mammals that were here before European settlement are still here because she’s done the cave work to look at the microfossils. We should feel good about that: grizzly bears, bisons and wolves are in Yellowstone, and they’ve been removed from almost the rest of their entire range.
Ed: And if you go from the USA – which, relative to the rest of the world, is in pretty good shape in terms of biodiversity and sustainability – to the tropics, everything gets worse. You have Indonesia, which is destroying its own forest. In West Africa there’s no control whatsoever. It’s a global situation. For that reason it ties in clearly with the needs and relationships of low-income countries.
That’s what’s good about Gorongosa National Park, in Mozambique. Don’t let anybody tell you that conservation takes away from the people. I admit it’s a special case, but in Gorongosa you see the truth.
The truth is that one man, Greg Carr, has put a lot of his personal money in it, and he’s been able to save a national forest and start bringing back a little bit of desert. In the course of this, he persuaded the government to include Mount Gorongosa in the park, which captures the monsoon rain and gradually releases it to the whole region. And he’s been able to halt the destruction of the rainforest on the summit, which would have meant in 20 years the entire climate or, at least, the water regime of the area, with all those people living there, would have been changed.
I’ve dedicated my book Gorongosa: Window on eternity to Greg, a “world citizen”. We need more people like him. He and I have talked often about persuading billionaires to adopt national parks. He has furthered the development of the country for these people.
Mind you, this is a country with a very low average daily income. With his own resources, he’s improved schools and clinics all around the park, and he’s got large numbers of people – who were in rags because of the civil war – employed.
Greg also solved the poaching problem, which was severe because the young men in the area had no place to go and no place to get any money, and they were poaching through the park. He got permission from the government to take over the ranger system…and every time they catch a poacher, he gives them a job as a ranger. Last time I went, I met the notorious champion poacher of the area – now a ranger. I shook his hand, and he gave me a great big grin. You know he’s doing a good job.
When researchers discovered that certain genes build the embryos of radically different animals – humans, mice and fruit flies, for example – there was a transformation in our understanding of the relationships between organisms. It launched a new field (‘evo devo’, or evolutionary developmental biology) and brought together scientists from previously distanced biological disciplines. It was, for Sean, a paradigm shift.
Ed: A paradigm shift is the best a scientist can hope for. Whenever I smell an opportunity like that, I go after it. You have a new discovery that something’s working in a different way than you thought. And this is particularly true in molecular and cell biology, which is structural biology and has the least potential for controversy and partisanship among the biological scientists. You’re dealing with a concrete object that’s either there or not there.
Sean: Well, there’s a range of observations and interpretations, and you have to decide which ones are true… That’s what I had experience with, when you’re an early entrant into an area and see there’s some opportunity, and you can’t persuade anybody else. You’re going to have to make it happen and see if there’s something to it.
For example, in 1982 there was a perception among – let’s say – the molecular scientists that if you were going to work on something relevant to human beings, you had to study mammals, or at least something with a backbone. Frogs and chickens, maybe – but they were just a maybe. When I decided I was going to work on fruit flies, many senior figures essentially said, “Well, you’re stepping off the edge of the Earth”. What could fruit flies teach us about the development of things we cared about more, including humans?
But there were a few publications describing fruit-fly mutations that were just too fascinating not to study: mutations that swapped the identity of body parts and mutations that changed the number of body parts, for example. You had to ask, well, how could one gene influence something so striking? That was a great genetic puzzle.
I was in Boston as a graduate student and I heard some talks – just little glimpses of some things – and I made the decision I was either going to work on these genes or I wasn’t going to do a postdoc. I was hell-bent. I’m not trying to give myself any crystal-ball credit here, but there was such a compelling mystery there that I was unwilling to work on anything else.
As it happened, it exploded beyond anyone’s imagination. No one on the planet had predicted that there would be so much in common – that how these genes were connected and working together would be so deeply shared in the animal kingdom. It wasn’t just that the genes were there but that the processes were there, and that what you learn from a fruit fly easily translated.
Ed: That was the paradigm shift.
Sean: Yeah. Driven not by theory, not by foresight, but by data – the sort of data that people were stunned to find and had to wrestle with its meaning. At the time, a relatively small number of labs dealt with these creatures, but four or five years later that was probably up tenfold. It was an explosion of saying, ‘oh my goodness, in fact we can not only find out things that translate but we can find them out a lot faster, a lot cheaper, and this is the tool – this is the passport to the whole animal kingdom’.
In the realm of molecular and cell biology, interest in evolution and the big picture of natural history was muted even through the 1980s. There wasn’t a lot of knowledge, and there wasn’t a lot of curiosity. That, I think, has changed entirely.
Now we realise what living things have in common – processes, molecules, etc. – and it’s had a unifying effect. Biologists have a much more integrated viewpoint and are less inclined to sort themselves into thin slices of disciplines.
I’ll give you an example – I might be known as an evolutionary biologist, but I didn’t meet a palaeontologist until 1994. I was well into my independent career, and I don’t think I was unique. As developmental biology made progress and we were unlocking the secrets of the embryo, it was absolutely natural to me that you’d ask about diversity. But really, early on, most of my brethren in developmental biology weren’t receptive to the idea of a broadly comparative approach to embryology.
What was great was that in evo devo, the palaeontologists were the big cheering section; they gave folks like me encouragement from their exuberance for this field. They weren’t necessarily playing in it, but they were so supportive of what we were trying to do. They were very interested in the evolution of form, for example. This new source of information had them so excited.
A unified biology
To save our planet’s biodiversity, could biologists be brought even closer together and united behind the common purpose?
Ed: Biology has finally opened up to achieve a unifying embrace of all its disciplines. We’re seeing the renaissance of what could be called scientific natural history, which makes available the groundwork – the foundation work – of what is actually on the Earth.
Most people are surprised when they hear my somber figures: we know of 2 million species of plants, animals and microorganisms, and we can give them each a scientific name and a diagnostic description. We know, perhaps generously, more than just a little bit of the anatomy in no more than 10 per cent. We have done thorough studies in fewer than one-tenth of 1 per cent. And the total number of species on Earth is unknown to the nearest order of magnitude.
The invertebrates, including the insects, are clearly undescribed. And now that we’re approaching the microbial world – and we at last have the tools for the rapid identification of species – we could find ourselves in a world of tens of millions of species. That’s a big question that we haven’t even begun to get an answer for: how many species of microorganisms are there?
Now, this is not stamp collecting. What we need is experts totally devoting their research to everything they can find out about every species, in a community of scientists who appreciate that every fact counts…everything new you learn about any species in any group is worth publishing somewhere. It might be a clue down the line for anybody, whether it’s for a molecular geneticist or a developmental biologist or a toxicologist –
Sean: I believe in biology with a big ‘B’. I did a BA at Washington University and the biology department there was a single department, covering everything from wolfpacks to viruses. I really liked that. And then I was a graduate student in Boston, and I didn’t like the tension between the people thinking more about organisms and ecosystems and the people thinking about molecules. Why make a choice? I thought biology was fascinating at every level. Maybe that’s part of what the next generation brought to biology. I certainly felt those barriers were no longer there for a lot of young biologists by the 1990s.
Ed: I think we’re returning to that now.
Sean: But are you frustrated that the biological community isn’t more unified? Just to riff for a minute...now would seem to be the biological community’s moment, whether you work on molecules or on blue whales. And this is our issue: the preservation of biodiversity. The preservation of the health of the planet we depend on as a living species.
This is our existential crisis now. Who knows this situation – and all of its ramifications on agriculture, medicine and so on – better than the biological community? We understand population; we understand evolution.
Look at the way the physics community dealt with atomic weapons after World War II. They thought, “Oh my goodness, look at the power we have.” The nuclear arms race was the great threat to humanity for 40 or 45 years, and it so alarmed the scientific community connected to the technology that many of its leading figures, from Einstein to Pauling to the Union of Concerned Scientists, came together in very public opposition to the bomb. Don’t you think we as biologists, collectively, should be a lot louder and more unified that this is the biggest issue now?
Ed: I do love the way you talk. You’re right – I should have had more imagination. It never occurred to me, as more than just a fleeting thought, that biologists and reseachers from other biological disciplines might be willing to sign on to something similar to the 1955 Russell–Einstein Manifesto.
Sean: Shouldn’t we be on the streets on this one, like the physicists were?
Ed: That’s a great idea. I bet you and I could get an impressive set of signatures if we could compose the perfect statement on what biology must do. “This is the century of biology; this is what biology can give to the world – and this is the kind of broad support it really needs.”
The key word that people have to understand is ‘sustainability’. We have to create a sustainable environment, worldwide, and we’re not doing it. The best thing we can do with the rest of this century is aggressively acquire – and put aside – the richest natural reserves that we can, and then do our best to manage the needs and desires of the 11 billion people we expect to have by the end of the century.
This is where biology is headed. For that reason, the sooner we get on with mapping biodiversity on Earth, the better off biology will be – not to mention the whole subject of saving it before we carelessly throw it away.
This conversation originally appeared on Mosaic Science. It has been republished with permission.
Images via NASA’s Visible Earth collection.