Smithsonian magazine’s Lyn Garrity spoke with Wallace expert Andrew Berry about the naturalist. Berry teaches evolutionary biology at Harvard and is the author of the book, Infinite Tropics, an annotated anthology of Wallace’s writings.

How did Alfred Russel Wallace come to be a naturalist?

He grew up poor, was taken out of school very early because his family couldn’t afford it. He apprenticed at a young age to his brother, a railway surveyor. This is in the 1830s and 1840s when railways were springing up across the United Kingdom, and to be a surveyor was a good way to make a living. During this time, Wallace became interested in natural history in a completely self-taught way. When the surveying business died briefly, he took a job as a teacher in the town of Leicester and this was his big break. He met a man called Henry Walter Bates who was also very young at the time, around 19, and already a published beetle expert. Bates transmitted the beetle-collecting virus [enthusiasm], if you like, to Wallace.

These young kids read this slightly dubious but bestselling popular potboiler with evolutionary ideas called the Vestiges of the Natural History of Creation that came out in 1844. (The book was one of the reasons Darwin delayed publishing for so long because it was pilloried by the scientific establishment.) Then in what I find mind blowing, these two, who’ve never been out of England or anywhere, conceived this idea of going somewhere beyond Britain where they would find interesting and exotic species. They organized a trip to Brazil, which in 1848 was extraordinarily enterprising. They were basically making ends meet by selling their specimens as professional collectors, which is about as low as you could get on the naturalist’s pecking order. This is very different from Darwin’s gig, where he sails around the world as the captain’s paying guest on a Royal Navy ship.

Wallace and Bates split up fairly early on when they were in the Amazon. Bates went up the Amazon proper and Wallace specialized on the Rio Negro, spending an extraordinary four years there: He nearly died of yellow fever; his brother came out to help and did die of yellow fever; uncontacted tribes; the works. And all this was really with a view to becoming a member of the scientific establishment. He was going to come back, four years later, with this great collection, all these new species, all these observations, and he was going to be a scientist. But his boat, with all his specimens, including 20-odd living specimens, caught fire in the middle of the Atlantic, and literally everything was lost. He took only one small case of drawings with him. He spends ten days in an open boat, and then the boat that rescued him nearly went down as well!

What a string of hard luck! It’s amazing he didn’t give up.

Having survived that, he spends 18 months in the UK, puts out a book on his Amazon travels, which was one of the worst-selling books in history. Darwin himself was rather hard on it, saying there was a certain want of facts. Eighteen months later, Wallace was on his way to Southeast Asia to do it all over again. This time it was eight years largely in modern-day Indonesia. And again an extraordinary scientific journey: He was completely reliant on local people for their help, traveling alone, learning local languages. It’s the same gig as his Amazon trip, selling his specimens to make ends meet.

Then comes the second great out-of-the-blue event—Wallace and Bates going to the Amazon is the first —when in 1855 he publishes his first theoretical paper. Previously, he’s published a number of natural history notes—classic collector sort of things, this is where you find these monkeys, these birds. Then, when he’s in Sarawak, in northern Borneo, he produces this remarkable work of synthesis. It’s a full-born evolutionary idea in so far as the standard theory of evolution has two strands. One is descent with modification, that we’re all related to everyone else. Two is the mechanism that entrains that descent with modification, namely natural selection. The 1855 paper, “On the Law Which Has Regulated the Introduction of New Species,” is essentially a statement of the first half of the theory of evolution. The observation was that you found closely related, or closely allied species (as he would have called them) in the same geographic area. You find kangaroo species in Australia; you don’t find them elsewhere. That implies a genealogical process of some kind—that kangaroo species were giving rise to new kangaroo species.

Wallace expects his paper to create a big splash, but it doesn’t. Demoralized, he writes to Darwin. Darwin was encouraging in a slightly cagey kind of way, but he does go out of the way to do to reassure Wallace that he, too, is interested in the big picture, what you might call theory as opposed to details of taxonomy. And it was of course because of this that Wallace knew Darwin had a serious interest in these questions. It is interesting to read the correspondence because you see that Darwin is being gentlemanly but also slightly territorial.

Geologist Charles Lyell, Darwin’s mentor and friend, was much more struck by Wallace’s paper than Darwin was. He warned Darwin that he had been sitting on his ideas for getting on to 20 years now and here’s this Mr. Nobody coming up on the outside pretty fast. Darwin didn’t take it that seriously, but Lyell urged Darwin to get on with it or he would find himself scooped.

So how does Wallace stumble upon the idea of natural selection?

Ah, the moment of mechanism! The famous story of Wallace happens in February 1858 while he was on the island Halmahera (then Gilolo) in the Moluccas. He was suffering from malaria. While in a feverish state, he was thinking about Malthus, who was also a big player in Darwin’s thinking, and specifically about humans. Wallace was very interested in how there’s a replacement of people through Southeast Asia from an Asiatic type to a Melanesian type, so he was thinking essentially about racial conflict. And Malthus was all about the viability of human populations in the face of geometric growth with limited resources at their disposal.

In this malarial fit, he put two and two together, and natural selection was born. And as soon as he could he penned the manuscript. And the great freakish thing about it was that he sent it to Darwin. Every other paper he had sent directly to an editor or journal. And if he had done that, Darwin would have woken up, three months later, scooped, so this is the luckiest thing that ever happened to Charles Darwin. And I’m sure the reason Wallace did this stemmed from the disappointment of the reception of his previous big idea, so he figured he have it placed. He’d send it to Darwin with a view to him relaying it to Lyell. Essentially he’s pulling all his connections to big time science. He sends if off in February 1858.

Wallace has become this historical footnote. Do you think this is the role he deserves?

He definitely deserves more prominence than he receives. I think it’s kind of interesting that the world has become so Darwin-centric. And I do think there are several reasons for that. We can legitimately regard Darwin as first. Unfortunately, in science, being second doesn’t get you anywhere. Two, Wallace and Darwin responded to the publication of the Origin in two very different ways. Darwin saw it as the foundation of all his future work. He lived for another 23 years and published a good number of books in that time, all of them building upon the Origin. The Origin was the foundation, and he was buttressing it, bringing facts in, extending the theory to include sexual selection.

What did Wallace do?

When Wallace came back from Indonesia, he was famous and actually rich from his collecting trip. He didn’t have any disasters like the one with the Amazon trip. His nearest disaster was with a pair of living birds of paradise, which were his real ticket to success in London. He had this problem when he got to the Mediterranean—he was on a P & O steamer, which was too well maintained—because he had been feeding the birds of paradise live insects from the kitchens, cockroaches, I think, and there was this awful moment, steaming across the Mediterranean, when he had nothing to feed his birds. So what he manages happily to do when the ship stops in Malta is find a thoroughly cockroach-infested bakery, where he can stock up on insects.

So he’s back in London. He’s now achieved what he wanted to achieve. He’s part of the scientific elite. He’s up there. He’s Darwin’s right-hand man so to speak, and he’s wealthy. And then very rapidly he wasn’t. He was a very catastrophic investor. He trusted people he shouldn’t have.

So we have this contrast of Darwin slowly and steadily building on his argument and Wallace…

Goes bananas. He’s still doing great science, but he publishes—his bibliography runs to some 800 articles now—on everything. He becomes heavily politicized. He becomes a socialist. He was the president of Land Nationalization Society, which believed that private land ownership was the great root of all modern evil and that the state should own all land and rent it at equitable rates across the board. He became a spiritualist. Wallace remained convinced to his dying day that spirits, including those of dead humans, influence one’s fate to some extent and that you can communicate with them.

Even though Wallace believed in spiritualism, could he be considered in any way a creationist or an early intelligent designer?

Again that becomes a matter of definition. He was an absolute hardcore natural selectionist. In fact, as he writes in his autobiography, in many ways he was more Darwinian than Darwin in this regard. The big thing that he did drop the ball on, and he first announced this about ten years after the publication of the Origin, was that he decided that natural selection could not account for the evolution of humans. It deeply disturbed Darwin to lose his co-discoverer on this critical point on the theory of evolution. He wrote Wallace, “I hope you have not murdered too completely your own and my child.” In this regard you could legitimately call Wallace a creationist. He was a non-materialist in terms of one aspect of the evolutionary process.

How did Darwin and Wallace differ on their understanding of the evolution of humans?

Wallace deemed there to be some kind of divine intervention. He was not a theist in the sense of believing in God or even a polytheist. His vision of the divine was of this nebulous, multifarious spirit world. Wallace believed that humans are endowed with spirit and that is what lingers on and you can communicate with post-mortem.

And Darwin was basically by the book: natural selection has created humans. For him, mankind evolved in the same way as mice and fruitflies did. He had no need of divine intervention in the evolution of humans.

Did Wallace’s work advance the idea of speciation more than Darwin’s?

Yes, I think so. You can’t really discuss the mechanism of speciation whereby one species splits into two until you have a very concrete notion of what species are. So you need a good definition. Darwin’s definition of species is essentially that there are extreme varieties. Think of varieties of a rose, you can have a pink rose and a yellow rose and if you keep going along that line of variability eventually you’ll have a different species. And I should add that it was sort of rhetorically necessary for Darwin to do that given his argument, because people were comfortable with the notion of two different varieties of rose from their Victorian gardens. So all he’s saying is, look, there’s nothing mysterious about this; there are slightly more different varieties and we call them species, which is true, but you need something more illuminating, you need some notion of where that cutoff occurs. We now recognize typically that it’s where the members of one population cease to be capable of interbreeding with members of the other population.

When does this definition of species originate?

There’s a big literature on this, but the most exquisite statement of this fact is made by Wallace in his butterfly paper from 1864-65, where he writes that species are these groups of individuals capable of interbreeding with others within the group but not with individuals from outside the group—they’re reproductively isolated from each other. Very few people know that Wallace came up with this definition of species. This idea—it’s called the biological species concept—is certainly one of the most important ideas in evolutionary biology in that speciation is really the engine of biodiversity. You’ve really got to come to terms with speciation if you want to understand the generation of biological diversity.

What was Wallace’s reaction to his secondary role in relation to Darwin?

Wallace hears from London that the co-publication has occurred and he’s thrilled. Remember he’s already 15 years into his attempt to elevate himself from being this obscure nobody. There’s been a lot of water under the bridge; he’s finally made it. And he writes this lovely letter to his mother in October that year [1858] in which he exalts in the fact that when he comes back he’ll have the acquaintance of learned men of science. Clearly, the notion doesn’t occur to him that in some sense Mr. Darwin has ripped him off. Not in all of his personal writings is there a single grumble.

The next phase of things is publication of The Origin of Species, which barely makes mention of Wallace. And again, Wallace is just blown away. He writes to his friends that there is no way that he could have done that. “Mr. Darwin has given the world new science…. The force of admiration can no further go.” And through the rest of his life he always deferred to Darwin. His major book on evolutionary biology, he titled Darwinism. Darwin was the senior guy. Wallace felt that he got to where he got on Darwin’s coattails.

Wallace seems to be having a slight resurgence with a host of recent books out on him…

I think there are two things going on. One is saturation: the Darwin seams have been worked and worked. The other thing relates to the history of science, in which it’s sort of uncool to think in terms of individual heroic labor and striving. Ideas are an emergent property of the socio-political environment in which the individuals find themselves, which is manifestly true in this case. This is the most important idea in history, bar none—sought after since the Greeks. Suddenly, you have two people stumbling upon it independently, so in other words it’s not independent. There is something particular about this time and place: Britain at the height of Empire; opportunity for global travel and sudden encounter with the diversity of forms—the forms are pouring into the museums; colonial and industrial Britain, which is essentially a social Darwinian concept; Malthus is looming large. There are all sorts of good reasons.

So we’ve had Darwin, Darwin, Darwin. Then you start thinking that given the fact that we have two people coming up with natural selection at the same time and we don’t think it’s just down to genius individuals anymore, where else should we be looking? And Wallace is obviously the next place.