EDGE: What does one do for eight years in an archipelago?

SHERMER: You collect data. It's a brutal life. It's hot, it's humid, it's teeming with insects, the transportation by steamship is slow. You spend a lot of time waiting, writing lots of letters, but also sorting and collecting specimens. Now Darwin had money but Wallace never did. He actually had an agent in London, a guy named Stephens, to whom he would ship his collections. Stephens sold them to museums and private collectors, and mailed Wallace the money. It's a great case of a self-made man — he's going from island to island, waiting for his shipment to arrive and the money to come back so he can keep going. Without that, he would never have made it. So he's completely self-made. It's an admirable story.

EDGE: Was he alone?

SHERMER: In the Amazon he was with Bates of the famous Batesean mimicry, a prime example of which is in moths that mimic each other's protective coloration. In the Malay archipelago he had a couple of young assistants, but mostly he was by himself. It's hard for us to imagine that. It would be lonely and boring, but it seemed to suit his temperament.

EDGE: We can glibly say eight years, but try to think about that...Was there any social life or love interests?

SHERMER: There's not a shred of evidence in anything he ever wrote about women or his love life until he got home. So I don't know what he did.

EDGE: Was there a human population?

SHERMER: There were some indigenous people that he studied. Before anthropology really became solidified as a science, Wallace was an anthropologist, writing ethnographies of the local people. There's whole sections in his books on birds and travelogues and about the people. Many of the people he encountered had hardly ever seen a white man before, if ever, and he was tall, over six feet, and very gangly, so you can imagine this sort of tall, gangly, white bearded Englishman amongst these short, dark natives. He writes about this, how he'd come around a corner, and they'd scream and run. This was in Borneo, Java, Papua New guinea, and so on.

Wallace is probably most famous for founding the science of biogeography. What Edward O. Wilson does is what Wallace created. The idea of studying island biogeography is one of the most important things you can use to understand evolutionary biology and evolutionary trends, because islands are little self contained communities separated by water. Water becomes a geographic isolating mechanism. Varieties that are separated long enough can't reconnect to their original gene pools. They become different enough through mutation and genetic drift that when they are reintroduced, they do not interbreed for whatever reason, or if they do, they don't have viable offspring. That constitutes a new species. Really it's Wallace who founded that field, not Darwin. Darwin gets more credit than Wallace for the overall program, but it's Wallace's biogeography that really lays the groundwork for understanding evolution.

EDGE: How does this fit in with the work of Jared Diamond?

SHERMER: Jared knows all about this stuff because he has retraced, just by chance, much of Wallace's route. Jared's new book with biologist Ernst Mayr about the birds of Papua New Guinea is exactly island biogeography. They're doing what Wallace did for eight years. By doing that you understand the evolutionary process, you understand the impact of changing an environment for a species. The reason why what Jared and Ernst are doing now is so important is because it's a form of environmental monitoring. We can look back at what certain species were like a century ago and half a century ago and today, and look at how the environment has been altered by humans and how that's mucking up the future of life.

EDGE: So there's a direct line from Wallace?

SHERMER: It's a perfect segue from Wallace, because Mayr bridges us from Wallace to today. Wallace died in 1911, and Ernst was born in 1904. So he was alive when Wallace was alive, which is incredible. Ernst, of course, is still going strong, and really, in a sense, he took the work of Wallace and Darwin and synthesized it. Mayr is one of the grand synthesizers of the 30s and 40s and his definition of a species is actually derived from Wallace's notion of biogeography. We've all had to memorize it: a species is a group of actually or potentially interbreeding natural populations, reproductively isolated from other such populations.

That's what a species is, which is not a linguistic artifact of human classification; it's real. The natives of Papua New Guinea identify the same organisms in the same way that Ernst and Jared do, almost without exception. They don't call them species, but whatever they do call them, they consider them to be different groups. The test is whether or not they interbreed. If they don't, they're separate species.

Overall, writing the biography of Wallace has proved to be one of the most interesting projects on which I have ever worked. I have learned so much about life — human and otherwise — and most importantly, about how science works.