Today is the 185th anniversary of Alfred Russel Wallace. He’s best known, of course, as the young(ish) scientist who, while recovering from malaria somewhere in Indonesia, independently came up with the same ideas about evolution that Darwin had been working on for three decades, wrote them up, mailed them to Darwin, and catalyzed the old boy into finally getting the damn book written. In fact, that part of his career is so well known that it’s hard to find any mention of Wallace that doesn’t also bring up Darwin. Despite his enormous talents as a naturalist, he’s almost always cast as Darwin’s sidekick. Today is his birthday, though, so it doesn’t really seem nice to leave him in the Boy Wonder role. Instead, let’s take a look at an outstanding paper that he published in 1855.
First, though, let’s set the scene properly. By 1855, Darwin had spent nearly two decades actively investigating the evolution of species. For various reasons, he had not yet published his hypothesis, but he had confided it to a friend and colleague of his - botanist Joseph Hooker - in 1844. The question of how species were formed had been the topic of intense debate for years, and a number of scientists were approaching the topic from different angles. And Alfred Russel Wallace had been in the Malay Archipelago for about a year.
Although Wallace had spent some time around the fringes of the highly social and very upper class world of British naturalists by then, he was hardly an intimate member of their group. His modest background deprived him of the luxury of being able to pursue science as a hobby - unlike Lyell or Darwin, he had to work for a living. This turned out to be quite an advantage for him in some ways, though. He supported himself as a naturalist by collecting samples for wealthy people who kept natural history collections as a hobby. This meant that where some of his scientific peers might collect one or two samples of a species, Wallace collected - and examined - many more than that. It also meant that he had an enormous incentive to know what species lived where - it was his livelihood. Over the years that he’d spent time in the Amazon and the shorter time he’d spent in Indonesia, Wallace had looked at and thought about an enormous number of species of plants and animals, and had felt secure enough in his knowledge to not only report some of the facts that he had learned, but to also draw some more general conclusions from those facts.