Invasion biology’s forgotten forerunners

Invasion biologists and allied popular authors traditionally and reverently identify Charles Elton’s 1958 book, The Ecology of Invasions by Animals and Plants, as their specialty’s seminal and founding document. But in the past few years, ecologists including Petr Pyšek and Marc William Cadotte have cast brief backward glances at earlier literature; at the 2006 ESA Annual Meeting, James T. Carlton described publications from as early as 1885. Drawing from my 2006 dissertation, Ending with Elton: Preludes to Invasion Biology, I briefly sketch the interests, studies, and attitudes, of over twenty natural historians, botanists, zoologists, ecologists, (and others) who actively puzzled over the human redistribution of biota. These men (and one woman) worked during the 18th, 19th and early 20th centuries, in Europe, Asia, Africa, the Americas, Australia and various island groups. Some of them are broadly familiar (e.g., Darwin, Wallace and Leopold); others are remembered within narrow subspecialties (e.g., Kalm, deCandolle, and Thellung); many are rarely recalled at all (e.g., Hayward, Binney, and Pickering). Some of their motivations and methods seem familiar, while others are “alien” to currently prevailing sensibilities. Most regarded the study as a sideline; many reinvented it from scratch. Elton, who first published regarding species introductions in 1925, was unaware of most of his co-specialists, including those recently or still active. As a group they left little clear disciplinary legacy, except for problematic attempts to classify varieties of nativeness, which I call anekeitaxonomy (from the Greek ανηκει, “belonging”).