16. Some ecological properties of language development
The formation of distinct languages and distinct species, and the proof that these have developed through a gradual process, are curiously parallel, as argued by one of the founding fathers of the comparative method, Schleicher (1861). Although the notion of gradualness has been relaxed more recently in evolutionary biology as well as in historical linguistics, the genealogical line that can be established and the persistence of systems with modification both in the historical development of languages and in biological speciation, as manifested in the continuation as well as the individuation, are notoriously similar. Never-theless, whereas the evolution of species and the evolution of language are identical in form, their fundamental causes are different. There is no convincing evidence, for example, that human language has developed from less advanced to more complex stages in any sense. The few unfortunate attempts that have been made to try and show that language indeed moved from primitive towards more advanced stages, have failed. As shown by Joseph (2004), evolutionary theories of languages go back a few thousand years. During the 19th century and the beginning of the 20th century, authors tried to find explanations for language change in climate, topography, or attitude. Thus, Whitney (1904: 84–85) assumed that least effort, laziness, or carelessness might be the cause for language change. The research of William Labov and other sociolinguists has shown that neither uncultivated nor careless speakers are the “corrupters” of language, and that instead centrally located individuals play a quintessential role in the transition of innovations in, for example, American metropoles. At the same time, there are a number of interesting parallels between the historical development of biological systems and languages, as argued below. These involve the speed with which changes may occur, the degree of genetic and typological diversity in some areas as opposed to others, and so-called self-organising principles.