Several people have emailed/tweeted at me about the new paper in Science, Phonemic Diversity Supports a Serial Founder Effect Model of Language Expansion from Africa:
Human genetic and phenotypic diversity declines with distance from Africa, as predicted by a serial founder effect in which successive population bottlenecks during range expansion progressively reduce diversity, underpinning support for an African origin of modern humans. Recent work suggests that a similar founder effect may operate on human culture and language. Here I show that the number of phonemes used in a global sample of 504 languages is also clinal and fits a serial founder–effect model of expansion from an inferred origin in Africa. This result, which is not explained by more recent demographic history, local language diversity, or statistical non-independence within language families, points to parallel mechanisms shaping genetic and linguistic diversity and supports an African origin of modern human languages.
Though there are major differences between biological evolution, constrained by relatively regular forms of inheritance, and cultural evolution, which is much more potentially protean, I think that there is great potential for unity of model and process. That is why I read A Replicated Typo (and presumably why several of the contributors to that weblog read the content here). But I generally have zero ability to evaluate the linguistic plausibility of these sorts of hypotheses about the origin and development of languages. Generally attempts to translate biological models into linguistics seem to be met with skepticism, but Nick Wade in The New York Times has some quotes from linguists who do not seem overly hostile toward the new model. This in particular was kind of funny in my opinion:
“We’re uneasy about mathematical modeling that we don’t understand juxtaposed to philological modeling that we do understand,” Brian D. Joseph, a linguist at Ohio State University, said about the Indo-European tree. But he thinks that linguists may be more willing to accept Dr. Atkinson’s new article because it does not conflict with any established area of linguistic scholarship.“I think we ought to take this seriously, although there are some who will dismiss it out of hand,” Dr. Joseph said.
Sociology of science in action! In any case, I'm waiting to see if anyone at A Replicated Typo will humor me and perhaps touch upon the plausibility of this model. It isn't as if everything published in Science is really quite as firm as outsiders might assume. This is a huge finding if valid. But extraordinary claims need to be met with caution.