Blute Blog

Blute's blog about evolutionary theory: biological, sociocultural and gene-culture.

New evidence for world-wide cultural transmission and evolution of languages from Africa

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Phil Regal kindly drew my attention to a post by Nicholas Wade and hence to Wade’s subject, a recent article by Quentin Atkinson in Science, “Phonemic diversity supports a serial founder effect model of language expansion from Africa” which is a real blockbuster.

Most historical linguists have long argued that historical relatedness among languages beyond families and a few super-families cannot be demonstrated with the kinds of linguistic evidence they prefer, and hence among other things they have been sceptical of the monogenesis theories and evidence of Merritt Ruhlen, Joseph Greenberg, Bernard Bichakjian and others. Atkinson has now exploded the former argument at least with a novel kind of linguistic evidence.

It has long been known that genetic and phenotypic diversity tends to be greatest in the homeland of a species and to decline towards its outermost ranges (e.g. in humans among Africans as opposed to elsewhere). That is because of serial founder effects. Increasingly distant local populations are founded by small, non-random samples of migrants from the less distant. Atkinson has now shown that the same thing obtains for phonemes of languages (the basic set of sounds including vowels, consonants and tones). In 504 languages around the world, Atkinson shows that a language has fewer phonemes the further one travels from Africa (actually specifically from central and southern Africa). Of course this effect of linguistic drift like that of genetic drift on diversity would decline if and when the more distant populations become large as well so Atkinson includes speaker population size in his models but the shadow of history remains impressively robust nevertheless.

The very first post I made to this blog in March of last year supported a common origin of human languages based not on linguistic, but on genetic evidence. I reasoned that if Homo sapiens sapiens share a single or perhaps two common historical origins in Africa 50,000 or so years ago as is currently thought (and nobody thinks language emerged later than that and many think much earlier), then the existence of a one or at most two “mother tongues” seems almost inescapable unless one wished to argue that one or more groups stopped talking for some generations and then began anew again which seems most unlikely. Atkinson does not argue specifically for a monogenesis theory of language. “This region (central and southern Africa) could represent either a single origin for modern languages or the main origin under a polygenesis scenario.” Nevertheless, his research provides strong evidence for the world-wide cultural transmission and evolution of human languages from Africa.

To evolutionists, his evidence is very powerful and the care with which the research was conducted is impressive including controls that biologists like to see such as those for the possibility of non-independence within language families. The quotes that Wade has obtained from traditional historical linguists on the article suggest that this may be the turning point for them to become more open on the subject. I will indulge in one minor complaint about how the ubiquitous developmental rather than an evolutionary analogy holds sway in the title of his comment -  “Languages Grew From a Seed in Africa, Study Says”. NO NO NO! Languages (plural) did not “grow from a seed”, they evolved from an ancestor!

Anatol Rapoport, the game theorist of “tit-for-tat” fame among evolutionists, co-authored an article in the first issue of Behavioral Science in 1956 arguing for a detailed analogy between biological and cultural evolution, specifically with respect to language. Many years later he was on my Ph.D. thesis committee comparing theories of change in biology, psychology and the social sciences. The last time I saw him before he died was at a social gathering; he was quite deaf by then and the background noise was considerable. He took a firm hold of my arm and was very intense in telling me that he wanted me to know that  phonemes are the (Mendelian) genes of languages. I know he would have loved Atkinson’s article.

Written by Marion Blute

April 18, 2011 at 10:10 pm

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