Ultraconserved words point to deep language ancestry across Eurasia
- aSchool of Biological Sciences, University of Reading, Reading, Berkshire RG6 6AS, United Kingdom;
- bSanta Fe Institute, Santa Fe, NM 87501;
- cSchool of Psychology, University of Auckland, Auckland 1142, New Zealand
- dLinguistics Programme, University of Waikato, Hamilton 3240, New Zealand
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Edited* by Colin Renfrew, University of Cambridge, Cambridge, United Kingdom, and approved April 15, 2013 (received for review October 31, 2012)
Abstract
The search for ever deeper relationships among the World’s languages is bedeviled by the fact that most words evolve too rapidly to preserve evidence of their ancestry beyond 5,000 to 9,000 y. On the other hand, quantitative modeling indicates that some “ultraconserved” words exist that might be used to find evidence for deep linguistic relationships beyond that time barrier. Here we use a statistical model, which takes into account the frequency with which words are used in common everyday speech, to predict the existence of a set of such highly conserved words among seven language families of Eurasia postulated to form a linguistic superfamily that evolved from a common ancestor around 15,000 y ago. We derive a dated phylogenetic tree of this proposed superfamily with a time-depth of ∼14,450 y, implying that some frequently used words have been retained in related forms since the end of the last ice age. Words used more than once per 1,000 in everyday speech were 7- to 10-times more likely to show deep ancestry on this tree. Our results suggest a remarkable fidelity in the transmission of some words and give theoretical justification to the search for features of language that might be preserved across wide spans of time and geography.
Footnotes
- ↵1To whom correspondence should be addressed. E-mail: m.pagel{at}reading.ac.uk.
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Author contributions: M.P., Q.D.A., A.S.C., and A.M. performed research; M.P. and A.M. contributed new reagents/analytic tools; M.P., Q.D.A., A.S.C., and A.M. analyzed data; and M.P., Q.D.A., and A.S.C. wrote the paper.
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The authors declare no conflict of interest.
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↵*This Direct Submission article had a prearranged editor.
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This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10.1073/pnas.1218726110/-/DCSupplemental.
Freely available online through the PNAS open access option.
