Available online at www.sciencedirect.com Physics of Life Reviews 8 (2011) 367–368 www.elsevier.com/locate/plrev Comment An ecological account of language evolution! Way to go! Commentary on “Modeling the cultural evolution of language” by Luc Steels Salikoko S. Mufwene University of Chicago, Department of Linguistics, 1010 E. 59th Street, Chicago, IL 60637, USA Received 13 October 2011; accepted 14 October 2011 Available online 25 October 2011 Communicated by L. Perlovsky Luc Steels [1] has just demonstrated how useful modeling can be to investigations on language evolution, includ- ing both language change and the phylogenetic emergence of language. He shows that language must have evolved gradually, by successive co-options of hominines’ mental capacities and anatomical structures, at different stages of the human phylogeny, in response to ever-increasing communicative pressures arising from social interactions. Self- scaffolding appears to have played a central role: the same mind that helped hominines evolve conspecific cooperation and a more complex social organization than other primates also helped them produce a more complex culture, in- cluding a wider range of tools and, particularly, more complex communicative means for more explicit exchanges of information, viz., languages. (As explained below, they need not have emerged monogenetically.) Languages may be conceived of as hybrid technologies (like computers, consisting of hardware and software) produced by the gradual domestication of the hominine anatomy by the mind since Homo erectus. In the case of speech, this involved co-opting the lungs and the buccopharyngeal structure for the production of phonetic sounds, the hardware that left no choice but to manipulate the ensuing linear structure toward producing rich vocabularies and complex utterances. An important question has been how to account for the transition from vocalizations to phonetic communication. As hypothesized long ago by Jean-Jacques Rousseau [2], pressures for a larger vocabulary would have evolved vocalic differentiation followed by syllabic variegation [3], which enhanced perception and the potential for large numbers of symbols. Syntax as rule-governed compositionality would have started at the word level, with culture-specific principles regulating how sounds could combine to produce acceptable words. The technology also breaks the linear sequencing of sounds with pauses to mark boundaries first between words and, at a higher level, between larger chunks construed as constituents and sentences. Principles that are partly culture-specific and partly universal regulate how words can combine into longer and complex utterances: sentences and narratives. Pace Steels, constituent structure facilitates mental processing. Internal word structure (morphology, which forgoes pauses) would have emerged later to facilitate vocabulary growth. Module-specific “rules” and “constraints” would have emerged both to systematize the production of words and longer utterances. Mutual accommodations between interactants produced communal norms, minimizing commu- nication failure. Steels is correct in underscoring the significance of variation, a normal state of affairs in populations, DOI of original article: 10.1016/j.plrev.2011.10.014. E-mail address: s-mufwene@uchicago.edu. 1571-0645/$ – see front matter  2011 Elsevier B.V. All rights reserved. doi:10.1016/j.plrev.2011.10.011