Language Evolution and Computation Bibliography

This article focuses on one aspect of a comprehensive theory of human cognitive evolution, and that is mimesis. Mimesis is an embodied, analogue, and primordial mode of representation, in the sense that it is a preadaptation for language and also a self-sufficient cognitive adaptation in its own right, which accounts for some of the major features of human cultural and cognitive life. A mimetic act is a performance that reflects the perceived event structure of the world, and is the purest form of embodied representation. It has three behavioral manifestations that include rehearsal of skill, in which the actor imagines and reproduces previous performances with a view to improving them. Other include re-enactive mime, in which patterns of action, usually of others, are reproduced in the context of play or fantasy, and lastly, non-linguistic gesture, where an action communicates an intention through resemblance. The contents of mimetic acts are observable by others, which makes them a potential basis for a culturally accepted mimetic vernacular, enabling members of a group to share knowledge, feelings, customs, skills, and goals, and to create group displays of emotions and intentions that are conventional and deliberate. These types of shared representations seem quite limited, when compared to language, but constitute a powerful means of creating culture and sharing custom, feeling, and intent.

Because language doesn't fossilize, it is difficult to unambiguously time the evolutionary events leading to language in the human lineage using traditional paleontological data. Furthermore, techniques from historical linguistics are generally seen to have an insufficient time depth to tell us anything about the nature of pre- modern-human language. Thus hypotheses about early stages of language evolution have often been seen as untestable ''fairy tales''. However, the discovery of human-unique alleles, associated with different aspects of language, offers a way out of this impasse. If an allele has been subjected to powerful selection, reaching or nearing fixation, statistical techniques allow us to approximately date the timing of the selective sweep. This technique has been employed to date the selective sweep associated with FOXP2, our current best example of a gene associated with spoken language. Although the dates themselves are subject to considerable error, a series of different dates, for different language-associated genes, provides a powerful means of testing evolutionary models of language if they are explicit and span the complete time period between our separation from chimpanzees to the present. We illustrate the potential of this approach by deriving explicit timing predictions from four contrasting models of ''protolanguage.'' For example, models of musical protolanguage suggest that vocal control came early, while gestural protolanguage sees speech as a late addition. Donald's mimetic protolanguage argues that these should appear at the same time, and further suggests that this was associated with Homo erectus. Although there are too few language-associated genes currently known to resolve the issue now, recent progress in the genetic basis for dyslexia and autism offers considerable hope that a suite of such genes will soon be available, and we offer this theoretical framework both in anticipation of this time, and to spur those developing hypotheses of language evolution to make them explicit enough to be integrated within such a hypothesis-testing framework.