Language Evolution and Computation Bibliography

Many of the issues that confront designers of interactive computer systems also appear in natural language evolution. Natural languages and human-computer interfaces share as their primary mission the support of extended ''dialogues'' between responsive entities. Because in each case one participant is a human being, some of the pressures operating on natural languages, causing them to evolve in order to better support such dialogue, also operate on human-computer ''languages'' or interfaces. This does not necessarily push interfaces in the direction of natural language - since one entity in this dialogue is not a human, this is not to be expected. Nonetheless, by discerning where the pressures that guide natural language evolution also appear in human-computer interaction, we can contribute to the design of computer systems and obtain a new perspective on natural languages.

The intricate phenomena of biology on one hand, and language and culture on the other, have inspired many writers to draw analogies between these two evolutionary systems. These analogies can be divided into four principal types: species/language, organism/concept, genes/culture, and cell/person. I argue that the last analogy--between cells and persons--is the most profound in several respects, and, more importantly, can be used to generate a number of empirical predictions. In the first half of the paper, the four analogies are each evaluated after briefly describing criteria for a good predictive analogy. In the second half of the paper, the cell/person analogy and predictions deriving from it are explored in detail.

It is necessary to relate functional explanations to the whole issue of innateness, which has been so crucial in the development of formal explanations in linguistics. For instance, it is not excluded that functional principles might be innate.... This raises the interesting question of how innate ideas turn out to be `correct' (more accurately, functionally valuable) ideas, as the result of selectional pressure in evolution. (Comrie, 1983, p. 99.)

Evidence suggests that there is a critical, or at least a sensitive, period for language acquisition, which ends around puberty. The existence of this period is explained by an evolutionary model which assumes that (a) linguistic ability is in principle (if not in practice) measurable, and (b) the amount of language controlled by an individual conferred selective advantage on it. In this model, the language faculty is seen as adaptive, favoured by natural selection, while the critical period for language acquisition itself is not an adaptation, but arises from the interplay of genetic factors influencing life-history characters in relation to language acquisition. The evolutionary model is implemented on a computer and simulations of populations evolving under various plausible, if idealized, conditions result in clear critical period effects, which end around puberty.

In this book, Lightfoot explores in some detail issues that he raised in an important recent article {Lightfoot, 1989). The main claim of that article and of this book is that the triggering evidence required to set the parameters of Universal Grammar (UG) should be degree-0, ...