Language Evolution and Computation Bibliography

This thesis investigates the evolutionary plausibility of the Minimalist Program. Is such a theory of language reasonable given the assumption that the human linguistic capacity has been subject to the usual forces and processes of evolution? More generally, this thesis is a comment on the manner in which theories of language can and should be constrained. What are the constraints that must be taken into account when constructing a theory of language? These questions are addressed by applying evidence gathered in evolutionary biology to data from linguistics.

The development of generative syntactic theorising in the late 20th century has led to a much redesigned conception of the human language faculty. The driving question - `why is language the way it is' - has prompted assumptions of simplicity, perfection, optimality, and economy for language; a minimal system operating in an economic fashion to fit into the larger cognitive architecture in a perfect manner. Studies in evolutionary linguistics, on the other hand, have been keen to demonstrate that language is complex, redundant, and adaptive, Pinker & Bloom's (1990) seminal paper being perhaps the prime example of this. The question is whether these opposing views can be married in any way.

Interdisciplinary evidence is brought to bear on this problem, demonstrating that any reconciliation is impossible. Evolutionary biology shows that perfection, simplicity, and economy do not arise in typically evolving systems, yet the Minimalist Program attaches these characteristics to language. It shows that evolvable systems exhibit degeneracy, modularity, and robustness, yet the Minimalist Programmust rule these features out for language. It shows that evolution exhibits a trend towards complexity, yet the Minimalist Program excludes such a depiction of language.

By determining where language falls in each of these three cases, the choice between the opposing positions of gradual adaptive evolution and the Minimalist Program is resolved. Language is shown to be imperfect, uneconomic, and non-optimal, and hence a typical biological system. Language is shown to exhibit the key features of evolvability, and hence accords with the usual pressures and constraints of evolution. Language is shown to be both complex and adaptive, and hence amenable to a gradual adaptive evolutionary account.

In addition, the uniqueness of the pivotal property of language according to one minimalist evolutionary account - recursion - is examined, its place as just one of a collection of properties which make language special illustrating that language is significantly more complex and sophisticated than the Minimalist Program allows. Finally, significant flaws in the details of minimalist theories themselves - including extraneous operations, and unmotivated and stipulative features - are uncovered, further signalling that the perfection, simplicity, and economy that minimalism advocates is not a valid characterisation of language.

A recent proposal (Hauser, Chomsky \& Fitch, 2002) suggests that the crucial defining property of human language is recursion. In this paper, following a critical analysis of what is meant by the term, I examine three reasons why the recursion-only hypothesis cannot be correct: (i) recursion is neither unique to language in humans, nor unique to our species, (ii) human language consists of many properties which are unique to it, and independent of recursion, and (iii) recursion may not even be necessary to human communication. Consequently, if recursion is not the key defining property of human language, it should not be granted special status in an evolutionary account of the system.