Language Evolution and Computation Bibliography

Humans acquire far more of their behaviour from conspecifics via culture than any other species. Our culture is larger because it accumulates, where other species' seem to stay approximately the same size (Tomasello, 1999). This chapter attempts to clarify the problem of cultural accumulation by distinguishing between the size of a culture that can be transmitted from one generation, and the extent of culture transmitted. A culture's size is determined largely by ecological constraints, and certainly homonins (and some other species) show adaptations to facilitate this. But the exponential accumulation hypothesised by (Tomasello, 1999) I claim cannot be accounted for this way, but rather is a consequence of increasing information value in semantic components. This process can be achieved through memetics --- semantics will be selected for which transmits the most information. Thus cultural evolution achieves compression of information, generating increased extent in culture even when maintaining a fixed size. I support my argument with evidence from simulations explaining the size of culture (ae and Bryson, 2007), and simulations demonstrating selection for increased extent Kirby (1999).

Social learning is a source of behaviour for many species, but few use it as extensively as they seemingly could. In this article, I attempt to clarify our understanding of why this might be. I discuss the potential computational properties of social learning, then examine the phenomenon in nature through creating a taxonomy of the representations that might underly it. This is achieved by first producing a simplified taxonomy of the established forms of social learning, then describing the primitive capacities necessary to support them, and finally considering which of these capacities we actually have evidence for. I then discuss theoretical limits on cultural evolution, which include having sufficient information transmitted to support robust representations capable of supporting variation for evolution, and the need for limiting the extent of social conformity to avoid ecological fragility. Finally, I show how these arguments can inform several key scientific questions, including the uniqueness of human culture, the long lifespans of cultural species, and the propensity of animals to seemingly have knowledge about a phenomenon well before they will act upon it.

The term embodiment identifies a theory that meaning and semantics cannot be captured by abstract, logical systems, but are dependent on an agent's experience derived from being situated in an environment. This theory has recently received a great deal of support in the cognitive science literature and is having significant impact in artificial intelligence. Memetics refers to the theory that knowledge and ideas can evolve more or less independently of their human-agent substrates. While humans provide the medium for this evolution, memetics holds that ideas can be developed without human comprehension or deliberate interference. Both theories have profound implications for the study of language -- its potential use by machines, its acquisition by children and of particular relevance to this special issue, its evolution. This article links the theory of memetics to the established literature on semantic space, then examines the extent to which these memetic mechanisms might account for language independently of embodiment. It then seeks to explain the evolution of language through uniquely human cognitive capacities which facilitate memetic evolution.

What purposes, other than facilitating the sharing of information, can language have served? First, it may not have evolved to serve any purpose at all. It is possible that language is just a side effect of the large human brain—a spandrel or exaptation—that only became useful ...