Human language is unique among the communication systems of the natural world. The vocabulary of human language is unique in being both culturally-transmitted and symbolic. In this paper I present an investigation into the factors involved in the evolution of such vocabulary systems. I investigate both the cultural evolution of vocabulary systems and the biological evolution of learning rules for vocabulary acquisition.

The newest synthesis of evolutionary thought is emerging, and promises to return evolutionary biology to Darwin’s panoramic view of life. The key element is a long-standing dualism in evolutionary theory. This dualism has a long history within evolutionary biology, being manifested under guises such as: (1) the nature of the organism and the nature of the conditions, (2) internal and external, or intrinsic and extrinsic, factors, (3) production and exchanges, (4) boundary and initial conditions, (5) metabolism and replication, (6) energy and information, and (7) costs and benefits, and conflict and resolution. A partially retrospective review suggests that there is now a conceptual coherent framework for resolving the dualism, not by eliminating one component of the dualism but by integrating both.

James Mark Baldwin is remembered today almost exclusively for his paper ‘A New Factor in Evolution ’ (Baldwin, 1896a). The new factor, which he called ‘organic selection ’ and which later became known as the Baldwin effect, was a process that could cause ‘accomodations ’- the acquired adaptive responses of individual organisms- to

We present an individual-based, spatial implementation of an existing two-locus population genetic model of niche construction. Our analysis reveals that, across a broad range of conditions, niche-construction traits can drive themselves to fixation by simultaneously generating selection that favours ‘recipient ’ trait alleles and linkage disequilibrium between niche-construction and recipient trait alleles. The effect of spatiality is key, since it is the local, resource-mediated interaction between recipient and niche-constructing loci which gives rise to gene linkage. Spatial clustering effects point to a possible mechanism by which an initially rare recipient trait whose selection depends on niche construction could establish in an otherwise hostile environment. The same mechanism could also lead to the spread of an established niche-constructing colony. Similar phenomena are observed in the spatial modelling of two species ‘engineering webs’. Here, the activities of two niche-constructing species can combine to drive a particular recipient trait to fixation, or in certain circumstances, maintain the presence of polymorphisms through the preservation of otherwise deleterious alleles. This may have some relevance to ecosystem stability and the maintenance of genetic variation, where the frequencies of key resources are affected by the niche-constructing activities of more than one species. Our model suggests that the stability of multi-species webs in natural populations may increase as the complexity of species–environment interactions increases.

Introduction Fire is a disturbance factor in ecosystems worldwide and affects the reproduction of many plant species. For some species, it is just one of several disturbances that trigger seed germination and subsequent seedling recruitment, whereas in other `fire-dependent ' species, fire may be required for seedling recruitment. Fire may trigger seed regeneration directly, through the opening of serotinous fruits or cones or by inducing the germination of dormant soil-stored seed banks. Fire may also indirectly initiate seedling recruitment by opening gaps in closed vegetation, thus providing conditions suitable for colonization. There is a multitude of mechanisms for capitalizing upon such disturbances and the particular mode is a function of fire regime, climate, growth form, phylogeny and biogeography. Postfire environments Fire causes a multitude of changes in the environment that enhance site quality for seedling recruitment and thus provide the selective impetus for fire-dep

lineages in evolution