Although the developmental arguments in the Quartz & Sejnowski target article may have intrinsic merit, they do not warrant the authors' conclusion that innate modular architectures are absent or minimal, and that neocortical evolution is simply a progression toward more flexible representational structures. Modular architectures can develop and evolve in tandem with sub-cortical specialisation. I present comparative evidence for the co-evolution of specific thalamic and cortical visual pathways.

Evolutionary theory and methods are central to understanding the design of organisms, including their brains. This book does much to demonstrate the value of evolutionary neuroscience. Further work is needed to clarify the ways that neural systems evolved in general (specifically, the interaction between mosaic and coordinated evolution of brain components), and phylogenetic methods should be given a more prominent role in the analysis of comparative data.

The opposition set up between co-ordinated and mosaic brain evolution distracts from the fact that the two go hand-in-hand. Here and elsewhere (Barton & Harvey 2000), I show that the patterns of co- ordinated evolutionary change among brain structures fit a mosaic evolution model. The concept of overarching developmental constraints is unnecessary and is not supported by the data.

The hypothesis that play behavior is more prevalent in larger-brained animals has recently been challenged. It may be, for example, that only certain brain structures are related to play. Here, we analyze social play behavior with regards to the cerebellum: a structure strongly implicated in motor-development, and possibly also in cognitive skills. We present an evolutionary analysis of social play and the cerebellum, using a phylogenetic comparative method. Social play frequency and relative cerebellum size are positively correlated. Hence, there appears (...) to be a link between the evolutionary elaboration of social play and the cerebellum. (shrink)

Sexual behaviour and mate choice are key intervening variables between attachment and life histories. We propose a set of predictions relating attachment, reproductive strategies, and mate choice criteria.