Geoff Chambers

The new millennium has opened with a perfectly splendid decade of scholarship relating to the ‘Species Problem’. So, at least we now have a clear idea of what this is, but still no clear solution that will suit both biologists and philosophers. Richards has recently attempted to capture this story and to fill the void with two projects in one book. The first project is a descriptive and analytical history of the problem, which provides links to other recent works and thereby allows one to fully reconstruct the literature. The second is prescriptive and presents Richards’s solution via a ‘division of labour in a conceptual framework’ followed by recapitulation and conclusions. It is my assessment as presented here that the first project will appeal more to biologists and the second one to philosophers. There is much of value in Richards approach including an excellent evaluation of the essentialism story in the descriptive project and clear exposition of several key issues such as the ‘species-as-individuals’ versus ‘species-as-categories’ debate which are covered in the second project. Interesting and informative as these arguments undoubtedly are, something still seems to be missing here. In this essay I suggest that this perception arises from Richards’ failure to embrace ideas about the importance of relativity and contingency in species definitions and further that his new conceptual framework lacks one hierarchical level to link overarching lineage concepts of species as evolutionary units with practical definitions for their recognition. In my view, the missing link is reproductive isolation and I conclude my review by presenting a prescriptive project for biologists to balance the one that Richards has delivered to philosophers.

In recent years a new conceptual tool called Complexity Theory has come to the attention of scientists and philosophers. This approach is concerned with the emergent properties of interacting systems. It has found wide applicability from cosmology to Social Structure Analysis. However, practitioners are still struggling to find the best way to define complexity and then to measure it. A new book Complexity and the arrow of time by Lineweaver et al. contains contributions from scholars who provide critical reviews of Complexity Theory and its wider applications. This is a huge task and this essay examines how well the authors have succeeded in satisfying the claim made by the book’s three editors to have clarified the leading questions. I also explore the application of Complexity Theory to Biology as a means to explain the popular view that biological complexity has increased over time. In this regard, I conclude by recommending an Information Theory approach which urges that physical complexity arises from accumulation of genetic coding sequences.