This book is about the plants and animals of urban areas, not the urban fringe, not encapsulated countryside but those parts of towns where man's impact is greatest. The powerful anthropogenic influences that operate in cities have, until recently, rendered them unattractive to ecologists who find the high proportion of exotics and mixtures of planted and spontaneous vegetation bewildering. They are also unused to considering fashion, taste, mowing machines and the behaviour of dog owners as habitat factors. I have always maintained, however, and I hope this book demonstrates, that there are as many interrelationships to be uncovered in a flower bed as in a field, in a cemetery as on a sand dune; and due to the well documented history of urban sites, together with the strong effects of management, they are frequently easier to interpret than those operating in more natural areas. The potential of these communities as rewarding areas for study is revealed in the literature on the pests of stored products, urban foxes and birds. The journals oflocal natural history societies have also provided a rich source of material as amateurs have never been averse to following the fortunes of their favourite groups into the heart of our cities. It is predictable that among the few professionals to specialize in this discipline have been those enclosed in West Berlin, who must be regarded as among the leading exponents of urban ecology.

This volume – for pharmacologists, systems biologists, philosophers and historians of medicine – points to investigate new avenues in pharmacology research, by providing a full assessment of the premises underlying a radical shift in the pharmacology paradigm. The pharmaceutical industry is currently facing unparalleled challenges in developing innovative drugs. While drug-developing scientists in the 1990s mostly welcomed the transformation into a target-based approach, two decades of experience shows that this model is failing to boost both drug discovery and efficiency. Selected targets were often not druggable and with poor disease linkage, leading to either high toxicity or poor efficacy. Therefore, a profound rethinking of the current paradigm is needed. Advances in systems biology are revealing a phenotypic robustness and a network structure that strongly suggest that exquisitely selective compounds, compared with multitarget drugs, may exhibit lower than desired clinical efficacy. This appreciation of the role of polypharmacology has significant implications for tackling the two major sources of attrition in drug development, efficacy and toxicity. Integrating network biology and polypharmacology holds the promise of expanding the current opportunity space for druggable targets.