The Evolution of Vertebrate Blood Clotting 

Russell F. Doolittle
University of California, San Diego



The evolution of blood clotting is a subject I have been thinking about for more than half a century. The general outlines of how the process evolved became apparent early, but the details, which are where the fascination lies, only gradually became available. Fortuitously, modern genome biology is now providing the wherewithal for interpreting events rationally. This book is my attempt to assemble the facts as presently understood.

Initially, I was in a dilemma about what level of readership to aim for. Should I be addressing biochemists and molecular biologists, individuals who are already familiar with the underlying science and general concepts? Or, could I broaden the audience to include any educated person who is willing to learn some new vocabulary and take a few scientific principles on faith? In fact, I tried the latter, but it was simply too detailed for the non-expert or general reader. So I have retreated to a more conventional if narrower venue, this time presuming an audience comfortable with modern biology. Iím hoping that a graduate student in any field of biology will be able to read this book with profit.

Beyond that, I am aiming for two rather disparate communities: persons interested in molecular evolution but who arenít familiar with the intricacies of blood clotting, on the one hand, and blood clotting researchers who may not have been staying abreast of developments in molecular evolution, on the other. This presents something of a dilemma in terms of strategy. Some chapters in the current version may seem overly simple to one group but may be quite challenging to the other, and other chapters may prove the inverse.

Russell F. Doolittle