Spider Silk: Evolution and 400 Million Years of Spinning, Waiting, Snagging, and Mating chronographs the evolution of spiders alongside a, if not the, key to their success: silk. This book is aimed at anyone with an interest in natural history, and provides a fundamental course on arachnology, evolution, and genetics. It therefore serves as an ideal introduction to spiders and a tempting peek at the field of silk research that I hope will leave the reader forever fascinated and enthused by these wonderful web weavers.
Leslie Brunetta is a freelance writer whose articles have appeared in the New York Times, Technology Review, and the Princeton Alumni Weekly, as well as on National Public Radio and elsewhere. Catherine L. Craig, a research associate of Harvard University and author of the monograph Spiderwebs and Silk, is an internationally recognized evolutionary biologist, arachnologist, and authority on silk.
A silk researcher myself, I can appreciate how, much like an orb-weaving spider's web, the authors attempt to combine several different threads, each with a specific function, into a structure carefully designed to ensnare the mind of the reader. They begin with one of the strongest, the scaffolding or dragline silk; a discussion about the genesis of the arachnids based on fossil records and a detailed history of evolutionary theory. From this scaffolding they then spin the underlying framework through their description of how minor changes in the structure of silk molecules have endowed the spiders with new silks to use and thus conquer their environment. This is then replaced by a captivating spiral of stories over the second half that delves into how silk plays an integral role in a spider's life from dispersal as young to capturing the next meal and mating.
This book is the result of a dialogue between a scientist (Craig) and nonscientist (Brunetta), and is essentially a more accessible version of Craig's excellent academic text Spiderwebs and Silk. The authors achieve the difficult task of conveying many high-level yet fundamental biological concepts while preventing the reader from becoming entangled in specialized language and theories. On occasion, however, this conversation becomes tangential, and the flow of the narrative is sometimes lost as the authors revisit concepts that would have been better introduced much earlier (specifically, the chapter on evolutionary-developmental biology). Yet these digressions are rarely laborious, and to the uninitiated, they serve as a good source of background knowledge that enhances the appreciation of the subject matter.
I particularly enjoyed the wide range of examples drawn from across the world of arachnids that build upon each other subtly, yet convincingly, into a cohesive and logical hypothesis for the evolution of web structures and how they represent evolutionary trade-offs between a range of competing ecological and genetic factors. This was all explained in a well-conceived manner and endows the reader with unique insights into the mindset and approaches taken by an evolutionary biologist.
Those who read Spider Silk in the hope that the mysteries of silk's superior mechanical properties will be revealed may be surprised to learn that we don't really know (yet). I was relieved by this truly refreshing admission, as I work in a field where most would have you believe that this mystery is solved with every new paper. I do feel, however, that the authors lacked conviction with respect to our current understanding of structure—function relationships in silk. Their explanation tends to focus too much on the protein sequence and, in my opinion, not enough on the other, equally important aspects of silk production: the coevolution of the glands (morphology) and how silk is spun (behavior). For example, the same silk protein pulled through the same silk duct at different speeds produces fibers with very different mechanical properties, something eminently more phenotypically plastic than chancing upon a new beneficial mutation. However, I think this merely highlights why we are so fascinated by this material; its elusive qualities are just out of our reach, and only through continued research and inspiring the next generation of scientists from all disciplines to tackle this important and interesting issue will we be able to “unravel” the web.
In summary, Craig and Brunetta successfully walk the thin line between education and entertainment, providing a solid foundation from which the reader can balloon into the world of the arachnids.
