Spider Silk: Evolution and 400 Million Years of Spinning, Waiting, Snagging, and Mating. Leslie Brunetta and Catherine L. Craig. 2011. Yale University Press.
Spiders evoke a lot of complex feelings from humans. In a survey of teenagers asked about their top fears, spiders ranked #2–right after terrorist attacks. A quick comparison of “kill spiders” to kill insects” on Google trends shows that about twice as many people are looking for ways to kill spiders. So, I know when I recommend a book about spiders to you, some of you will run away screaming.
But! For those that are interested in evolution, and can tolerate a few extra legs, there is a great new book available! Spider Silk has won several awards for science writing, and it’s easy to see why. This is a wonderful introduction to the history of spider evolution, and a great review and explanation of how evolution works. Here’s an example:
“A beneficial variation does not arise alone as a one-in-a-million chance event; rather, it is the lone survivor from a pool made up of a million other chance variations. In other words, variations do not occur infrequently, they survive and perpetuate infrequently.”
That is an explanation of one of the classic misunderstandings of natural selection! Mutations occur all the time; you are all mutants. It’s just rare that these code changes make a difference and/or persist beyond one generation.
That is where this book really shines for me as a scientist and an educator. It’s wonderful to learn about the fossil history of spiders, and all the different types of webs they make; but what I liked most about the book is the very readable and clear explanation of how mutation, natural selection, and other evolutionary factors created that diversity. This includes some of the more complex biochemistry of evolutionary change. The point mutations of amino acids that build all the different proteins in spider webs are explained in very clear non-technical language. Diagrams illustrate just how the molecular structure of spider silk allows it to function as an extraordinarily strong bungee cord.
There also are delightful humorous and historical touches sprinkled through the book, such as the use of spider silk in WWI and WWII for bomb sights. Along the way you’ll learn about the amazing diversity of webs and spiders, and how the basic spider body has changed from their aquatic ancestors.
Also there are photos (some in color!) all through the book helping the reader to visualize the different webs and how they are produced. I finally was able to see examples of some spiders that I had only read about, such as this turret web spider.