Though Professor Carroll's book is one of the most challenging texts of popular science I've read to date, it is worthy of the time spent deconstructing it. I've not encountered a single book that has gone farther in explaining the mechanics behind the diversity of species that exist on our planet.
Since Charles Darwin lifted the curtain on evolution, biologists have been striving to uncover the essence of life's diversity. Why is a bird a bird and an elephant an elephant? Geography can't be the only factor involved in the evolution of such wildly different creatures. The answer, explains Professor Carroll, a molecular biologist, lies in our genetic structure.
Bodies have blueprints. These aren't plans hidden away in some cabinet somewhere. The plans exist inside the embryo, a set of root instructions for how the embryo should develop and what it should develop into. The executors of this body plan are a set of genes known as Master Genes. Imagine that the body, as it grows, is like an office tower under construction. The genes which build the body are the various crews working on the tower. The Master Genes, meanwhile, are the foremen of these crews, instructing the grunts on where to put the windows, how long the hallways should be, and generally overseeing development. Simply put, every embryo needs a road map in order to develop into something that resembles its parents. The genes that build toes are fundamentally the same as the genes that build fingers. It's the Master Genes that ordethem to build fingers on hands and toes on feet. and so, without the road map, the organism would become a blob of disordered features that would soon expire from sheer chaos. Master Genes give us our shape and, in the process, explain why a bird is a bird and an elelphant is an elephant. Body plans morph over evolutionary time. Master genes mutate, or are overwritten, issuing different instructions to the footsoldier genes which, in turn, create a different body plan.
This is a massively oversimplified version of Professor Carroll's gripping explanation of the basics of both our world and his field of Evolutionary Development, a field which seeks to lay out the fundamental rules of life, its variety and how it evolves from one form into another. He also discusses other components of evolution, their discoverers, their experiments and their breakthroughs, providing a number of photographic aids to help along the newcomer. More over, it is Professor Carroll's determination to stay within the boundaries of common English that allows neophytes like myself to enjoy his work so much. As fascinating for those interested in evolution as it is for those seeking a better explanation for how our planet teems with such a diversity of life. (4/5 Stars)
No comments:
Post a Comment