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By Dennis D. McDonald

Cloning, evolution, and the Human Genome Project are often in the news. One of my 2008 New Years’ Resolutions was to learn more about genetics and molecular biology. I had resolved to “get smarter” about DNA and its role in evolution and in generation-to-generation stability and inheritance.

Despite its brevity, this book manages to be profound, clear, and extraordinarily thought provoking. Published in 2000 by Harvard University Press, it looks back on a century of genetic research that started with ponderings about the mechanisms of inheritance, exploded in mid-century with the description of the helical structure and role of DNA, and concluded with the dawning realization that much of what we thought we understood about DNA and molecular biology was either wrong or incomplete.

Keller writes that the role of DNA in reproduction is significantly more complex than had been thought in the 1950’s and the 1960’s. Based on her meticulous research and a focus on a series of important questions, she shows how the notion that helical DNA functions as a simple recorded “template” for generational transmission of biological characteristics is a gross oversimplification. In fact, how DNA operates and is controlled in reproductive processes is so complex and mysterious that the very nature of the existence of “genes” is called into question.

I’ve italicized “and is controlled” since that question lurks behind much of this book. What is the mechanism that controls how DNA operates? The author discusses in clear and elegant prose a lengthy list of research findings that seem to show that we do not yet know.

This is not, however, a negative or pessimistic book. It is, instead, an intelligent assessment of our state of knowledge about one of the most profound and mysterious phenomena in the natural world. Reading about DNA related operations, in the light of current [circa 2000] knowledge, I could not help but shake my head at the astonishing complexity of the mechanisms that evolution has delivered.

At the same time, I cannot help but be encouraged at the intelligence and creativity of those who study and advance humankind’s knowledge of such phenomena. I shall therefore attempt to continue my reading in this field; hopefully additional books of this calibre are available.