Hazen's book "Gen-e-sis" is much like Ward's new one, "Life as We do Not Know It," which I read at the same time. In fact, the two authors are so similar in their interests and goals I was surprised that neither mentioned the other by name. Hazen's style is more direct, while Ward's is a little more playful. While Ward's emphasis is definitely the search for extraterrestrial life and discusses planetary potentials, Hazen's has a greater focus on what it took to have developed it here in the first place and discusses the details of origin research. 

"Gen-e-sis" is a good source for the who, what, when, where, why and how of origin science. It is an up to date compendium of what is known about modern microscopic life and the systems that it uses. More importantly for the student interested in the topic, he provides a very good description of the equipment, techniques, and personal characteristics of the researchers doing this type of work. The book would be a very good addition to a high school library, not only in its capacity as a reference on origin of life research, but for the information on the occupation of bioscience researcher. 

The author approaches his topic by examining the issues of how life arose from non-life and which of several issues was solved first: cellular segregation of "outside" from "inside," metabolism, or replication. These points are not necessarily clear to most of us. We are ourselves and live with other organisms of great complexity, not only with respect to internal organization but with respect to inter-species organization in the natural ecology of our environment. In short life on the planet has become so elaborate that it almost seems impossible that it could ever have been simpler even at the level of single cells. 

Dr. Hazen explores the current research into the ubiquity of biomolecules, how they might arise spontaneously, how they survive under different conditions, and how they might congregate into larger molecules. I found especially interesting the discussion of the spontaneous self-aggregation of lipid membranes from molecules with hydrophilic and hydrophobic ends. Certainly the formation of double layers of these molecules into more cellular like membranes in laboratory settings was amazing. 

He also discusses the RNA and DNA `worlds' and the possibility that protein or other catalytic molecules might have performed the function of replicators and metabolizers until the more complex systems used by modern life arose to take over the functions. He discusses the now rather old notion of a clay world, proposed originally by Cairns-Smith. Here clays of various types are believed to have served as templates for the natural aggregation of organic molecules which later became independent of their clay "parents" by replicating themselves. This theory still has an undeniable fascination. The possibility that rock pores might have served as the original cell "membranes" is also intriguing along this line. 

With a passing reference to the work of the Santa Fe Institute, particularly the research of Kaufmann, and of Per Bak into self organizing criticality and self emerging properties, Hazen notes that critical quantities of materials needed for life to get going may have led almost spontaneously to the origin of life. In fact it is suggested that it might do so where ever these conditions arose in the universe. 

Probably one of the best features of the book is the discussion of the problems that arise when carrying theory into research. A great theory may produce disappointing research results, may not be practicable at all, or may illuminate problems with the theory. A case in point is the issues arising with the self organizing membranes mentioned above. Here it was discovered that while membranes could arise quite simply, they didn't allow anything to pass into or out of the interior. Living cells allow a flow of materials across the membrane, usually with a gradient of some kind, prevent materials from entering or leaving by virtue of pore verses particle size, or actively transport materials into or out of the cell's interior. A cell that can't do this would either poison itself or starve to death. Such research provides useful negative information to take back to the drawing board.