The book by Iris Fry, "The Emergence of Life on Earth: A historical and scientific overview" is not an easy read. The following is an outline of the book, and a guide to how it might be read. First, you need some basic biology background, with an emphasis on the fact that all known biology on Earth is based on the common chemical language of DNA and proteins. Thus first read carefully Chapters 7 and 8 of Goldsmith and Owen, and start reading into Chapter 9. Now for Fry's book: This is a book about science, a book about history, and a book about philosophy. It gives a very thorough description of different attempts to understand the origin of life on Earth, both recent investigations, and broader historical context. In doing so, Fry works hard to understand the philosophical prejudices and impulses that push scientists in various directions. You are not expected to be intimately familiar with the entire book, but you should start reading it over the Fall break, and aim to have it done by the end of the semester. There is much rich material here to use for your second term paper! After reading the introduction, read the *last* chapter of the book, Chapter 14. This is the longest chapter of the book, the most astronomical, and the least historical. Many of the things discussed here: evidence for life in a Martian meteorite, Europa as an abode for life, the discovery of extrasolar planets, we will discuss in detail in the weeks following the Spring break. Read the entire chapter. Now bounce back to the beginning of the book. Chapters 1-4 give an historical background that reaches back to the Greeks. The struggle here is between those who subscribe to the doctrine of "spontaneous generation" (in which living creatures arise spontaneously from non-living objects, or from rotting materials of other species), and those who said (mostly for religious reasons) that life could only be generated due to external, i.e., divine, intervention. We now know, of course, that spontaneous generation is not correct (mice are *not* created out of the soil after it rains), yet spontaneous generation was seen to be the more "scientific" approach to the question throughout much of history. Other approaches, such as the idea that all creatures contain within them a series of "nested dolls" of all future generations, are described here as well. As described in Chapter 4, it was Louis Pasteur who carried out definitive experiments that finally convinced everybody that spontaneous generation does not happen in nature. These experiments start bringing the field into the modern era, and occurred on the eve of Darwin's great work on the primacy of evolution in understanding the nature of life, and the biochemical revolution in which the components of the cell, and the molecular basis of life, started to be understood. Chapter 5 brings Darwin into the picture. The origin of life is a subject which he touched upon only briefly. Read the very interesting section on panspermia in this chapter, a subject we'll find ourselves talking about in some detail. Chapter 6 starts the modern discussion of models for the origin of life, which continues through most of the rest of the book. One frustration you will find here is that there are essentially no figures, and the reader is expected to be broadly familiar with the basic tenets of molecular biology. This is really where your reading of the biological basics will become important. In Chapter 6, you are introduced to the most important workers in the field in the early part of the 20th century, namely Oparin and Haldane. They set the stage for much of the discussion that followed. Life is based both on DNA (which carries the genetic information from one generation to another) and proteins (which carry out the metabolic processes that keep a cell alive). In living organisms, the two are intricately linked, and deciding which came first is a classic chicken-and-egg problem. Indeed, much of the differing approaches to how life got started revolve around exactly this dilemma, with different workers deciding that metabolic processes, or genetic processes, are more fundamental and therefore must have come first. Haldane and Oparin set the stage of this debate in their work, so read the chapter in this context. The next 7 chapters describe in some detail all the different approaches modern scientists have taken to the origin of life question. They are summarized and put into context in Chapter 13; you might find it useful to read this chapter at this point to give some structure to the morass of detail you are about to tackle. You won't understand everything by any means, but when you reread Chapter 13 after having made your way through Chapters 6-12, a lot should fall into place. In Chapter 7, read the discussion of the Miller-Urey experiment (which will be familiar from Chapter 8 of Goldsmith and Owen); feel free to skip the description of Fox's work (pp 83-88). At this point, the book starts getting wonderfully detailed in the description of the different ideas that have been developed. In Chapter 8, read about the discovery of the structure of DNA by Watson and Crick, and make sure you understand the distinction and different roles of DNA and RNA (you can skip the remaining part of the chapter, pp 95-99). The role of RNA is poorly explained in Goldsmith and Owen. DNA contains the genetic information in the cell, and (in eukaryotes) is contained almost entirely in the cell nucleus. RNA, which is quite similar chemically, and has the potential to carry genetic information, is actually quite a bit more versatile. One of its roles in cells is to carry the genetic information from the DNA in cell nuclei out into the protoplasm, where proteins can be synthesized. But it can also catalyze various reactions, and do some of the metabolism of the cell itself. This is important; RNA to a certain extent bridges the gap between the "chicken" and "egg" of the functionality of DNA and proteins, and thus it has been hypothesized as a possible mechanism to get life started. Feel free to skip Chapter 9 on Manfred Eigen's model of what he called 'quasi-species'. A wonderful subject, however, on which to write a term paper! Chapter 10 has got a lot of good stuff in it; you should read it all. It ties to questions of the nature of the early Earth, hydrothermal vents (which I find fascinating); Cairns-Smith's ideas for getting life started on mineral crystals, and other juicy topics. Chapters 11 and 12 set up the 'genetics vs. metabolism' debate. Chapter 11 explores the notion, hinted at above, that the versatility of RNA allows it to play a major role in the origin of life. This is not an easy chapter to read, but try to get through the first half (i.e., through Page 142). Chapter 12 starts with a discussion of two quite mathematically sophisticated approaches to the origin of life (one of these is from Freeman Dyson, who works at the Institute for Advanced Study in Princeton). Feel free to skip this discussion, and start at page 162 with Wachtershauser's ideas (similar in spirit to those of Cairns-Smith in using a crystalline template for life to get started). Don't worry about the details; this is 17 pages of dense prose, that cries out for a few explaining diagrams. But by this point, you have a sense of the range of different crazy ideas scientists are going after to explain how life got started. Chapter 13 tries to make some sense of all the different ideas that have been put forward; it is perhaps the most philosophical of the bunch. Indeed, I suggested above that you read this Chapter before tackling the details in Chapters 6-12. If you did so, reread it now; you will see that a lot of it will make more sense now. It is a long chapter, 40 pages; please don't feel responsible for every detail! This chapter has quite a bit of discussion of the creationist point of view (whereby life got started by the intervention of a divine being). It is an attractive approach in many ways, given the sheer difficulty of getting such a complex thing as life started. This is the 'scaffolding' problem described starting on page 185. It will be interesting to have a discussion of whether you find Fry's discussion convincing.