| I have noticed that some biologists have a kind of arrogance about chemistry. "I don't have to know the chemistry!" To a certain extent, it's true that in some branches of biology you can have a very productive career without ever really knowing the chemical details that underlie the biology you're working on. However, a poor grasp of chemistry can also lead you to fall on your face in an embarrassing way, and that's what happens at one point (at least!) in "Spark of Life." Authors who get the chemistry right in writing about the origin of life can extend previous theories in interesting ways. Christian de Duve, the Nobel Prize winner who wrote "Vital Dust" does exactly that, presenting the idea that protein-based life preceded an RNA takeover. The current enthusiasm for an RNA world as the original form of life on Earth is mostly being promulgated by people who don't really understand how nucleotides behave. As I said before, this includes a lot of biologists. Robert Shapiro's books (he gets it right, too) explain clearly how totally unlikely it is to have rich concentrations of RNA nucleotides lying around in puddles waiting to combine into nascent RNA polymers. On the other hand, this is a very likely thing to happen in cells that are using ATP and other triphosphates for energy storage. There they are, it's easy to polymerize them. Getting the chemistry right doesn't guarantee you'll get the theory right -- Michael Behe gets the chemistry right, as well. But getting the chemistry wrong can lead down the path of error. I think if Lynn Margulis really understood the difference between Diphytanyl ethers and fatty acid bilayers, she'd see that Archaea are wildly different from "regular" Eubacteria. OK, so this is a review of "Spark of Life." What Wills and Bada did that made me lose all confidence in their knowledge of primordial soup is this. There are four "bases" used in RNA -- Uracil, =Cytosine=, Adenine, and Guanine. Any undergraduate taking Biochem or MolBio knows this. But Wills and Bada and their editors and readers apparently do not. Thus the statement on page 109: "Another example is cytosine, an essential nucleobase of DNA. ... cytosine is unstable and decomposes quickly. It may not be a coincidence that RNA, which probably appeared before DNA, uses the more stable molecule uracil instead of cytosine." Now, this isn't a typo, or a "word-o." There is nothing in the biochemistry of RNA that corresponds to the paragraph above. RNA uses both Uracil and Cytosine. Thymine is used in DNA rather than Uracil -- but the issue is not stability but information. Thymine has an extra methyl which allows it to be distinguished from the Uracil produced when Cytosine inevitably breaks down. So, I am supposed to learn about the primordial soup from people who can't remember what RNA is made of?? There are other irritations as well. The use of "Darwin" to personify selective processes is juvenile, precious, and off-putting. An example from page 112-3: "organic molecules ... awaited the firm hand of Darwin, who would decide which of them would 'live' or 'die'." I can't see who would enjoy this book. I read avidly about the origin of life but how can I believe Wills and Bada have any grip on this material given their chemical howler?? I am basically amazed at the positive reviews the book has received so far. I don't find it useful at all. |