Carl Zimmer's "Microcosm: E. coli and the New Science of Life"

This is an excellent book. Lots of interesting details. It covers E. coli from discovery in 1885 up to today's synthetic biology which uses the techniques developed with E. coli to develop manufactured life, new microbes that use amino acids not in nature's list of 21 but 80-some that researchers have now developed and learned how to encode and get synthetic microbes to build upon.

Not only is this a wonderful biography of the researchers and their thoughts. It present lots of ideas that are new to me. I particularly enjoyed:

• Microbes like E. coli "age". They have done experiements that trace the splitting of microbes and can show that those with the oldest half of the split shows signs of aging and die before those that are younger. So aging is built-in even before you get to large multi-cellular organisms.
• There is a gene, microcephalin, that can be traced to Neanderthals, that has spread widely throughout modern humans: 70% of all moderns. But this is a gene that clearly is not from the line of descent of modern humans. It entered through sexual contact with Neanderthals and because of its benefits -- playing a central role in the development of the brain -- it has spread quickly in modern humans.
  
• Infamous microbes that cause diarrhea, such as Shigella, end up being strains of E. coli.
• There are wonderful details of E. coli O157:H7 which is a strain of E. coli that is harmless to cattle, but has toxins that cause great harm to humans. There are 5.5 million base pairs in O157:H7 while K-12, a harmless E. coli, has 4.6 million. So there are vast differences between these two E. coli strains.
• He provides an excellent discussion of the ethics of genetic engineering that points out that the issues are complex and that there is no basis for drawing a line that limits "ethical" experiments to some God-given demarcation of species. As he points out, there is natural process of horizontal transmission of genes by viral infection that does not respect species "boundaries". In the microbial world, horizontal gene transmission plays a very large role. In multicellular organisms it plays a much smaller role, but it still exists. All this is contrary to the simplistic arguments of those who protest Frankenfoods or transgenic experiments.
  

Update 2009mar03: Here's a nice video book review for this book: