How did life begin? Did it start here, by blind chance or by necessity, or was Earth seeded by extraterrestrial visitors? (And, if so, how did they arise?) Physicist and science writer Paul Davies tackles these heavy questions and more in The Fifth The Search for the Origin and Meaning of Life , a wide-ranging survey of the field of biogenesis. From the "Martian meteorite" ALH84001 to the hardy microorganisms living on--and under!--our sea beds, Davies looks for evidence pointing toward our first ancestor. His willingness to consider any possibility makes for a fun, fascinating journey through our solar system and beyond. The Fifth Miracle provides convincing arguments that life flourishes, and may indeed have begun, deep within the earth's crust, and not in Darwin's "warm little pond." And if in our planet's crust, why not in others'? Indeed, he shows that it is not just possible but likely that living organisms have passed between Earth and Mars embedded within meteorites. Davies's command of the data and his facility with explaining it to nonprofessionals give the lie to his self-description as "a simple-minded physicist" intruding in another's domain. The best scientists hate to see questions finally answered and love to see new ones raised; by that standard (and by any other), The Fifth Miracle is a first-rate book of scientific speculation. --Rob Lightner
