Life Everywhere

This book is actually in the form of a long essay defending the hypothesis that life, at least in microbial form, is widespread in the Galaxy. The author starts by trying to define life. Is it replication? Evolution? Metabolism? Next, he discusses the question of the atmosphere of the early Earth. A reducing atmosphere might produce complex organic molecules in some warm little pond. But the Earth is unlikely to have had such an atmosphere then. That leads to the question of where life originated. Near ocean vents, or on (or just under) the ocean floor? And when life originated. Over 4 billion years ago? When the Earth was still being bombarded by bolides? The author then discusses meteorites, along with the possibilities for them having brought organic molecules (or even life) to Earth. After that, there's some material on extrasolar planets, including "hot Jupiters," which may migrate right through a stellar system, wiping out all the rest of the planets in it. A very interesting section is Darling's critique of Ward and Brownlee's book, "Rare Earth." That book contains the view that although microbial life is probably widespread on other worlds, multicellular life (and especially intelligent life) will prove to be rare. Actually, that view, while a minority one, is unremarkable. After all, there is good evidence that unicellular life originated rather quickly on Earth while multicellular life took quite a bit longer. But Ward and Brownlee go further than that, claiming that several things about Earth are special and unusual: the Moon, the exact spacing between catastrophic events, being in the right part of the "habitable zone," having Jupiter to shield it from heavier bolide bombardment, having a high metallicity Sun, having plate tectonics, and being in the right part of the Galaxy! Darling presents interesting rebuttals to these points. And he finishes the chapter by pointing out that a collaborator of Ward and Brownlee, Guillermo Gonzalez, keeps finding signs that the Earth is unique. Darling asks if Gonzalez is letting his religious beliefs influence his scientific views (Gonzalez says that his views that life's origin involved the personal involvement of a supernatural creator have motivated his science and vice-versa). Um, that is a good question. Still, I wonder if that's altogether fair. Ought we ask about Simon Conway Morris, whose religious beliefs support his views on convergence? Or about, say, Fred Hoyle, with his views on panspermia? Or about Freeman Dyson, whose scientific ideas seem rather independent of his religious views? Or about, um, me? In any case, Darling continues with the debate between Stephen Jay Gould and Simon Conway Morris. Gould argues for divergionism, and says that were we to "replay the tape of life," the odds are that the chordate worm that first incorporated what became the human body plan would have been lost and there would have been no humans. Conway Morris argues f

David Darling's excellent new book does an effective job of presenting the main topics of astrobiology in a conversational writing style that is easy to read and understand. Without assuming prior knowledge on the part of the reader it clearly explains the very latest research with fascinating details and well-chosen examples that will hold the interest of experts as well as newcomers. Life Everywhere explores the conditions assumed to exist on prebiotic Earth and the various explanations for how life arose. Supporters of the various hypotheses are lumped together as "surface, sunlight" guys (who believe in Darwin's "warm little pond") and "deep, dark" guys (who believe that life arose near hydrothermal vents). Each new discovery gives a new advantage to one team or the other. The book also discusses the possibility of life on other planets and moons in our solar system, and it gives the most convincing and clear explanation I've found for the possible role of comets in the origin of life's building materials. The science in Life Everywhere is solid, and the treatment of opposing theories is open and even-handed, with the exception of the Rare Earth theory which, according to Dr. Darling, is a theory based more on theological conservatism than on scientific fact. Life Everywhere is not a large book, but it contains a wealth of up-to-date information about the new science of astrobiology. If you are interested in the scientific study of life's beginnings and limits and the search for life on other worlds, I strongly recommend Life Everywhere as the first book to read for anyone new to the subject. For anyone already familiar with the basics of astrobiology, this is still an interesting new look at a rapidly-evolving science.

This is the best book on the subject I've come across. It certainly lives up to the billing given by James Kasting, of Penn State Astrobiology Center, on the cover: "A lucid and surprisingly accurate introduction to the field of astrobiology and a thoughtful response to the Rare Earth hypothesis." Chapter 6 pretty well demolishes Rare Earth and exposes its surprising creationist roots. Elsewhere, Darling explains when and where we might expect to find extraterrestrial life, what methods we'll use to detect it, the missions and projects planned over the next 10-20 years, the latest on the controversies surrounding Mars, the Martian meteorites, Europa, organic matter in space, and extrasolar planets, and the principles that might govern life wherever it appears. He manages to cram a huge amount of information and ideas into a small space and yet it's so well explained you never get lost in the detail. It's hard to believe that the "reader" who gave the book only two stars actually read it at all. I can see how it might not be popular with those who want to cling to the belief that the Earth and humans are somehow special. But the fact is this is first-class science in a first-class package.

How can David Darling's wonderful new book "Life Everywhere" appeal to both beginners who know nothing about astrobiology and seasoned veterans who have already read many books about extraterrestrial life? The key is a massive amount of fresh, up-to-date material coupled with superb organization, an exceptionally clear writing style, and the lavish use of anecdotes and examples that make otherwise difficult material fun and understandable. Get a headache thinking about planets or moons in orbit? Visualize a spinning dinner plate with a helping of mashed potatoes in the center and a used stick of chewing gum at the rim! Among other things, David explains how rather than narrowing the search for the origin of life astrobiologists keep finding interesting new ways that life may begin. He describes the formidable survival skills of such lifeforms as "Conan the Bacterium," and he explains emerging technology that will allow us to identify Earth-like planets in other solar systems and then monitor chemical processes would be highly suggestive of life. I particularly enjoyed his sure-to-be controversial analysis of the "Rare Earth" Hypothesis", and his chance discovery of how pre-Copernican thinking may influence science today. Finding Jupiter-sized planets and mashing-up Martian meteorites are important and worthwhile scientific activites, but if you think that astrobiology is little more than this, read David Darling's "Life Everywhere" and think again!