Customer Reviews

Origins of Life

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First published in 1985, Origins of Life by Freeman Dyson, is a great introduction into the most accepted theories on the origins of life. It was almost universally assumed that the first organisms sustained themselves, in a very hostile world 3 eons ago, by replicating themselves. A brief introduction into the three main theories of replication, a precise chemical process a molecule uses to make an exact copy of itself, is laid out in the first two chapters. Dyson then presents his own theory as to the possibility that the first organisms didn't replicate, but sustained themselves via metabolism, in the form of simple enzymes. He theorized that replicating organisms used the pre-existing enzymes as hosts later on. In chapter three, he presents a "simple" mathematical model as a basis for biologists to create their own experiments to, if nothing else, prove him wrong (Dyson is a theoretical physicist and this work attempts to bring together thinking from different scientific fields). The last chapter was the best, bringing philosophy into play. For example, he debates the notion that replication of human behavior is not a very exact process, but very fault tolerant instead. In fact, he surmises the first replicating organisms were probably sloppy at the job. If that notion excites you, buy this book! Mr. Dyson attempts to make this book readable for the layman, but does not define what monomers or nucleotides are. This book is not for everyone. A rudimentary understanding of biology would help, but I made it with only a dictionary. I didn't even attempt to follow the math in chapter three, and the author was apologizing for its simplicity!

In 91 pages of text Freeman Dyson says some surprising and wonderful things, and turns around some conventional notions about the place of replicating molecules such as DNA and RNA in early life. His view is that they came later - perhaps much later - after metabolism was established in cells that reproduced sloppily and approximately, but had robust-enough homeostatic mixes that a split was usually successful. This view was approximately that of a Russian named Oparin 75 years ago, but the dazzle of the genome has turned almost everyone to thinking that precise replicators had priority in the development of life over haphazard metabolizers.

Dyson does not depend on hand-waving and vague argument to draw these conclusions. He reviews what is known and the main extant theories of life's origin, then introduces his own, using a "toy model" that abstracts the chemistry and draws conclusions about steady-state solutions that might work. As befits a great theoretician, it is an elegant and powerful bit of theorizing, but does not wander from the constraints of the chemistry -- as far as he knows. But Dyson is clear that the point of his model is to stimulate experiment, and that organic chemists will be the ones to judge the usefulness and viability of his assumptions.

Unless you are a physicist, you won't follow some of his work in solving for the model, but you can trust the math and the physics when it comes from Freeman Dyson. Just glance at the equations and graphs, but follow the words in his model chapter and get a real feel for the kind of system that proto-life might have been.

He makes a good case for the essence of life being complexity, and that the conceptual purity and rigor of the gene has distracted us from the "tangled bank" that life at all levels, from bacterial cell to ecosystem to economy, seems to exemplify. Error tolerance -- being able to carry on in the midst of junk and in spite of "mistakes" -- seems to be more characteristic of life than exactness. That's a pleasing notion in an uptight age.

We're used to books that give answers. We want to be spoon fed, and often whine when the answers are not sugar coated as well.

The books about the origins of life that I've read (De Duve's "Vital Dust," Margulis' "Early Life," Gribbon's several books, Crick's pan-spermia, the anthropic principle...) follow the usual pattern. They start at different stages of the origins of life, but they all:
- expound a theory as if it were universally agreed to be true then
- explain how the process progressed whether from stardust or extra-terrestrial sources, oceanic amino acids or bacteria-like organisms.

Well, Freeman Dyson does it differently. He starts with good questions. Questions, when formulated well, help us to think and arrive at better answers. He asks about the first living cells:
- Did replication come first or
- Did metabolism come first?
- Did those two processes happen simultaneously?
- Did they happen independently or were they correlated or causative...?
- Which process might be 'better' or 'worse' if it happened first?

He reviews the well-known research (natural selection, statistical methods...) and how well they may be able to answer these questions. Then he tells us his preference and why. Why? Because it helps us to think further.

Then he says that being a physicist (and a mathmatician who, at age 17, devised the pattern for cluster bombing that would create a self-accelerating firestorm. His theory was tested on Dresden and proven to be very effective), he does not know about biology and with that disclaimer, built a 'toy model' to help us think through ways to arrive at conclusions.

The third part of this book goes into the 'fidelity of replication (or error rates), and an analysis of the smallest number of self-organizing molecules that still 'work.' This seeming tangent is of special interest to me because it furthers my quest to learn how we acquired mitochondria and how they work now, with so few DNA of their own. And also what might be the evolutionary future of extremely simple organisms that are formed into colonies such as some sea jellies?

This book made me think so hard that I don't actually remember its conclusions. It's a short book so only took a few evenings to read, even including the periods I had to put it down to let my mind digress down a path that was triggered by the book, but I might be thinking about it and studying the questions that it raised for a very long time.

Dyson is always worth reading. And this book is a very useful introduction to some theories about the origin of life. Dyson starts by stating three of them. The first theory is Oparin's, where cell frameworks originate first, enzymes second, and genes third. The second theory is Eigen's, where genes are first, enzymes second, and cells third. And the third theory is from Cairns-Smith and has clay first, enzymes second, genes third, and cells fourth.

As Dyson explains, for the Eigen theory to work, four "catastrophes" need to be avoided. First is the "error catastrophe," where there are simply too many errors in replication of long RNA molecules. Second is the "selfish RNA catastrophe," where an RNA molecule mutates and dominates the scene, but the mutation takes away its critical role as a catalyst. Third is the "short-circuit catastrophe," where a mutated RNA molecule catalyzes the wrong reaction (a later one in a chain than the proper one). Fourth is the "population collapse catastrophe," where one simply runs
out of a critical component. Dyson wants to pursue other something other than the popular Eigen theory, not just to be different, but also to try to avoid the error catastrophe. That's why he constructs a "toy model" for the Oparin theory that can allow up to a 25% error rate.

Dyson concludes with a few "open questions." One of the most fundamental is, "Given that a population of molecules is able to maintain itself in homeostatic equilibrium at a steady level of metabolism, how many molecular species must the population contain?" This leads to the question, "What is the smallest population that is able to constitute a self-replicating system." Dyson tells about the experiments of Spiegelman (which produced a virus RNA with only 220 nucleotides) and of Eigen (which produced one with 120 nucleotides).

This book is easy to read and informative.

An excellent book about the origins of life. Dyson does an excellent job of clarifying the main issues concerning the origins of life while introducing some of his own ideas. He keeps it all together in a very tight package.

His own theory about the origin of life is quite interesting and probably could be expanded upon, especially in light of other, similar mathematical treatments such as those of Manfred Eigen.

my eyes glazed over on the chapter with the math but i was still able to get a decent overall review of the key issues..he has his own favorite theory but acknowledges opposing ones..i respect that. i feel more ready to tackle other books on the subject, as a result

Great short book. A good way to spend an hour and learn a lot on the way.

I love science fiction, and this book is science fiction, but with one serious flaw: The author is a physicist and his lack of training in chemisty, genetics, and biology is an embarrassment throughout the book; which I guess is why he kept it to 90 pages; he ran out of things to say. Having a physicist explain biology is like having a biologist explain physics. Hello?! Does this make sense? No, and neither does this book.