Origins of Life (CANTO)
By addebook • Jun 25th, 2008 • Category: Biology •
•
Origins of Life (CANTO)
Origins of Life (CANTO)
By Freeman Dyson
Publisher: Cambridge University Press
Number Of Pages: 110
Publication Date: 1999-09-28
ISBN-10 / ASIN: 0521626684
ISBN-13 / EAN: 9780521626682
Binding: Paperback
How did life on Earth originate? Did replication or metabolism come first in the history of life? In the second edition of the acclaimed Origins of Life, distinguished scientist and science writer Freeman Dyson examines these questions and discusses the two main theories that try to explain how naturally occurring chemicals could organize themselves into living creatures. The majority view is that life began with replicating molecules, the precursors of modern genes. The minority belief is that random populations of molecules evolved metabolic activities before exact replication existed and that natural selection drove the evolution of cells toward greater complexity for a long time without the benefit of genes. Dyson analyzes both of these theories with reference to recent important discoveries by geologists and chemists, aiming to stimulate new experiments that could help decide which theory is correct. This second edition covers the impact revolutionary discoveries such as the existence of ribozymes, enzymes made of RNA; the likelihood that many of the most ancient creatures are thermophilic, living in hot environments; and evidence of life in the most ancient of all terrestrial rocks in Greenland have had on our ideas about how life began. It is a clearly written, fascinating book that will appeal to anyone interested in the origins of life.
Summary: Good questions are real thought-provokers
Rating: 5
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.
Summary: Short but interesting
Rating: 5
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.
Summary: Concise introduction to the origin of life.
Rating: 5
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.
Summary: Bright Light
Rating: 5
Great short book. A good way to spend an hour and learn a lot on the way.
Summary: Like A Physicist Out of Water
Rating: 1
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.
Free download Links
http://mihd.net/bd6g4l
http://rapidshare.com/files/94161280/Origins_of_Life__Second_Edition.rar.html
http://www.filefactory.com/file/fe9f21/
Related Posts
