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In this groundbreaking book, Lynn Margulis and Dorion Sagan present an answer to one of the enduring mysteries of evolution--the source of inherited variation that gives rise to new species. Random genetic mutation, long believed to be the main source of variation, is only a marginal factor. As the authors demonstrate in this book, the more important source of speciation, by far, is the acquisition of new genomes by symbiotic merger. The result of thirty years of delving into a vast, mostly arcane literature, ...
In this groundbreaking book, Lynn Margulis and Dorion Sagan present an answer to one of the enduring mysteries of evolution--the source of inherited variation that gives rise to new species. Random genetic mutation, long believed to be the main source of variation, is only a marginal factor. As the authors demonstrate in this book, the more important source of speciation, by far, is the acquisition of new genomes by symbiotic merger. The result of thirty years of delving into a vast, mostly arcane literature, this is the first book to go beyond--and reveal the severe limitations of--the "Modern Synthesis" that has dominated evolutionary biology for almost three generations. Lynn Margulis, whom E. O. Wilson called "one of the most successful synthetic thinkers in modern biology," and her co-author Dorion Sagan have written a comprehensive and scientifically supported presentation of a theory that directly challenges the assumptions we hold about the variety of the living world.
|Pt. 1||The Evolutionary Imperative|
|1||Darwinism Not Neodarwinism||3|
|4||The Natural Selector||67|
|5||Principles of Evolutionary Novelty||71|
|Pt. 2||The Microbe in Evolution|
|6||Species and Cells||81|
|7||History of the Heritable||89|
|Pt. 3||Planetary Legacy|
|9||Eukaryosis in an Anoxic World||139|
|12||Chromosome Dance: The Fission Theory||191|
|13||Darwin Revisited: Species in the Evolutionary Dialogue||201|
Posted February 11, 2003
This is an important book because it shows the many many problems with neoDarwinism (especially the claim that the source of new genetic information is mutations). As the title indicates, the authors propose a new theory, namely symbiosis, the exchange of genes among life. Symbiosis is, in the words of the author, the big provider of the raw material that natural selection can then select from. The lethal flaw in this idea (which the authors could not deal with) is their idea explains the survival of the fittest, but not the arrival of the fittest. Where did the information in the genes come from in the first place? It is well known that bacteria can exchange genes (as I stress to my microbiology students) but no evidence exists for a means that can create the information in the first place. This must be explained before neoDarwinism, or its many competing theories such as symbiosis, can explain the from the goo to you by way of the zoo theory. Otherwise, this was an excellent easy to read book full of interesting material of interest to microbiologists and cell biologists (my field).Was this review helpful? Yes NoThank you for your feedback. Report this reviewThank you, this review has been flagged.
Posted January 6, 2003
Lynn Margulis has been a maverick all her life. Early in her career she shocked other biologists by arguing that the mitochondria that power our cells and the chloroplasts that let plants transform solar into chemical energy were once free-living bacteria. As soon as scientists isolated and decoded the scraps of DNA in those vital organelles, they found that Margulis was right. She went on to develop Serial Endosymbiosis Theory, which attempted to trace the development of all creatures with nucleated cells, from yeasts to humans, to a series of genetic mergers between different life forms. According to Margulis, all the familiar family trees of life, which show only radiating branches, are wrong. Ancient roots and current branches cross and flow together to form new species. To Margulis, nature is far more promiscuous and creative than most biologists dream. Her new book, Acquiring Genomes: A Theory of the Origins of Species, extends and deepens that argument. Margulis sets out to show that new species rarely if ever appear as the result of mutation, isolation, genetic drift or population bottlenecks--the standard explanations of neo-Darwinists. Instead she maintains that the major engine of evolutionary change, the source of most of the novelty that natural selection edits, is symbiogenesis--the acquisition of whole genomes as the result of symbiotic associations, "consortia," between different kinds of organisms. (Knowing that some people will seize on her thesis as an attack on the theory of evolution as a whole, Margulis makes it clear that she fully supports Darwin's great discovery of the mechanism of natural selection. She simply thinks that neo-Darwinists have failed to recognize the enormous creative power of genomic mergers.) Readers familiar with Margulis' earlier works will recognize her vivid, personal and sometimes impressionistic writing style. I found this book, co-authored by her son, Dorion Sagan, to be clear and accessible. Starting with Chapter 9, where Margulis presents her latest ideas on the symbiotic origin of the nucleus itself, things get a bit technical. Margulis makes every effort to help readers through the thicket of important, but at times tongue-twisting terms, and supplements the text with an excellent glossary. Margulis also presents the findings of several other researchers whose work supports or relates closely to her own. Readers may or may not close the book convinced that Margulis is right and the neo-Darwinists are wrong. But they will come away with a vastly deeper understanding of the pervasive nature and power of the microbial world, and of symbiosis. Margulis reveals a hidden side of nature, in which microbes have generated most if not all of life's metabolic machinery, in which vastly different life-forms form a myriad of intimate associations, and in which the acquisition of entire genomes powers great evolutionary leaps. Anyone with a deep interest in biology will gain important insights from Acquiring Genomes. Robert Adler, author of Science Firsts: From the Creation of Science to the Science of Creation (Wiley & Sons, 2002).Was this review helpful? Yes NoThank you for your feedback. Report this reviewThank you, this review has been flagged.
Posted August 14, 2002
I heard Margulis on the radio. She said that truth is stranger than fiction: the cells of our bodies have multiple bacterial ancestors--we are like mermaids, griphons, phoenixes and other combined beasts once thought real. But there is more: new species evolve by the coming together of separate genomes. I read the bad reviews and had to put my two cents' worth in: this is a great book by a great scientist, and the first to show how species really evolve. There have been several books on symbiosis but none on speciation by symbiosis. Did you know that there are beetles that cannot fly without their inherited bacteria? That butterflies probably are a combination of more than one species? That there is mounting evidence that new species in birds and mammals come from the chromosome-splitting activity of trapped but still frisky former bacteria? I noticed in Stephen Jay Gould's new book how he describes cancer as a natural state to which stressed cells revert, becoming more like their microbial ancestors. This is a Margulis idea. I did not find the book bitter or disorganized but full of examples. The book doesn't pull punches--but if you're a scientist after the truth, rather than looking to kiss... for grant applications and acceptance, you'll be more interested in the evidence than the latest theory. And the evidence is that species evolve not (as the neodarwinists have long held) by random variation, but by symbiosis, 'a genome at a swallow.' That may be hard to swallow if you've studied biology in the last twenty years, but apparently it is correct. Truth is stranger than fiction.Was this review helpful? Yes NoThank you for your feedback. Report this reviewThank you, this review has been flagged.