Customer Reviews

Symbiotic Planet a New Look At Evolution (Science Masters)

5 star:		(3)
4 star:		(13)
3 star:		(3)
2 star:		(1)
1 star:		(0)

 

 

I am a great admirer of the author, who is one of the most creative biologists alive today, and a tireless popularizer of the brilliant and exciting ideas that define her career. For fans like me, this book is a must, as it offers tidbits about the author's life, including her marriage to Carl Sagan. It is also valuable in that it seeks to respond to criticisms of the Gaia hypothesis. But for those new to Margulis' work, I would recommend starting with Microcosmos, which she wrote with her son Dorion Sagan, a truly wonderful book that everyone interested in biology or the environment should have on their shelves. If Microcosmos doesn't grab you, don't bother with Symbiotic Planet. If it does grab you, then you'll probably want to go on to this book and others by Margulis.

Some years ago, Margulis promoted a new concept in evolution. Complex life developed from the merging of microbial forms of life. Elements of the cell such as mitochondria, chloroplasts and other organelles came from small, simple lifeforms invading larger cells. The idea was a long time in gaining acceptance, but is now part of conventional evolutionary texts. In this book, she expands her earlier work with some accounts of her life as a scientist and wife of Carl Sagan. She also goes beyond her earlier work to advance a new thesis on the accelerator of evolution - sex. While many of her ideas are presented in more detail elsewhere, this book is a good, quick introduction to fuller accounts of her thinking.

Margulis is an innovator - forceful in imparting her ideas. She portrays herself as a rebel from early in her career, arguing here that she was sceptical of "genes in the nucleus determin[ing] all the characteristics of plants and animals." Her misgivings received scant support, however, without a replacement thesis. She found one in symbiosis - the association of multiple organisms. It took many years of investigation, including initial rejection of her attempts to publish, before the idea of SET [Serial Endoymbiosis Theory] found acceptance. So much attention had been focussed the DNA in the cell nucleus that organelle structure and function had been essentially overlooked as irrelevant. That these organelles might have been independent organisms at some point was too novel. Her account of the struggle to gain recognition is related as one of dogged persistence, nearly devoid of outside support .

Moving through an interesting discussion of life's origins, she dismisses the notion that forms of nucleic acids arose before simple cells. She finds the natural occurence of lipids [fats] as the more likely precursors of complex life, with RNA and DNA arising as a way to give these fat globules more survival ability. As with her earlier thesis, this one will generate controversy, something Margulis seems nutured on.

Her proposal about the emergence of sex will come as a surprise to most readers. In a word, she suggests sex resulting from cannibalism. In Margulis' view, certain microbes under stress, notably the absence of food, turned on each other for survival. The cannibalism was not always fully consummated, she suggests, but the beginnings of mixing genetic material was begun in the process. Incomplete cannibalism could lead to the formation of a new, more complex organism. If this process occurred often enough within a compatible group, the new organism, obviously larger than its predecessors, would be more fit to compete.

In conclusion, Margulis makes a strong case in favour of James Lovelock's Gaia concept. This might have been a non-sequitor in the hands of someone less able to deal with novel ideas. Margulis stresses that Gaia has been mistakenly viewed as Earth's biosphere acting as a single organism. She argues that Gaia really means a global network - a "system of organisms." The Gaia concept means the elements of the "system" are tightly entangled and extinctions weaken the structure. If the extinction rate exceeds the rate of recovery the system is endangered. It's interesting to note in light of her definition that the Gaia website still refers to it as a "superorganism," not a "system of organisms." This disparity doesn't detract from Margulis' presentation, which is admirably presented. She offers enough graphic support for the text to clarify or enhance her themes. In all, this is a fine mind-opener in thinking about the development of early life. Readable by anyone interested in life's history and processes.

Readable in a few hours, this book gives a quick introduction to a concept tremendously important to understanding the evolution on life on earth. I would have liked more extensive discussion of SET, with respect to the protoctists; the recognition of the development of these organisms from the symbiosis of various bacteria laid the groundwork for the understanding of symbiotic relationships in plants, animals, and fungi, which Margulis discusses in later chapters, yet the details of it take only a couple early chapters. Other volumes in this series are longer (some 170 pp.), and this one could have been, too. The clarification of "the Gaia hypothesis," in the last chapter, is very strong, and welcome; undergirding it is Margulis's insistence (throughout the book) on unsentimental and rigorous scientific thinking. The book does contain flaws. Editorial errors show a lack of careful proofreading (e.g., the date of the rediscovery of Mendel's work is given as 1990). Many sentences would have benefitted from more use of commas. More illustrations (e.g., of the structures of cells and organelles, mitosis, and meiosis) and summary equations for various metabolic processes, as well as a glossary, would make the book more accessible and useful to those who retain only a hazy knowledge (and that probably out-dated) of these things. Finally, Margulis takes too much the stance of the battered, then embraced and finally vindicated iconoclast, and seems rather too smug (as when she refers to "my SET theory"). It's just not attractive, and could have been toned down; it's obvious that she's brilliant. My criticisms, however, are relatively minor, and I recommend this book enthusiastically.

I um'd and ah'd about how many stars to give this book. If I was just assessing the importance of Lynn Margulis's scientific work it would definitely receive five stars. Margulis is an underrated genius. Her work on symbiosis and evolution is extremely important. It reminds us that evolution is far more complex than a simple choice between neo-Darwinism and Lamarckism. Her connecting of her ideas to the Gaia hypothesis of James Lovelock is inspired. Unfortunately, this book shows why she might be getting less exposure than she deserves - it is not terribly well written. In fact, it reads as though it was produced in a hurry with almost no editing. Further, there are diagrams in the book which have no stated connection to the text (OK, you can work it out for yourself, but it still comes across as shoddy). Having said that, the style perhaps gives an insight into the person - clearly Margulis is a battler for her ideas. Its good to have something to read by her that is less weighty than her other seminal but hefty works. Sometimes here she can be very funny. I particularly liked her comments on James Lovelock's dislike of the patenting process. So in all, four stars - a very good book that with a little tightening up could be great.

To a large extent I agree with other reviewers in that the book is a quick read with some minor if annoying problems such as the obscure habit of inserting diagrams which appear to have no direct link to the text. If they do then it is not always obvious or well outlined. One also gets the impression the diagrams are very detailed for an audience of laymen and seem to be taken from medical texts, again one feels as though the book had been put together quickly, possibly under pressure from a publisher or some other reason.

Nonetheless Lynn Margulis is an accomplished biologist often highly underrated and fully deserving of her honours in the field where she developed the earlier idea of symbiogenesis of bacterial partners to form modern cell structure. One reviewer mentioned that she gives the impression of being self complementary and acting like an undertdog. I have personal experience of just such a scientist and one gets the feeling that a strong degree of self confidence, sometimes appearing as self congratulation or a seeming over emphasis to self advertise, is necessary to survive the sometimes personal barbs directed at an innovative scientist from others in his/her field, a healthy ego helps to persist in an environmemt which can go so far as to loose jobs and even give rise to ill health.

The book itself is very enjoyable and the personal anecdotes from Margulis's life lighten the story and help to put the reader in touch with the life of the scientists rather than being too impersonal. This also includes the fascinating characters represented by other scientists. Margulis strongly clarifies the concept of Gaia theory developed by James Lovelock in the seventies and removes the mystical element which a public lacking a spiritual element in their lives attach to it. Absolutely wonderful science and makes me want to check out more of her books and research.

"Symbiotic Planet" may sound to the average reader like just another attempt to "classify" life on our little Earth. This would be an error. This book, as is typical of Dr. Margulis' writing is precise, complete, and allows the reader to easily follow along this amazing journey through time and life itself. I have read, as well as reviewed a number of Dr. Margulis' books through the years, and stand in awe at how she can "break down" what to myself seems an incredibly complicated idea, into plain common examples. Her writing captivates the mind of the reader, to the point that it seems impossible to put down. I am a very slow reader-yet I finished the book (the first time) in a single day. One cannot stop reading it is just that fascinating! There is little I can say that would be nearly adequate to properly describe this book. The reader will decide for themselves that is really is a great read and a great book to keep as reference. It really is as simple as that.

Let's hear it for the bugs-not your creepy-crawlies, but bacteria, the be-all (and possible end-all) of life on Earth, according to Margulis. Here she describes the once radical theory that cells have incorporated bacteria to mutual advantage and uses that as a springboard to summarize a still more radical theory of how species evolve. She calls it serial endosymbiosis theory (SET). It is now conventional wisdom that the energy-producing mitochondria in animal cells were once free-living bacteria. Indeed, they have their own genes-different from nuclear DNA. Margulis provides many examples of fruitful symbioses, including sexual union itself as the merger of sperm and egg cells. According to SET, there are successive steps or mergers that led to multicellular life forms: In steps one and two the oldest bacterial forms-the non-oxygen breathing 'archaebacteria' found in deep ocean vents-merged with swimming bacteria two billion years ago to form the nuclear heart of animal, plant, and fungal cells and provide the cilia for swimming. Later steps introduced a third partner able to breathe oxygen and added the ability to engulf and digest food (phagocytosis). The last step involved engulfing yet another bacterium-but one these various new forms of life could not digest: bright green photosynthetic bacteria. The bone of contention here is the origin of ciliated cells-critical to evolution for their vital role as sperm tails, among other things. Margulis has a theory about their origin, but as they say, more research is needed. Margulis' theory also dictates a change in taxonomy to five kingdoms: bacteria at the base, then 'protoctists' (algae, slimemolds, ciliates) next, and then animals, plants, and fungi. Finally, she defends Lovelock's Gaia theory, which she interprets to mean that enormous interacting ecosystems on Earth achieve homeostasis rather than that the planet is in the hands of some benign Mother Earth. This is vintage Margulis-personal, autobiographical, passionate, argumentative, at times over the top, but full of ideas-at least some of which, in the past, have proved to be right.

Margulis is a world class researcher and a scientist who has changed the way we think. However as a summary of her life's work this book makes her seem petty and small. She is dismissive and patronising when she discusses work tha disagrees with her own and often seems to be damning with faint praise. A perfect example is her dismissal of Woese's division of Archaea from Eubacteria. She belittles his division because to her it obscures the importance of the division between eu and pro karyotes (it certainly didn't to me) even though she grudgingly says that it's better than the plant animal dichotomy. Woese's classification is far more reflective of reality than Margulis's, and shows how even for eukaryotes we overestimate the importance of multicellularity as it divides the protozoa which just form one finger in Margulis's classification. There are much better books about symbiosis several of them written by Margulis.

Lynn Margulis takes a decidedly personal approach in explaining her view on how the two theories she has been most devoted to in her career, serial endosymbiotic theory (SET) and GAIA, the interrelation of all things, are linked.

Beginning with the smallest organisms, bacteria, all the way to the largest, the planet Earth, Margulis charts the way from the beginnings of life to current day thinking in symbiotic biology. Symbiosis, which is the biological term for the intimate and mutually rewarding pairing of two kinds of organisms, is critical to evolution. A reknowned expert in both SET and Gaia theories, Lynn Margulis writes with authority and persuasion on the subjects she knows best. Interspersed in her account is the evolution of her own professional life which allows the reader a glimpse into her mind. Called "one of the most successful synthetic thinkers in modern biology", (E.O. Wilson) Margulis invites the reader to think about the world and our place in it in a totally new way.

Lynn Margulis is Distinguished University Professor in the Department of Geosciences at the University of Massachusetts, Amherst. She is a prolific author, writing mostly about the early stages of life on Earth, particularly with regard to microbial evolution and its contribution to organelle heredity in multicellular organisms. Throughout her long career she has never ceased to challenge the views of the scientific establishment of the day, doggedly persuing every avenue of enquiry and bringing common sense thinking (invariably backed up by good, solid scientific investigation) to a number of controversial fields of study.

She is probably best known for her theory of serial endosymbiosis -- the process of successive fusion of genomes through the formation of countless, novel symbiotic consortia of microbial organisms. Since its formulation over 40 years ago, this theory has always threatened the central tenet of neo-Darwinism -- that genome alteration occurs principally through random mutation -- and getting it accepted has been a long, up-hill struggle. Lesser mortals would probably have given up trying long ago. Professor Margulis has also worked for many years on the development of a 5-kingdom taxomony which has eventually been accepted as a more appropriate replacement for the previously long established (but hopelessly inadequate) division of all living things into just plants and animals. One cornerstone of that work is the recognition of the place of microbes (bacteria and protoctists) as well as fungae as living kingdoms every bit as distinct as plants and animals, and occupying crucial places in the evolutionary scheme of things.

In addition to fighting the unfashionable microbial corner in life-sciences thinking, Lynn Margulis has also been active at the other end of the scale, contributing to the development of the Gaia concept. Originated by James Lovelock, this posits that the interactions between the Erath's bioshere, hydrosphere, lithosphere and atmosphere act as one vast self-regulating system.

In "The Symbiotic Planet: A New Look At Evolution", the author provides a summary of these areas of her life's work and explains the connecting threads that link them all. Along the way, she provides some interesting asides on both her personal scientific journey and the difficulties involved in overcoming long-established prejudices (both within and outside the scientific community). As such, this book forms a useful introduction to the work of Lynn Margulis.

In spite of its complex and specialist subject matter, the book remains eminently accessible even to the lay reader. For many, this will be a quick and light read, which, whilst uplifting and inspiring in its outlook (and potentially eye-opening in its content) may nevertheless feel to lack substance to those looking for an in-depth treatment. For that, you'll need to turn to other books, mostly by the same author. Her "Early Life: Evolution on the PreCambrian Earth" (written in conjunction with Amherst colleague, Michael Dolan) forms a useful and technically detailed account of current state of thinking on the earliest phases of microbial evolution, whilst "Acquiring Genomes: A Theory of the Origins of the Species" (co-authored with her eldest son, Dorion Sagan) provides an in-depth study of Serial Endosymbiosis Theory. Details of the five-kingdom approach to the taxonomy of living things can be found in "Diversity of Life: The Illustrated Guide to the Five Kingdoms". The definitive text regarding the Gaia Concept remains James Lovelock's "Gaia: A New Look at Life on Earth". But if all you want is a quick overview of all of these, this book will do just fine.