Product Description

Addressed to general readers, this text provides a view of evolution as a process based on interdependancy and the interconnectedness of all life on the planet. It brings together discoveries in microbiolgy since the mid-1970s with the research of the author to create a picture of the world that is relevant to our understanding of the future of our planet.

Product Details

• Amazon Sales Rank: #470607 in Books
• Published on: 1997-06-11
• Original language: English
• Number of items: 1
• Binding: Paperback
• 304 pages

Customer Reviews

Needs updating
This was originally published in 1986, and is in serious need of an update. For example, it quotes the long held, but totally incorrect, belief that if the oxygen content of the atmosphere was raised just a couple of percent, then many living things would spontaneously combust. We now know that in fact the oxygen levels around 300 million years ago were as high as 35% with thick, non-spontaneously-combusting forests. As a second example, it makes fallacious remarks that humans are the only primates that eat meat, which anyone who has seen any David Attenborough documentaries involving chimps or baboons will know is totally false. The latter example occurs in a chapter on human development which is rather out of place in a book about microbial evolution, and gives the feeling of being there purely for padding.

Whilst this book serves a useful purpose in "stating the case" for microbes against the egocentric attitudes of mankind as being the pinnacle of evolution, there are better overall and more up to date works on microbial evolution for the general reader.

Don't miss the beginning . . .
Margulis and Sagan return us to the days of life's inception. It's a journey in time and scope, travelling far back and down in size. Looking at the microbial world might seem unrewarding, but they escort us through a rich trove of information. The knowledge contributes to our understanding of how we work. Although mysteries remain hidden in that distant time, the authors clearly demonstrate the logic of how early life has developed into ourselves and our animal and plant neighbours on this planet. The title suggests that the journey must necessarily occur at high speed, but they demonstrate that if we don't appreciate the beginning the remainder of the trip will be undertaken in obscurity. A better knowledge of the origins, they suggest, will also give us better insight into what the future heralds.

After some preliminary discussion of how life started, the authors move into the realm of cellular organisms. The various ideas of life's origins are fascinating, but not until it achieved the level of individual micro-organisms does life take on meaning. The authors describe the events occurring during the long reign of the prokaryotes. These simple organisms were little more than a bag containing some genetic information. Yet, their emergence was the start of true life. While it's easy to think this "primitive" organism has faded into oblivion with the passage of time, the authors remind us that all our bacterial neighbours [and some inhabiting us!] are of that distant family.

When conditions varied in certain localities, these simple creatures performed some amazing tricks. One of these resulted in a devastating event the authors term The Oxygen Holocaust. The original prokaryotes thrived on hydrogen, making useful compounds of it and other elements. Since the best available source was water, the resultant waste product was oxygen. As this pollutant entered the atmosphere many organisms were forced to change their lifestyle or die out. The massive changes resulting increased the complexity of many organisms that began adding new protective devices to their structures. According to the authors, some cells had already initiated a new survival technique - the merging of various prokaryotic cells resulting in a new type. The new cell packaged its genetic material in a nucleus, creating the form known as the eukaryotes. Eukaryotic cell structure led down the long evolutionary track to complex creatures like ourselves.

There is a goal behind their descriptions of life's evolution. They remind us that textbook illustrations of individual bacteria are misleading. All Bacteria "clump" in some form or another as part of their survival strategy. Because these tiny organisms encounter so many environments and because their genetic makeup allows astonishing variation, many bacteria form communities with various groups performing specific tasks. These roles may include shielding the rest of the community from environmental hazards, processing food and waste or mobility. This revelation also points up a major theme of this book - cooperation has played a greater role in evolution than has competition. Cooperation is a survival strategy whereas competition may leave too few winners to ensure perpetuation of the species. How far can the cooperation extend in a planet of highly varying environments?

That question is answered in their concluding chapter. In it, they extend their previous narrative to reinforce the case for James Lovelock's Gaia thesis. In their view, Gaia is a "superorganism" extending throughout the entire biosphere. It is self correcting and self-regulating - indeed, the role of evolution is but the "operating system" of this global organism. Since the oxygen we breathe came from waste-expelling microbes, more than lifeforms are contained within Gaia. The atmosphere and oceans aren't habitats and support systems for life, but an integral part of a grander structure, one thoroughly integrated. One can only wonder what Darwin might have thought of this extrapolation of his idea of evolution by natural selection. This is not the place to debate Lovelock's thesis. While Gaia has been strenuously challenged by other commentators, Margulis and Sagan weave a tightly knit support for the idea. They do it earnestly and with clarity, and their view should be given some consideration. Strangely, however, while they have no qualms about describing certain theories about life's evolutionary progress as "still a mystery" or "controversial," this aspect of the book is presented as a given. The inconsistency is glaring, but shouldn't detract from the worth of the book as a whole. [stephen a. haines - Ottawa, Canada]

Easy to read, nice to follow
This is a great book to understand. IT's not like a textbook where you have to look up the words in the glossary and try to understand what it's trying to say.