Liaisons of Life: From Hornworts to Hippos How the Unassuming Microbe Has Driven Evolution

Natural selection is a powerful force, but I have long suspected that other factors were involved in the evolution of life. One of these factors is the tendency for organisms to form partnerships (symbiotic relationships that may benefit both). Often this starts as parasitism, but may become (through natural selection perhaps) a mutual dependency. Wakeford has eloquently summarized the growing evidence in this area. Lichens are one notable example which were ignored by most 19th Century researchers. Indeed, as Wakeford points out the Swiss botanist Simon Schwendener and the well-known children's book writer Beatrix Potter had shown that lichens are composite organisms, consisting of both fungus and alga. Both Schwendener and Potter were ridiculed by the scientific society of the day, but were later shown to be essentially correct in their views. Since then other scientists, including Lynn Margulis, have produced solid evidence that all multicellular organisms are essentially composite organisms, containing organelles like mitochondria and chloroplasts that were once independent organisms in their own right.Together with new developments in genomic research involving the switching on and switching off of genes these ideas will certainly alter our thinking about biology. Because of this I think we will soon have a totally revolutionary view of how life originated and evolved. Not all of Darwin's ideas will survive and many if not most may be modified (as some already have been), but I think that Darwin, who was the ultimate in curious scientists, would have approved!I recommend this book as a well-written very good introduction to the idea of symbiotic evolution.

This book is about symbiosis and how prevalent it is. It is also about how politicized the concept has been historically. From the experience of nineteenth-century biologist and illustrator Beatrix Potter whose identification of lichen as symbionts went against the established dogma as filtered through the ideas of Pasteur, to "anti-communist" biology as practiced by some Western scientists who saw symbiosis as supporting the collective, it is amazing how purely political ideas successfully censored the scientific. Symbiosis has even been thought of as "feminine" and contrary to the noble interpretation of Darwinism as the survival of the fittest.But Wakeford is able (after a fashion) to go beyond the politics and demonstrate in a most convincing manner that the symbiotic way of life is vastly more important and enormously more widespread than is usually imagined. Most of us know that legumes work symbiotically with rhizobia bacteria to fix nitrogen in the soil so that it is available to the plant, but what surprised me is to learn that 90 percent of plants host mycorrhizal fungi (p. 167) and are therefore symbionts. As Wakeford asks on the same page, "Can we continue to simply call them plants without acknowledging their fungal dimension? Is a cow an animal or a microbial fermentation vessel, when without the microbes, the cow would not exist?"Good questions, and indeed, what about humans who have microbes in our guts that help us to digest our food? Are we in symbiosis with those microbes? Without the beneficial bacteria in our guts, the harmful bacteria would run rampant and we would be led to disease. Ants are not merely ants, they are farmers who harvest fungi gardens. They and the fungi are in symbiosis, living together, dependent upon one another for their survival. And what about termites, creatures who harbor microbes to digest the wood they eat? The broad, general message of this book is that cooperation between species is at least as important in evolution as is competition.Reading this made me think that perhaps the idea of competition in evolution is merely an anthropomorphic delusion. Certainly Wakeford shows that our notions about parasites and who is feeding on whom, may be in error. He writes, "Rather than discrete categories, the terms _mutualist_, _parasite_, and _pathogen_ are better seen as fuzzy points on a continuum, along the length of which an association between two organisms may fluctuate. For many associations, the point they occupy on this continuum is as difficult to assess as it is to say who gains more...in a marriage between two human partners." (p. 184)There is an old saying, that I got from somewhere years ago. It is, "Everything works toward a symbiosis." This book not only supports that idea, it even, taken further, supports the idea of Gaia, namely that all the living creatures on this planet form a single organism. I don't necessary believe this, the "strong" Gaia hypothesis, but I think th

Bacteria and fungi really get a bad rap. We generally think of them as belonging to George Bush's axis of evil. As a matter of fact, says author Tom Wakeford, the majority of these mini creatures are essential for life. This is an easy to read, highly accessible little volume on symbiosis. Symbiosis involves two or more life forms combining their efforts to add to the life benefit of each. At the beginning of the book we bump into, of all people, Beatrix Potter of Peter Rabbit fame. She was actually a biologist who subscribed to the then dissident theory that some organisms were combinations of two separate entities. She believed that lichens, those lumpy gray/green things on rocks and tree trunks, were composed of a fungus and an alga. Her scientific peers were so scornful of this belief that she ultimately quit biology, and consoled herself by writing. This career change could be considered good or bad, depending on whether you are fascinated by lichens or prefer to read books about Mrs. Tiggy-Winkle.We learn of the interesting symbiosis between plants, fungi, and bacteria. Nitrogen fixing bacteria provide the plants with necessary, accessible nitrogen. Part of the problem that plants then face is finding the rest of the nutrients that they need. They simply can't grow huge root systems to search and find patches of underground food. Various fungi solve this problem by linking up with plants. They then send tiny tendrils far afield that discover the nutrients and send them to the plant roots. Orchids in the tropics have become endangered species. People dig them up and send them to collectors in the other parts of the world. They are then planted in gardens where they promptly die. They require a certain fungus to survive, and that fungus is found only in the habitat where they originally grew.The book is full of tales of symbiotic science. How do some insects thrive on nutrients from leaves that they can neither chew nor digest? What bacteria live in our bodies, and how do they help us? This is one of those great science books that both teach and entertain.

I don't often race through a book on natural history, preferring to read a chapter or two at a time, think about them, and then read a bit more. This book is an exception; I read it in one sitting. Why? Because the author makes a well-argued case that essentially all species are strongly symbiotic with others. (Nine out of ten cells in "your" body are fellow travelers, although they account for only ten percent of "your" body mass. You couldn't survive without many of the species, nor they without you.) More importantly, evolution in one species forces -- and can be caused by -- evolution in the symbiotes. Lots of positive feedback loops here, meaning that once a tiny change occurs, it may destabilize the system enough to cause it to fall into another stable configuration. Sooner or later, it may happen that one cannot live without the other. Still later, only vestiges of one may remain. This is a more subtle way new species can emerge - and perhaps a more common one -- than simple survival of the fittest.The book also outlines the horizontal transfer of genetic information (from one living organism to another) to complement the much more widely known vertical transfer (from parent to child). This concept is not nearly as widely known as it should be in these days of genetic engineering.On the whole, the book is well written, with plenty of detail to support its conclusions. Minor stylistic problems include an occasional overdose of "gee whiz" statements and rhetorical questions. If you are looking for a pleasant way to get a really solid layman's grasp of evolution, read Darwin's Ghost, by Steve Jones, followed by this book and Wonderful Life: The Burgess Shale, by Stephen Gould. I'll bet that you'll reread all three of them. At least I have.

Suppose Darwin's theory of evolution is incomplete. Imagine that the missing link in this major scientific theory is one-thousandth of a millimetre long - a fraction of the size of a pinhead. In LIAISONS OF LIFE I explain how microbes - the collective term for bacteria, fungi and a disparate assortment of single-celled organisms called protists - have in fact been key players in the evolutionary process.I started writing LIAISONS OF LIFE because I discovered an unwritten history of evolution that had been researched by academics such as Jan Sapp, and biologists such as Lynn Margulis, but not given the kind of treatment that makes a page-turning story for non-specialists.LIAISONS OF LIFE provides a history and explanation of symbiosis, the scientific name used to describe long-term intimate associations between different organisms, usually involving microbes. It is the vital role of microbes, which were denounced by biologists long ago, that is now growing in popularity and forcing scientists to rethink the Darwinian theory of evolution.Drawing on new evidence from creatures found in underwater volcanoes, termite mounds and the gaps between our teeth, LIAISONS OF LIFE suggests that staying alive is as much about bonding with your neighbours as it is about growing and reproducing. It shows how germs blazed the trail that was later followed by plants and animals.Despite having been first proposed over a hundred years ago, the idea that liaisons with microbes were the driving force behind evolution has taken over a century to reach centre stage. I describe that, "It is no surprise that out of the three diseases virtually defeated by modern medicine - smallpox, polio, and measles - none are microbial (they are viral), whereas of the three biggest current killers - malaria, TB, and AIDS - two are." The reason for this is quite simple. Not enough research has been conducted on the microbe. Two of the microbe's biggest obstacles were its minuscule size and the manner in which it received notoriety. Instead of appreciating its contribution to cheese and wine and its insurance in the fertility of crops, the microbe was immortalised by medical research, where its presence was seen as a sure sign of disease.LIAISONS OF LIFE explores the mixture of political prejudice, technological backwardness and blind ignorance that lead the revolutionary ideas of a handful of pioneers to be condemned as heresies, only to be celebrated today as some of the greatest discoveries in the history of science. Some of the precarious fortunes of the pioneers charted in the book include Beatrix Potter, H.G. Wells, Louis Pasteur, and Lynn Margulis.I point out how three of the most important breakthroughs of the past century -- symbiogenesis theory, microbe-mediated immunity, and the Gaia hypothesis -- have all challenged traditional biological theories by uncovering the hidden powers of the microbial realm. In short, I've tried to make LIAISONS OF LIFE a page-turning stor