on December 3, 2000
This is one of those rare books that can totally alter how you look at the world. Read it and you begin seeing parasites in every skin blemish you have. See a cat catch a mouse and all you can do is think about all the parasites its about the ingest. You find youself wanting to visit the parasite museum in Maryland to see all the horrible creatures you've been reading about. You begin thinking that Zimmer's right and that parasites have driven the evolution of the world. You begin wodering if Stephen King has read it and if so what novel he's writing. You begin wondering if there's thousands of little cysts in your brain and that your life goal of going on safari in Africa may need revaluated. You imagine what its like to extract a guinea worm from your leg. You question whether or not you will ever eat crab again. You wonder whether the reason you've been so hungry of late is because there's a sixty foot long tapeworm inside your intestines. It's a stunning book and an important one. Zimmer found something obvious that's been overlooked in biology and if he's right will change the way we view life. Survival of the individual will be changed to survival of the creature living inside the indiviual. For example, there is a parasite that gets inside a snail, takes it over, forces it climb a blade of grass and wait for a grazing cow to wander by and eat it. The cow is where the parasite wants to end up. The snail is just a vessel to reach the cow. The young of the parasite end up in cow pies which the snail eats and the cycle begins again. The complex world of flukes and tapeworms, of enslaved crabs and suicidal snails, of sleeping sickness and malaria, is like a car wreck: you want to turn away but you can't, you're compelled to look fearful of what you might see. As you explore the book you learn that these creatures are much more than revolting. I can't say you'll ever view them with sympathy, you can view them with respect -- and hopefully at a safe distance.
Once considered a "degenerate" form of life, parasites are being seen as important indicators of how evolution has progressed over 4 billion years. Zimmer credits them with being the driving force for biological diversity. He substantiates this claim with a sweeping, evocative survey of what is known today about parasites. That, he regretfully concedes, is little enough. What is known is that many early conceptions about parasites needed to be thrown aside as more information about this highly adaptable and widely variable range of organisms emerges.
While we may recoil at the term "parasite", Zimmer identifies but one villain in this book. Ray Lankester, a devoted Edwardian-era evolutionist, postulated that parasites were a "regressive" form of organism. He thought they shed evolutionary advantages as they simplified their bodies through their life cycles. Lankester thus set the tone for generations - biologists avoided studying parasites as offering no additional information revealing evolution's processes. Zimmer explains that since parasites are predators, it was thought they ought to follow the patterns of other predators - stalking prey like lions, or following scent gradients like sharks.
Instead, as more about them came to light, it was revealed how adaptive parasites are. Some, in fact, have developed the talent of making "prey" come to them. One fluke invades a snail early in its career. In an intermediate, but distinctive form, it then moves to an ant. Residing in the ant's brain, at some point it directs the ant to climb a grass stalk. There it waits for the grass, along with the ant and itself, to be eaten by a cow. The fluke cruises through the cow's stomach before taking up residence in the liver as adults, yet another body form. When the eggs are produced, they return to the intestinal tract to be later deposited on the ground, awaited by the snails. Looking at each phase, residing in a different host, you would be inclined to see it as a separate species.
This note is but one of the endless chorus of parasite adaptations Zimmer relates in this excellent book. He joins the refrain of older scientists lamenting the lack of upcoming researchers needed in parasite studies. Unlike the animals we see around us, most parasites have astonishingly varied body forms as they go through the phases of their life cycles. For years, this catalog of body plans was thought to display different species. Only recently has it been demonstrated that these creatures changed shape and function dramatically as they changed living environments. Identifying each stage, the invader's function there, the impact on the host and other elements requires long, patient and dedicated work.
Those of us in the urban world think we can keep parasites at a distance, flooding our farms and wetlands with chemicals to fend them off. This is false confidence, Zimmer reminds us. Parasites are the most adaptable forms of life on the planet. They are as likely to promote change as respond to it. Zimmer cites Robin Dunbar's thesis that grooming for parasites ultimately allowed humans to develop speech and language. He explains how our immune systems and parasites enter a modus vivendi that allows the parasite and host alike to survive. Recognising how that process evolved could lead to better coexistence through "taming" the invaders.
Coexistence with these minute creatures turns out to have many implications. It's now clear that the development of agriculture made human society vulnerable to invaders unknown on the savannah. Human bodies became less robust and mortality rates rose. How far back in time have they had influences on us and what are those? Zimmer suggests that some monkeys have developed "manners" in resource or mate competition. They scream and cavort, but don't scratch or bite rivals for fear of bloodworm infection. Others use particular leaves to clear digestive tracts of infestations. We hear of researchers seeking "genes for" schizophrenia, homosexuality, even "gods". Zimmer thinks we're looking in the wrong place. Instead, he urges, we should identify the "flukes for" these and other aspects of human behaviour and form. [stephen a. haines - Ottawa, Canada]
on June 10, 2003
I was drawn to this book orignially out of the idea that things so small can cause so much damage and or alter larger animals in ways some would find hard to believe. One of the previous reviewers mentioned something about sacculina (a parasitic barnicle that attacks crabs). Reading about how sacculina castrates its host and makes it care for its young was one of the things that got me interested in reading this fascinating book. Sacculina is only one of many fascinating parasites discussed however.
Many are familiar with parasites such as cuckcoos, tape worms and trichinella but few have heard of parasites such as the lancet fluke and even fewer are familiar with its life cycle and what it does to its host. In terms of the spooky element, I think Dicrocoelium dendriticum (the lancet fluke) ranks as one of the top villains given in the book. The lancet fluke has three different hosts, namely the snail, the ant and cow or other grazers. As an adult, the lancet fluke spends its time in the gut of a cow where it lays its eggs. The eggs are then deposited on the ground with the cow's feces then snails eat the eggs which hatch in its intestines. The baby flukes bore through the snail's gut emerging from the snails slimy body and onto the ground where they attract the attention of ants. The ants eat these slime balls and become infected. The flukes then make the ants climb up the highest blade of grass they can find and lock their mandibles onto the top of the blade hanging until they are eaten by a grazer to continue its life cycle. There are a few interesting details which I intentionally left out.
Only one parasite in the book made me cringe and that was with candiru. Candiru is a thin fish found in the rivers of Latin America. Woe to the unfortunate soul who happens to urinate in a river in the presence of candiru because it will detect the odor of urine and ram itself into the victim's urethra (male or female) and lodge itself there with its teeth. Candiru is virtually impossible to remove once inside the urethra. Humans are not candiru's natural hosts however, it attacks them as a mistake.
The book also expounds on how and why parasites have a vital and critical role to play in ecology. Examples of bad things happening because certain parasites were eliminated is discussed.
on September 8, 2000
This fascinating book contains absolutely everything you never wanted to know about parasites. Zimmer reveals that these often maligned & misunderstood beings are actually highly evolved and complex creatures capable, in some instances, of controlling the sex lives and/or behavior of thier hosts. Apparently, every living (or once living) thing on the planet is full of 'em, so you might as well pick up PARASITE REX and learn what interesting things they can do. Some of the bios in this book may creep you out but you'll never look at yourself (or anything around you) the same way again. Zimmer does an excellent job explaining the ins and outs of the parasite lifestyle in a readable and enjoyable way. Recommended!
on September 2, 2008
Some other customer reviewers treat this book as if it was a horror novel by Stephen King, and both the title and the back matter certainly give that impression. "Imagine a world where the parasites control the minds of their hosts, sending them to their destruction...where parasites steer the course of evolution, where the majority of species are parasites. WELCOME TO EARTH".
In reality, Carl Zimmer's "Parasite Rex" is a perfectly serious, popular science book about parasites and their impact on evolution. Zimmer, and presumably the scientists he interviewed, believe that the majority of species are parasites, and that parasites might be the driving force of evolution. Apparently, this hasn't always been the scientific consensus. For a long time, parasites were seen as degenerate organisms, organisms that had "devolved" rather than evolved. This was connected to a misinterpretation of Darwinism as "progressive" evolution. Since parasites didn't seem "progressive", they were considered evolutionary dead ends. Sometimes, the political analogies were pretty transparent: parasites were a metaphor for human welfare cheats (and welfare states).
Today, scientists know that parasites aren't "degenerate". Quite the contrary. They are perfectly well adapted to their respective environments, and their life-cycles and behaviour are incredibly complex, which implies that they have been evolving for a very long time. "Parasite Rex" takes this reasoning one step further, arguing that co-evolution between parasites and their hosts has been a prime feature of all evolution, and that the parasites are the most dynamic part of that process. In effect, the course of evolution, perhaps even human evolution, is steered by...the parasites. They are the movers and shakers of planet Earth.
Zimmer also believes that many natural scientists haven't faced the implications of this yet. Many studies of population dynamics and animal behaviour are made without taking into consideration that parasites might affect the populations, and even their behaviour, in dramatic ways. Zimmer wants biologists to place parasitology, and parasite-host interaction, centre stage.
But the most disturbing aspect of the book is, of course, philosophical.
If evolution is a blind process steered by parasites, where on earth does that leave us?
Perhaps that's why some people think "Parasite Rex" is so scary...
on October 22, 2000
Luered by the fascinating account of guinea worms and toxoplasma mentioned in Salon's interview with Mr. Zimmer, I have picked this book - and I was not disappointed. The first half of the book focusses on myriad examples of parasitic lives - which is written so beautifully, it is worth the price of the hardcover by itself. Who would have thought a blood fluke can be such a romantic? The author also introduces the people who studies the undeservingly esoteric subjects, but the main characters in the book remains to be the parasites, which leads very interesting lives. The second half becomes more theoretical, where he discusses the ecological and evolutionary root and consequences of parasitic organisms. Because the book is written for non-biologists, he does go over some facts that are obvious to anyone who has studied biology, and I found that a little tiresome (but I understand that this is necessary for many). However, if you have read Richard Dawkin's famous book "The Selfish Gene", this book brings some fresh insight into the evolution of "replicators" and the development of sex and immune system (if you have not read it, I suggest you read that as well). All in all, it is a concise, engaging book which makes for an excellent weekend read. This book will also cram you with so many interesting stories that by the end of the read you will be dying to share the fascinating stories of parasites with your friends.
on September 6, 2005
This book is an easy-to-read guidebook about parasites intended for the scientifically curious but non-expert reader. Strengths are the use of simple metaphors to explain complex scientific concepts, and the writing style, which is clear and vivid. A related strength is the tactful handling of the disgust factor, although we do get descriptions of the unsavory behavior of parasites, there was no need to skip entire paragraphs to avoid unsettling descriptions. Some of the material is organized by trips the author made to visit working scientists, i.e., an investigator in Costa Rica who hopes to catalog all parasitic species in his region. This style makes the book seem at times like a series of magazine or newspaper articles without a central focus. This limitation was not serious, and overall, this book would be an appropriate choice to inform and invoke curiosity in students and would also provide an enjoyable way for amateur biologists or scientists working in other fields to get a synopsis of the discoveries in parasitology.
on August 18, 2004
There is a theory that our universe is merely a speck in a larger universe and that each atom within us is actually an entire universe unto itself. While I have yet to find the book that will tell me the truth about the many Milky Ways my body may harbor, I have found one that tells me about a different kind of universe my body does harbor.
The world of parasites [outside of bacteria and viruses]was always, in my mind, a relatively small one. A tapeworm here, a tarantula fighting wasp there, an amoeba or two with hostile intent. NOT 200,000 different parasitic wasps laying eggs in numerous hapless hosts destined to become little more than a buffet line. A frog was always, to me, a single hopping, croaking, ugly creature that caused warts if you picked it up. NOT a veritable hotel for parasites. The world of parasites is braoder and more interesting than I had ever dreamed. Carl Zimmer does a wonderful job of bringing that world into view.
He describes the stupendously large number of parasites, how they work, what they do to their host, how they control their host, often totally controlling, and how their host fights back [though I would have prefered a bit more detail on this last point, if only to sleep better at night].
He also does a great job of remembering that even though he may have told me that Plasmodium is the parasite that causes malaria, it can be quite helpful if he again reminds me when he brings up Plasmodium fifty pages later; thus saving me the hassle of looking back through the book to remember what horrible thing it is that Plasmodium does.
As wonderful as the book is, it does have a few small faults. Early prognositcation about man as the political parasite is, at the very least, premature. Personally,I believe in saving the moralizing for after the juicy bits. Should that actually have been of interest to the readers of this particular book, then I felt it was noticeably underdeveloped as a concept.
Carl also gets a little bit soppy at the end as he tells us how wonderful and important parasites actually are. Not that I miss his point on the role he proposes,with convincing force, that parasites assume in the overall vortex of life. He articulately elaborates on fact and theory about the role parasites play; keeping species populations in check, symbiotic functions and, most remarkably, evolution [even of intellegence and languge]. Its just that, as he pleads for us to understand what important things these wee little creatures do for us and the world around us, I can't help but recall his stories of maggots eating their host from the inside [saving the critical bits for last] or parasites causing otherwise happy fish to swim upside down on the surface of the water crying out to local predators: 'Eat me, Eat me'. I still get a bit too uneasy about the barnacle that runs roots throughout a crab's body prior to castrating it to really feel as cuddly about these insidious little mischief makers as it appears that Carl does.
What I do get is an awesome sense that there is a whole world out there that I'm missing; a very important and interesting one. I begin to wonder whether my genes are here to serve me or whether I'm little more than a convenient vessel to serve them. And if that's not eerie enough, he's got me thinking that we may not actually be at the top of the food chain; maybe not even close. Ouch!
on October 11, 2000
Gripping,fascinating,mind-boggling,frightening and the adjectives can go on till infinity.One thing's for sure,this is probably the best book i've ever read in any category.Parasite Rex has made me stop and seriously consider my role and relative importance on this planet.Parasites are definitely creatures of intelligence and savvy even by some humans'standards.The way Mr.Zimmer expounds such a subject with such ease is a major credit to his communication skills.His analogies are so on point that you can easily see yourself inside an organism and watching the action unfold like a ringside seat at a big match.If all writers could simplify very technical material like Zimmer has,who knows some of us lay people could become scholars without having to go to college.For those who scoff at the thought that creatures so tiny can determinedly invade,alter,control and manipulate from organisms to entire eco-systems i dare you to pick up a copy of'PR'and be prepared to reshape your whole outlook on life.I give'Parasite Rex'five stars only because i can't give it more.Thank you so much Mr.Zimmer!!!!
on May 7, 2001
I'm going to keep this one short and sweet. Buy this book!! PARASITE REX is a riveting look into the world of parasitology. It covers literally everything a layperson could need to know about the little critters that ride along with us through life.
The author, Carl Zimmer, starts with a history of the oft misunderstood creatures (which range from viruses to animalian life and through many life stage forms). He then moves on to explaining life cycles of parasites and how they affect their environment (sometimes by controlling their hosts right down to their sex lives); he uses specific examples to do so with incredible and often gross detail. But the "gross factor" of this book is definintely part of the reason for reading it! This book is just plain fun. Zimmer also posits some theories on how to use parasites to our advantage (among other things) which sound outlandish or impractical, but are interesting and thought provoking nonetheless. Pictures and a glossary of terms are included to add to your education in parasitology.
This is easily one of the best science books of the last year. It is thorough without being difficult to read or too academic for the layperson. As well as being an engrossing read, it also is fun, gross and creepy -- just the thing to keep you up at night and make you start to pay more attention to your world. Read this book!