Microcosm: E. coli and the New Science of Life
Author: Carl Zimmer
Publisher: Pantheon Books
Available: Order Here
In newspapers or science programs, one occasionally hears mention of an evolutionary ‘ladder,’ naturally with humans perched on the exalted top rung. Not to take anything away from our species, we are indeed uniquely endowed by physiology in numerous ways. But until I read Carl Zimmer’s Microcosm, I didn’t fully appreciate that that picture isn’t just over simplified, it’s just plain wrong.
The anatomically modern human species has been around a few thousand generations. Our class, the mammals, has been evolving for many millions more leaving behind an impressive legacy of living form and function. Imagine what our bodies, organs, and cells might be physically capable of, if the long sharp scalpel of natural selection had been operating on our kind for uncounted trillions of generations. There are such miraculous creatures.
One in particular has developed the capacity to completely remake their entire metabolism from the molecular bottom up or retrofit their gross anatomy from the top down. If humans were capable of equivalent transformations, we would be able to sprint across a continent subsisting only on a diet of rancid meat, stand on the ocean’s shore, sprout a tail and gills in the space of a few hours, and swim across the Atlantic feeding only on toxic red algae. Yet even that doesn’t do their sophistication justice, for they have evolved to evolve with clever system built into and onto clever systems. They are among the greatest human allies; they can be our worst enemy. More recently, these marvelous creatures have become a biological Rosetta Stone translating nature’s most tightly held secrets of life, and they’ve been domesticated to serve man.
Carl Zimmer tells all those tales and many more quite masterfully in Microcosm.
Had another author told me his publisher was sending me a copy of a book on Escherichia coli, I would have been perhaps quietly unenthusiastic. But best selling science writer Carl Zimmer is a master story teller and superb researcher. He’s also renowned for effortlessly slipping a giant payload of scientific knowledge into the reader, sweetened with human drama, one so comprehensive a student struggling with a dry textbook would have had to hammer into their head over the course of an entire semester.
Carl didn’t disappoint: within a few short pages he had me completely, delightfully hooked. Not until I sat down to write this review did it really hit me just how packed this book is with science, each chapter written so well it can stand alone as a specific object lesson, and each lesson coming together in the book with biology, historical characters, and eureka moments in a scrumptious blend of mind candy.
I asked the author why E. coli?
I realized a couple years ago that there was a lot of research coming out that was plumbing the depths of life itself--what it means to be alive--with a clarity we've never had before. And then I realized that a lot of that research--if not most--used E. coli. So why was E. coli, this humble little gut germ, our guide to the mysteries of life? Because, I recalled, scientists were able to use it in the mid-1900s to create the science of molecular biology, figure out how genes work, and win a bunch of Nobel Prizes. And the book just crystallized right there for me. -- Carl Zimmer
If you’ve heard of E. coli, it’s probably because of an urgent health warning broadcast on your local news. They were first identified by Theodor Escherich in a residue we needn’t dwell on. Since that time they have become the most studied microbe in the annals of science. That story encompasses every aspect of the human drama, disease, tragedy, suffering, and death. But the scientific dividends have now led to lives and limbs saved by the millions, and billion dollar fortunes made.
It’s that journey of discovery that Microcosm takes the reader on, and I’m glad to say it’s filled with useful gems of molecular biology explained with such elegance that even the newly minted wonder junkies can come along for the ride.
Let’s say for example a bacterium needed to be able to digest a substance that came and went in the microenvironment. How to turn that ability on or off, on demand, with no brain, no nerves, lacking even the five basic sense? If E. coli needs to be able to digest a substance X which varies randomly in quantity, it simply makes the molecules used to break down X, let’s call it BX, into the same building blocks it breaks everything down to, and then hands the reduced materials off to the processes which sustain and maintain the organism.
But it wouldn’t do to have too much BX floating around when unneeded, getting in the way of other reactions and holding molecular resources hostage. So E. coli makes an anti BX, another substance which breaks BX back down. But anti BX is destroyed by X itself, so when X is present, anti BX is eliminated, meaning BX builds up to the point it can digest X in enough quantities to serve the needs of the organism. When the supply of X dwindles, the reverse occurs. Simple, elegant, and effective -- although my clumsy rendition above does both the author’s explanatory talent and the science of microbiology great injustice.
In this book we learn at the level usually reserved only for microbiologists that the term species is strained, pun intended, when discussing microbes like E. coli: There are types of E. coli as different from one another as chalk and cheese.
Two strains, K-12 and O157:H7, are enough to provide a sense of how diverse E. coli is a species. K-12 is so harmless that scientists make no effort to protect themselves from it. If K-12 is a lapdog, O157:H7 is a wolf. It injects molecules into our cells, disrupts our intestines, makes us bleed, loads us with toxins, shuts down our organs, and sometimes kills us. -- Microcosm, Open Source
Throughout the book, Zimmer throws in scientific three-point zingers couched in almost prosaic form that have come to be one of his trademarks. He notes for example that E. coli are so numerous in the gut of most people, that if you added up all the genes contained in your body, most of them would be non-human. Or the use of palimpsest analogy when explaining the genetic traces researcher find in extant microbes when examining them in hugely magnified detail. The latter of course is one line of evidence which powerfully supports common descent and the greater science of evolutionary biology. Indeed, readers who follow the twists and turns offered by proponents of Intelligent Design will love observing Zimmer unwrap Darwin's Black Box to reveal the exquisite, natural machinery inside, and most especially the section of the book detailing the microbiology and legal misuse of the bacteria's flagella.
At the Dover trial, [Dr. Michael] Behe had a textbook illustration of E. coli’s flagellum projected on the courtroom screen, and he proceeded to marvel at it all over again. "We could probably call this the bacterial Flagellum Trial," a lawyer for the school board said. -- Microcosm, Palimpsest
Even hard nosed capitalists will admire the ingenuity of Dr Herbert Boyer. As Zimmer explains in detail, Boyer learned to engineer E. coli to make human insulin and created a brand new industry, biotechnology. The company he and a partner created for $500.00 each was named Genetic Engineering Technology. Today, those small investments would be worth billions in Genentech shares traded on the New York Stock Exchange under the appropriately chosen ticker symbol, DNA. I was so blown away by this part of the book that I researched and wrote a science essay on Boyer and his work, one that was immediately snapped up by a publisher for a sweet price.
For those of you who would like to fill in some gaps in molecular biology, and for the veteran science aficionado who might take pleasure in learning of the history and the biology of the best studied microorganism on earth, this book is for you. It is aptly named for the fascinating worlds within worlds found within a droplet of water or a tiny crumb of ground meat and populated by creatures as diverse and dazzling as those found in a Carboniferous rain forest. If you liked Isaac Asimov’s written version of Fantastic Voyage, but prefer your adventures wrought in documented science using real discoveries and the names of actual explorers, I highly recommend Zimmer’s Microcosm. May you find it as enjoyable and profitable as I did!