The Making of the Fittest: DNA and the Ultimate Forensic Record of Evolution

DNA is the genetic material that defines us as individuals. Over the last two decades, it has emerged as a powerful tool for solving crimes and determining guilt and innocence. But, very recently, an important new aspect of DNA has been revealed--it contains a detailed record of evolution. That is, DNA is a living chronicle of how the marvelous creatures that inhabit our planet have adapted to its many environments, from the freezing waters of the Antarctic to the lush canopy of the rain forest.

In the pages of this highly readable narrative, Sean Carroll guides the general reader on a tour of the massive DNA record of three billion years of evolution to see how the fittest are made. And what a eye-opening tour it is--one featuring immortal genes, fossil genes, and genes that bear the scars of past battles with horrible diseases. This book clinches the case for evolution, beyond any reasonable doubt.

"Picking up where scientists like Richard Dawkins have left off, Carroll, a professor of genetics at the University of Wisconsin — Madison (Endless Forms Most Beautiful: The New Science of Evo-Devo), has written a fast-paced look at how DNA demonstrates the evolutionary process. Natural selection eliminates harmful changes and embraces beneficial ones, and each change leaves its signature on a species' DNA codes. For example, the Antarctic ice fish today has no red blood cells; yet a fossilized gene for hemoglobin remains in its DNA, showing that the fish has adapted over 55 million years by losing the red blood cells that thicken blood and make it harder to pump in extreme cold. The fish has developed other features that allow it to absorb and circulate blood without hemoglobin. . Carroll points out that by examining the DNA of these ice fish species, it's possible to map its origins as well as the history of the South Atlantic's geology. He also uses dolphins, colobus monkeys and microbes to demonstrate how deeply evolution is etched in DNA. While searches for the genetic basis for evolution are hardly new, Carroll offers some provocative and convincing evidence. 7 pages of color illus.; 50 b&w illus. (Oct.) " Publishers Weekly (Copyright Reed Business Information, Inc.)

"Anyone sitting down to write about evolution immediately faces a big problem: too much material. Evolution encompasses 4 billion years of history on a worldwide stage. Do you take the Russian novel approach and try to cover everything? Or do you write short stories and hope they cohere?

University of Wisconsin biologist Sean Carroll chooses the latter option in 'The Making of the Fittest.'... Washington Post Book Review (read the entire Washington Post review) He dwells on critical periods in life's long saga: the evolution of complex cells in ancient oceans, of the eye in a microscopically small worm, of color vision in Old World monkeys and African apes (most animals cannot distinguish between red and green), of light skin in humans. He spends time with each story; he wants his readers to appreciate the details of how evolution works. Yet he still conveys the grandeur of the broader enterprise.

Carroll makes good use of a common thread that ties his stories together. Individuals, species and entire groups of organisms may come and go, but the molecule known as DNA never dies. It lies coiled within cells, orchestrating the production of proteins and simultaneously acting as a repository for the stored-up experience of the ages. When a cell divides, DNA arranges for itself to be copied, but the copying process isn't perfect. In this way, DNA generates evolutionary experiments. Most of these experiments are failures. But some succeed, and the success stories have ensured the survival — indeed, the exuberant proliferation — of life on this planet.

Carroll focuses on DNA's role as archivist rather than engineer. By comparing DNA sequences across organisms, biologists can reconstruct the changes that DNA has undergone from one generation to the next or over millions of years. Carroll uses DNA forensics as an analogy. Just as a jury can match DNA taken from a crime scene to DNA from a suspect, scientists can compare strings of DNA to identify the origins of species and the relationships among organisms. This body of evidence 'clinches the case for biological evolution as the basis for life's diversity, beyond any reasonable doubt,' he writes.

Carroll is an adept and wide-ranging writer. His narrative hopscotches from the Antarctic Ocean to Yellowstone National Park to the Great Barrier Reef of Australia to the Costa Rican rain forest. Even when he tells a well-known story in evolutionary biology, such as the linking of sickle cell anemia to malaria, Carroll finds a new way to tell it. One chapter begins, 'It is rumored that the most common last words humans utter are, "Hey, hold my beer and watch this!"' Reading 'The Making of the Fittest' is like spending a few hours with an extremely knowledgeable and enthusiastic dinner companion.

Carroll doesn't gloss over the details. For example, he relies on some elementary mathematics to explain the counterintuitive aspects of evolution, such as the rapid spread of advantageous mutations through populations. Readers have to learn some molecular biology — but, honestly, this is stuff we all studied in high school. How a bill becomes law is much more complicated than the basic functioning of DNA.

In a previous book, 'Endless Forms Most Beautiful,' Carroll was content to stick largely with the science. Here he has a broader agenda. 'In the court of public opinion,' he points out, 'some 50 percent or more of the U.S. population still doubts or outright denies the reality of biological evolution.' One way to interpret these poll results is simply to note how adept people are at holding two contradictory ideas in their minds — in this case, the universality of evolution and the exceptionalism of humans. The occurrence of evolution is not seriously in doubt within the scientific community. As the comedian Lewis Black points out, 'We have the fossils. We win.'

But Carroll makes a compelling case that opposition to evolution can do real harm. He describes several historical episodes where disbelief of scientific facts led to widespread human suffering: when 19th-century physicians doubted that washing their hands could prevent 'childbed fever' among the women whose children they delivered; or when Soviet biologist Trofim Lysenko refused to accept modern genetics, which contributed to the deaths by famine of millions in the Soviet Union and China.

Willful ignorance of evolution could have similar consequences, Carroll warns. It could slow the advance of biomedical understanding, condemning those with curable diseases to continued illness or death. It could also obscure the threat that human actions pose to our stewardship of Earth's resources. On that latter point, Carroll is particularly ardent. 'The future of nature at present looks terribly gloomy, much as the state of geopolitics looked to Churchill in 1935,' he writes. 'Then, as now, most of the West's leaders were in denial, guided by wishful thinking and blind optimism. ... The war on Nature has been waged with increasing intensity over the past fifty years, but few powerful allies have come to her aid.'

It's a depressing note on which to end a generally upbeat book. But maybe Carroll's despair is understandable. It must be very painful for someone who understands evolution as well as he does to watch its lessons being ignored." Reviewed by Steve Olson, who is the author of "Countdown: The Race for Beautiful Solutions at the International Mathematical Olympiad", Washington Post Book World (Copyright 2006 Washington Post Book World Service/Washington Post Writers Group)
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Introducing the lay reader to the power of DNA, Carroll (investigator, Howard Hughes Medical Institute and genetics, U. of Wisconsin-Madison) explains DNA as a living chronicle of evolution. Through anecdotes, pictures, charts and tables, he describes how evolution works, why it matters and how it has shaped life on earth. He makes Darwin's case comprehensively and in clear, straightforward prose. Annotation ©2007 Book News, Inc., Portland, OR (booknews.com)

DNA evidence not only solves crimes--in Sean Carroll's hands it will now end the Evolution Wars.

Sean B. Carroll is professor of genetics at the University of Wisconsin–Madison and investigator at the Howard Hughes Medical Institute. His first book, Endless Forms Most Beautiful, was a finalist for the 2005 Los Angeles Times Book Prize. Carroll’s seminal scientific work has been featured in Time and The New Yorker. He lives in Madison, Wisconsin.