Creationism, in some form, will probably be with us as long as Biblical fundamentalists continue their misguided efforts to squeeze the square peg of religion into the round hole of science. But the debate over whether evolution happened was played out over a century ago; the evolution wars today are over how evolution happened. Of course, outside of professionals in the field, no one cares a whit about how cockroaches or coelacanths evolved. The evolution wars are being fought over how one particular species evolved--Homo sapiens--and the social, political and ideological implications of the competing theories.

The evolution wars began in 1859 with the publication of Charles Darwin's Origin of Species. But they heated up in 1975 with the release of entomologist E.O. Wilson's Sociobiology and have not let up since, as evidenced by the controversies generated by sociobiology's doppelganger--evolutionary psychology--and its attempt to account for human behavior in terms of evolutionary adaptations (for example, the recent attempt to explain rape as an adaptive strategy by males who could not pass on their genes by non-forceful sex). [See E.O. Wilson's "Writing Life" on pages 6-7.] The modern evolution wars now have their chronicler in sociologist Ullica Segerstrale, whose masterfully comprehensive Defenders of the Truth was 25 years in the making.

At stake in this battle are nothing less than how human societies should be structured, the nature of human nature and, as Segerstrale notes, "the soul of science." How an academic textbook by an entomologist could result in one of the most rancorous debates in all of science is marvelously explained in intricate detail, beginning with the reactions to Wilson by his Harvard colleagues Stephen Jay Gould and Richard Lewontin. Their Sociobiology Study Group, along with the politically charged Science for the People--a group of Harvard-based academics, such as Gould and Lewontin, for the diffusion of scientific knowledge to the general population--set the stage for a now-famous incident at the 1978 meeting of the American Association for the Advancement of Science: Demonstrators chanted "Racist Wilson, you can't hide, we charge you with genocide!", followed by someone pouring a jug of ice-water over his head and shouting "Wilson, you are all wet!"

Why, Wilson wondered two decades later in his autobiographical book Naturalist, didn't Gould and Lewontin just come up to his office from theirs one floor below in the same Harvard building to discuss their concerns? Why attack him in the very public pages of the New York Review of Books when this all could have been handled in private? The reason, as Segerstrale so brilliantly shows, is that science is not the private and always rational enterprise it is often made out to be. Why, Gould and Lewontin could just as easily have asked, didn't Wilson come down one floor to their offices to discuss with them in private his ideas about applying principles of animal behavior to human societies?

The answer is the same: If you want to get your theories out into the marketplace of ideas, you cannot sequester them in your office. You've got to make them public, and the more public the better. Hashing the debate out in public gives you the forum you would never get in private.

As Segerstrale argues, correctly I think, this is exactly what happened in the sociobiology debate. Gould and Lewontin had a scientific agenda that they wanted to air publicly--that adaptationist, gene-centered arguments in evolutionary theory can be carried too far, and that much in the history of life can be explained by nonadaptive processes and a multi-leveled analysis of genes, individuals and groups. What better way to do it than to use Wilson as their foil?

But who in the general public knows or cares about adaptations, exaptations, spandrels, contingencies and other esoterica of evolutionary biology? What the public does understand quite well is Nazis, eugenics, race-purification programs and other abuses of biology from the past century. Thus, sociobiology's critics reasoned, the best strategy is to begin with its ideological implications--particularly the racist overtones of genetic determinism--to capture an audience, then segue into the scientific arguments about the problems with hyperadaptationism. Gould said as much at a 1984 Harvard meeting that Segerstrale attended: "We opened up the debate by taking a strong position. We took a definitive stand in order to open up the debate to scientific criticism. Until there is some legitimacy for expressing contrary opinions, scientists will shut up." From this (and numerous interviews with all parties involved) Segerstrale concludes: "What I take Gould to be saying here is that the controversy around Wilson's Sociobiology was, in fact, a vehicle for the real scientific controversy about adaptation! Far, then, from 'dragging politics into it,' or being 'dishonest' as [Ernst] Mayr accused Gould and Lewontin of being, their political involvement would have been instead a deliberate maneuver to gain a later hearing for their fundamentally scientific argument about adaptation. What Gould seems to have been saying here is that the scientific controversy about adaptation could not have been started without the political controversy about sociobiology."

Before we accuse Gould and Lewontin of being overly Machiavellian in their political machinations, however, Segerstrale points out that Wilson was not an innocent victim in this debate. It seems unlikely that a Harvard professor could write a book whose title defines a new science of applying biology to human social behavior, in the middle of a decade that was defined by its ideological emphasis on egalitarian politics and cultural determinism, and not expect trouble. In fact, the central point of Segerstrale's book is that all scientists have an agenda and the sooner we recognize that fact and come clean with our own, the better will the public be able to judge scientific theories.

Certainly Gould and Lewontin went too far, as all social movements are wont to do. When I first met Ed Wilson, I couldn't believe what a kind, generous and soft-spoken man he is--anything but what I had expected from following the sociobiology debates. Then again, as Segerstrale convincingly shows, it would appear that Wilson knew exactly what he was doing all along. From Sociobiology to his latest book, Consilience, he has brilliantly orchestrated a program of biologizing all of human behavior, from mate selection and maternal love to war and religion. No wonder the evolution wars have been so heated. Much is on the line, and if you don't mind weeding through the sometimes overly detailed recounting of events and lengthy quotes (professionals in the field will relish every word, however), Defenders of the Truth will put you right in the heart of this epic tale that continues unfolding before us, exactly three-quarters of a century after the rediscovery of Gregor Mendel's revolutionary research on heredity.

If there is an individual besides Darwin at the beginning and Wilson now whom we can identify as the figurehead of the evolution wars, it is Gregor Mendel, whose work was rediscovered nearly simultaneously in 1900 by Hugo De Vries, Karl Correns and Erich von Tschermak. And, like Darwin and Wilson, by temperament Mendel was about as unlikely a revolutionary as one can imagine. He truly was the "monk in the garden," as his biographer, science writer Robin Marantz Henig, describes him in the title of her engaging book. We have libraries filled with works by and about Darwin, but we have almost nothing on Mendel, thus opening the door to science myth-making at its best, as Henig explains:

"To some extent, Mendel's story is primarily the story of a gardener, patiently tending his plants, collecting them, counting them, working out his ratios, and calmly, clearly explaining an amazing finding--then waiting for someone to understand what he was talking about. It is the story of a gentle revolutionary who was born a generation too soon."

Henig has done a remarkable job of fleshing out the myth with what few facts there are, and as such that part of her book is a loving tribute to a man we will sadly probably never know much about, either as a person or a scientist. Thus, the question some have raised as to the possibility of Mendel's fudging his data to make his famous 3:1 ratio come out clean is most likely an unanswerable one, because all we have to go on is a couple of letters written to a German botanist and a single 44-page paper that Mendel called a mere summary of his public lectures, written for clarity, not historical accuracy.

Therefore the action really begins in the second half of the book, long after Mendel has died, when the evolution wars start heating up again over whether traits are inherited in discrete units or whether they blend with other traits into a new amalgam. Just as Gould and Lewontin were to use Wilson to promote their own vision of nature (while both sides claimed Darwin as their hero), so too did the two major characters in the Mendel story, William Bateson and Hugo de Vries, use each other.

The parallels are eerie. Just as Wilson coined "sociobiology" and Niles Eldredge and Gould "punctuated equilibrium," Bateson created "zygote," "homozygote" and in 1905 "genetics" (from the Greek genetikos, meaning "origin" or "fertile"). De Vries shortened Darwin's "pangenesis" to "pangen," but in 1909 the Dutch plant physiologist Wilhelm Johannsen bettered him with "gene," a concept he naively presupposed to be "free from any hypotheses." Why the fight over terminology? Because language matters, as Henig notes: "This universal language was the first step in turning the emerging science of genetics into a coherent discipline."

It is here that Mendel once again enters the picture. "Every new science needs a hero--someone on whose giant shoulders his disciples can stand--and Mendel was an easy man to lionize." And just as today's debaters each believe they are "defenders of the truth," Henig shows how even when the wars began a century ago, "Both sides were playing for the highest stakes: the right to claim a truthful insight into the workings of the natural world. What they uncovered eventually became the foundation of a science that has taken us to the very brink of human possibilities."

What the future holds for the evolution wars may be glimpsed in the next generation's writings, an intriguing representative sample of which can be found in paleoanthropologist Jeffrey McKee's The Riddled Chain. The subtitle alone, "Chance, Coincidence, and Chaos in Human Evolution," tells us that this is not a strictly gene-focused, adaptationist analysis. The alliterative reference is to influences outside the traditional forces of study that have shaped the course of evolution, and once again the topic is our favorite species.

McKee cleverly draws the reader into theoretical debates about human evolution through personal stories of his field work in South Africa. But he is not just interested in the search for our origin, which is now reasonably well fleshed out in a very bushy tree of life. There is no linear chain in "the ascent of man" that can be cleanly drawn from Lucy to us. Instead, as McKee demonstrates through a convergence of evidence ranging from fossils to computer simulations, "Natural selection is severely limited both in its power to promote useful genes and in its freedom to tinker with morphology. Human bodies are not particularly well adapted in many respects, revealing the chance origins of nature's 'designs.' Chance and chaos, as much as the ever vigilant selective process, made us what we are."

To strict adaptationists like Richard Dawkins and E.O. Wilson, these are fighting words. If natural selection is not the be all and end all of evolution, then what is? Autocatalysis, McKee argues in the book's most daring chapter. "Autocatalytic evolution simply means this: evolution is caused (catalyzed) by itself (auto). It is self-propelled by feedback loops. If this means that most evolutionary change is catalyzed or caused by the inherent nature of a species, then the grand theories of environmental forcing fall away. Evolution would proceed with or without changes in climate or in the plant and animal community with which a species interacts. Evolution is the cause of evolution, and it continues by its chaotic devices."

Autocatalysis is a superior model for explaining the complexities of life because, as biologists have discovered in recent decades (particularly with the rise of the science of ecology), simple linear models fail to account for complex biological systems. The same has to be true for the history of life. It certainly is in human cultural history, which is riddled with autocatalytic feedback loops and, in fact, forms the core of Jared Diamond's revolutionary book Guns, Germs, and Steel. McKee believes that he's on to something here that could very well start yet another evolution war: "The theory of autocatalytic evolution is painfully simple, horribly mundane, and probably correct." Is it? The evidence is good, but it is too soon to tell, so as in the debate over Wilson's sociobiology and Mendel's genetics, the battle for science will be determined in both the private and public spheres of influence.

Michael Shermer is the publisher of Skeptic magazine (www.skeptic.com) and the author of "Why People Believe Weird Things." His latest book is "How We Believe: The Search for God in an Age of Science."