Evolution: A seven-part, 8-hour series, coproduced by WGBH in Boston and Clear Blue Sky Productions. For sale through the PBS Web site ($99.95 for the complete series in VHS or DVD; see www.pbs.org/wgbh/evolution/shop/index.html); teachers may videotape segments for limited classroom use.
Evolution is a series for believers—believers in evolution, that is. The series assumes the reality of evolution; its goal is to explore the evolution of life on earth, not to convince viewers that evolution is real or to debate evolution and creationism (although the last program does examine challenges to teaching evolution). The series also assumes a scientifically literate viewer, what has euphemistically been labeled “the typical PBS audience.” Often, genetic and genomic terms and concepts—which may seem familiar to us but still confuse many in my parents' generation—are presented with no explanations or definitions, and geologic time periods and taxonomic groupings are introduced without explanation of their context or relationships with others. Such presentation would lend itself extremely well to constructivist teaching in the hands of a well-prepared teacher, but the lack of background information and reinforcing material may frustrate or confuse the average viewer.
Beautifully produced, Evolution offers both excellent story telling and amazing graphics and animations. From the opening credits, the visual presentation of Evolution is stunning. Especially in “Great Transformations,” the visual depictions of ancient species and environments and the evolutionary transitions among them rival the best of the big-budget animated features.
Interestingly, the narrative style varies among the several segments of the series. I found the first two the most compelling, but that may be because of the story as much as the story telling. In the first segment, “Darwin's Dangerous Idea,” dramatic re-creations mingle with analyses from modern scientists, who chronicle Darwin's development of the theory of evolution by natural selection from his days on the Beagle through the publication of The Origin of Species. “Great Transformations,” the second segment, has a most engaging plot development, beginning with the specific, relatively recent evolution of whales and moving backward to the evolution of land animals, then back to the origin of modern animal forms during the Cambrian explosion.
The common storytelling employed in most of the other segments in the series humanizes science by integrating the stories of scientists with the science they study. The series also holds the viewer's interest by focusing on human evolutionary stories, although these tales, of course, link us intimately with other species on the planet, presenting a good mix of evolutionary diversity. Examples include a primary focus on human disease and our interactions with bacteria in “The Evolutionary Arms Race”; and most of “The Mind's Big Bang” centers on the development of the human brain and especially the language, tools, and culture it engenders. The humancentric theme also emphasizes our relationship with the environment and how we change it. For a series that purports to cover 3 billion years or so of evolution, a remarkable portion of the program is devoted to just the last 100 to 1000 years. Whether in driving development of milder disease-causing bacteria or questioning the rate at which our habitat destruction has spurred extinctions, we humans clearly stand in the center of this evolutionary universe. And we are often painted as evildoers. In segment three, “Extinction!” a scientist notes that he studies extinction “basically because I am just tired of watching animals die.” While this may be a noble and sympathetic sentiment, it may not reflect a fair assessment of the natural world where, as the series well documents, species have been dying for billions of years.
Viewers familiar with the broad landscape of evolution might be frustrated by this focus on humans. One wishes that the intrinsic beauty of the many fascinating tales to be told across the panoramic expanse of species could attract viewers. But viewers have to be met on their turf, and Evolution does an excellent job of that. And this may explain why many biologists may find the series falling short. There just is not enough time to cover all of what we would like to cover, whether it is the chronology of Darwin's life or the mechanisms of speciation.
For me, the biggest frustration is the series' focus on the “what” of evolution as opposed to the “how.” My frustration is that there is so little emphasis on mechanism. How does evolution occur? What drives speciation? How do genes work to get from egg to organism and back, allowing for change? Both micro- and macroevolution suffer from insufficient attention to process. The series uses descriptive rather than mechanistic terms to discuss development of antibiotic resistance; human movement from trees to upright walking, tool use, and language; and the great Cambrian explosion. We do not get nearly as much information on genetics as I would like. Both because of my inherent interests and because of the crises facing evolutionary teaching these days, a greater emphasis on how evolution can and does take place would have been very helpful.
The series can provide some excellent models for how science progresses. The very day I viewed the segment “Great Transformations,” wherein P. D. Gin gerich firmly stated that whales evolved from wolf-like carnivores, he and several colleagues published a paper in Science (293: 2239) showing that, in fact, whales evolved from ancestral artiodactyls. Such lovely stories of the evolution of the science can teach us much about the nature of the science—in the right hands.
Also, much of Evolution's focus is on micro-, not macro-, evolution. After the second show, there is little talk of speciation or mechanisms of speciation. For example, in “Why Sex?” we are presented with wonderful stories and explanations of sexual selection from peacock tails to human dating (amply illustrated with many clips from classic movies), but we are not given any further explanation of how this sexual selection can lead to new species. Similarly, “The Evolutionary Arms Race” (segment four) spins wonderful tales of escalating toxin production in newts to counter snake predation and development of a balance between feline immunodeficiency virus and wildcat species, yet it does not explore how any of these pressures can promote speciation.
Why am I concerned about speciation and macroevolution? Because of the final segment in the series, “What about God?” This hour is the only one, beyond a brief introduction to Ken Miller in “Darwin's Dangerous Idea,” that discusses creationism and the challenges to teaching evolution in our schools. This is also the segment that I found most troubling, troubling not because of what it presents but because of what it does not present. The entire focus of this segment is on “young earth” creationists, who adhere to a strict interpretation of the first chapters of Genesis and believe that the world is of recent vintage and that God controls all events. This belief in a “young earth,” and efforts to promote it, is illustrated by three stories: Ken Ham and Answers in Genesis (a Kentucky-based organization founded by Ham to promote creationism); the attempt to balance religious and scientific teaching at conservative, Christian Wheaton College; and the efforts of students in Lafayette, Indiana, to introduce special creation into their biology curriculum. I admit to the bias of a sore loser—I have been trying for years to get on Ken Ham's Top Ten List of Most (Least?) Wanted Opponents of Creationism, but I haven't made it yet. But the real problem is not the relatively small, though vocal, group of fundamentalist young earth creationists.
The real challenge to teaching evolution today comes from members of the “intelligent design” community, who argue that their brand of creationism is really “creation science” and who have been fighting to get this very, very bad understanding of science into the curriculum. Unfortunately, as we have seen recently in Kansas and even in the US Congress, they represent a much larger, more politically savvy group—and they have been enjoying too much success in their efforts.
In sum, then, Evolution is an elegant and engaging, important contribution to our educational efforts to promote public understanding of where we come from and how we are connected to the larger biosphere. There is indeed, as Darwin said, “a grandeur in this view of life.” If it falls short, it is because we simply cannot cover 3 billion years of evolution in 8 hours and get in all the details. One might describe Evolution in the terms of a recent commercial for light beer: While some of us may find it less filling than we would like, as public science education, it certainly tastes great.