Last night, Carl Zimmer, a popular science writer who has published work in the New York Times and is the author of several books, including the upcoming “Smithsonian Intimate Guide to Human Origins,” spoke to a packed audience of students and faculty in the Scheuer Room. His lecture, titled “Discovering Your Inner Chimp: Human Origins in a Controversial Age,” described current scientific thinking regarding human evolution, and addressed the current controversy over the teaching of evolution in schools.
Zimmer began by summarizing the history of the evolution debate, beginning with the infamous Scopes Trial of 1925, in which a high school teacher was convicted of breaking a Tennessee law that forbade the teaching of Darwin’s theory. In the 1960s, the Supreme Court ruled that banning the teaching of evolution was unconstitutional, and that the teaching of creationism was, in fact, an infiltration of religion into schools.
With the Dover trial just getting started in Harrisburg this past Monday, the historical parallels were striking. Zimmer noted that so-called “Intelligent Design” theorists, the modern equivalent of creationists from years past, have been arguing that “there is zero scientific fossil evidence that demonstrates organic evolutionary linkage between primates and man,” as Senator Christopher Buttars (R – Utah) stated recently.
On the contrary, Zimmer said, there exists significant fossil evidence demonstrating a continuum of modification from early primates to Homo sapiens. This began with Raymond Dart’s discovery of an Australopithicus skull in the early 1920s, and has continued to the present day, when a phylogenetic tree stretching back 7 million years and encompassing a dozen distinct hominid species can be constructed.
Zimmer progressed through a list of common creationist objections to an evolutionary origin for human beings, presenting scientific evidence to the contrary in each case. For example, he noted the extreme similarity between the genomes of humans and the chimpanzee, which exhibit a difference of only 3%, and described how, of the hundreds of smell receptors coded by genes in mammals, most are broken in humans, whereas all are functional in mice. This data is indicative of natural selection at work: as vision and other senses grew more important for hominids, mutations that deactivate smell receptors would be less and less deleterious to their fitness, allowing the mutated receptors to persist.
The lecture was not limited to presentation of factual data. Zimmer offered the conjecture that the sudden burst of evolutionary change starting approximately 200,000 years ago, which led to modern humans, was due at least in part to the development of language. This fostered communication and trade, and allowed humanity to spread throughout the world.
Zimmer concluded, “An entity with the power to create entirely new species from scratch creates something 6 million years ago that then goes extinct, repeating this many times… and then, 160,000 years ago, finally gets it right- well, that doesn’t seem like a very intelligent designer to me.” After the talk, Zimmer answered several questions from the audience, on subjects ranging from the use of “Smithsonian” in the title of his upcoming book to ways to improve the quality of the discourse in America.
Event organizer Adam Roddy ’06, a biology major, was pleased with the talk. “Without a scientific background Carl has been able to do what more journalists should do: namely, learn about their topic… He was able to talk about everything from the Central Dogma of biology to evolutionary trends in primate species, stopping at phylogenetic reconstructions and genomics along the way,” he stated.
Student response to the talk was also enthusiastic. Former biology major Katie Davenport ’05 called Zimmer “…a great speaker,” adding, “it’s always good to have more of these arguments up your sleeve.” Non-scientists were also impressed. Amara Telleen ’06 said, “I thought it was fascinating. Zimmer did a good job of making this subject accessible to everyone in the audience.”