Pitt anthropologist thinks Darwin’s theory needs to evolve on some points
Monday, May 29, 2006
By Mark Roth
Darwin was wrong, and his modern-day adherents perpetuate his mistakes.
That sounds like the opening salvo of an advocate for Intelligent Design or some other religiously driven critique of the theory of evolution.
But it actually summarizes the ideas of Jeffrey Schwartz, a noted anthropologist at the University of Pittsburgh and one of a growing group of critics of standard Darwinian theory.
Most of the recent publicity Dr. Schwartz has received has focused on his role in creating life-sized replicas of George Washington for display at Mount Vernon.
Much of his career, though, has been devoted to human evolution and the history of Charles Darwin’s ideas.
In criticizing Darwin, Dr. Schwartz does not dispute his theory that humans, animals and plants evolved from other species. In fact, one of his books, “The Red Ape,” argues that orangutans, not chimpanzees, are the closest evolutionary relatives of human beings.
He does take issue with two key parts of traditional Darwinian thinking, though — gradualism and adaptation.
Gradualism holds that new species evolve from their ancestors through tiny, incremental changes. Adaptation says those changes come in response to shifting conditions in the environment. [This is all the opening ID needs. –WmAD]
“We have abundant evidence,” Darwin wrote in one of his books, “of the constant occurrence under nature of slight individual differences of the most diversified kinds; and we are thus led to conclude that species have generally originated by the natural selection of extremely slight differences.”
Dr. Schwartz said he has two problems with that view.
First, if evolution were gradual, there should be a record of continuous changes in prehistoric fossils, but there are many gaps between species in the fossil record.
Darwin said it was simply bad fortune that those intermediate fossils were missing. Scientific creationists have used the fossil gaps to argue that God created species separately, as described in the Book of Genesis.
But there is another possibility, Dr. Schwartz said. There isn’t a huge number of missing transitional fossils because they were never there in the first place. Instead, new species emerged suddenly due to genetic alterations that created sharp differences with their predecessors.
Another problem with gradualism, he argued, is that it suggests that complex structures, such as a vertebrate’s eyes or a mammal’s mammary glands, had thousands of slightly different precursors in earlier creatures. That defies logic, he said. Modern evolutionary thinkers like Niles Eldredge and the late Stephen Jay Gould dealt with the fossil gaps by coming up with the theory of “punctuated equilibrium.” Creatures evolved pretty much the way Darwin had described, they said, but not at a steady pace. Sometimes there would be fallow periods; sometimes there would be profligate explosions of new species.
That concept still embraced the idea of adaptation, though, Dr. Schwartz said — that changes in environmental conditions drive “natural selection” by favoring the survival of species best suited to those conditions.
He has an alternative view.
Dr. Schwartz contends that new organisms are probably generated by random changes in developmental genes, and that any new features they have will remain in existence as long as they don’t hurt the creatures’ chances of survival.
“Basically,” he said, “if a feature doesn’t kill you, you’ll continue to have it.”
Rather than the environment causing species to change by favoring one type of creature over another, he said, it’s just as likely that a creature produced by random evolution can survive in different environments.
His favorite example is the mongoose lemur, found on Madagascar and the Comoros Islands off the coast of Africa. On Madagascar, these lemurs are active in the day, eat fruits and leaves and travel around on the ground. In the Comoros, they are active at night, stay in trees, and feed by hanging upside down from their hind feet to suck nectar out of flowers.
“This kind of shift is actually quite common,” he said. “These lemurs have the same teeth, the same feet, the same eyes, but if the environment changes, they change their activity and their diet, not their anatomy.”
Dr. Schwartz thinks there are a couple reasons why he and other contrarian evolutionary thinkers have not reached the public consciousness.
For one thing, they don’t all agree with each other, so they have never developed a unified front.
Also, the challenge to evolutionary thinking in recent decades from advocates of Intelligent Design and creationism have impelled many scientists to band together in defense of Darwin’s ideas, shoving alternative theories to the background.
As passionate as Dr. Schwartz is about evolution, it is only one of his eclectic interests. A short list of other projects:
The George Washington project, which he wrote about in the February issue of Scientific American, is almost ready to be unveiled. The wax figures of Washington at the ages of 19, 45 and 57 were developed with the help of Dr. Schwartz’s expertise on how the president’s face would have changed because of aging and his notoriously poor teeth. They will be put on display in October.
As an expert in studying bones to help with criminal investigations, he has watched the rise of the “CSI” television shows with concern and amusement. The net effect of the programs has probably been to “raise unrealistic expectations” as to how effective forensic evidence can be in solving crimes, he said — “plus the fact that when I go to the coroner’s office, nobody looks like anyone on those television shows.”
He and several co-authors just completed a four-volume study of the entire human fossil record. Asked about why Neanderthals disappeared after nearly 200,000 years of existence, he said: “I think our species killed them. We’re a bellicose species and an intolerant one and I wouldn’t be surprised if we had pushed this other species into refuges and wiped them out.”
Dr. Schwartz said he doesn’t know whether his evolutionary ideas will ever become part of the mainstream, but he nevertheless thinks they are good for science.
“I think it was George Patton who said, ‘If everybody’s thinking the same thing, then nobody’s thinking.’ And I believe that’s the problem with this Darwinian thinking that puts all the eggs in one basket.”
Name: Jeffrey H. Schwartz
Position: Professor of anthropology, University of Pittsburgh, 32 years.
Education: Bachelor’s, Columbia College, 1969; master’s and Ph.D. in anthropology, Columbia University, 1973-74.
Previous positions: Consultant in forensic anthropology, Allegheny County coroner’s office, 1998 to present; Visiting distinguished professor, University of Alabama, 2003; Visiting professor, University of Vienna, 2005.
Publications: Several books, including “The Human Fossil Record” (four volumes), 2002-05; “Sudden Origins: Fossils, Genes and the Emergence of Species” (1999); “The Red Ape” (1987, updated 2005), and 140 refereed journal articles and chapters.
Professional honors: Best single reference work in the sciences, American Association of Publishers, 2003; Distinguished lecturer, Gesellschaft fur Anthropologie, 1998; Honorary medal, College de France, 1989.