Orangutan-mankind link revived in exhibit
[Cincinnati Post]
The idea that the orangutan is mankind's closest relative has never been popular in the scientific mainstream. In fact, when University of Pittsburgh anthropologist Jeffrey Schwartz first advanced the idea 20 years ago, many colleagues rejected it out of hand, citing analyses that the genomes of chimpanzees and humans are almost 99 percent identical, while orangutans are genetically distinct.
But Schwartz's orangutan theory of human origins is not forgotten and last week got renewed attention at the Buffalo Museum of Science. As part of a developing exhibit on human origins, the New York museum unveiled a painting that depicted a fleshed-out version of Australopithecus afarensis. The 3.2 million-year-old fossil, popularly known as Lucy, may be the oldest common ancestor in the human family.
Unlike earlier reconstructions that favored chimp-like features, this version by the museum's scientific illustrator, William Parsons, looks more like an orangutan. "It shows," said John Grehan, the museum's director of science and collections, "that you can get more than one answer out of the same evidence."Neither the exhibit nor the painting is an endorsement of the orangutan theory, he emphasized, but they are meant to acquaint the public with competing theories of human origins, as well as provide some insights into the sociology of science.
"Every idea starts as a minority point of view," Grehan said, and sometimes ideas get overlooked or rejected because of scientific mindsets or assumptions. The orangutan theory, for instance, "isn't getting traction, but it's not necessarily the fault of the evidence."
Schwartz, a physical anthropologist who has been on the Pitt faculty for 30 years, based his theory on the morphological similarities -- the physical characteristics -- of humans and orangutans, not on their genes. The orangutan, a name that means "man of the forest," is an endangered species. About 4-1/2 feet tall, orangutans are shy, reddish-haired apes that live in the trees on the Indian Ocean islands of Borneo and Sumatra.
Schwartz counts more than three dozen features that are shared uniquely by orangutans and humans, from the ridges on the bottoms of their feet to the floor of their nasal passages.
The reconstruction unveiled last week was not based on Lucy, a partial skeleton missing a skull unearthed in Ethiopia by Donald Johanson in 1974. The new painting was based on a scan of another Australopithecus fossil, known as AL444-2, which was found at the same site as Lucy. Its skull is "very oranglike," Schwartz said, with front-facing cheekbones and a flat facial plane below the eye sockets. The brow ridges are thin, like those of orangs and humans, so they don't stick out like those of chimps and gorillas.
"Nobody is saying that Lucy is an orang," Schwartz said. Still, the similarities are intriguing, he maintained. Other anthropologists aren't necessarily any more intrigued with the orangutan theory now than they were in 1984, when Schwartz outlined it in a paper in the prestigious journal Nature, or in 1987, when his book on the subject, "The Red Ape: Orangutans and Human Origins," was published.
"I'm not aware that anyone has given Jeff's idea more thought since the initial discussion and I don't think that anything has happened in the intervening years that would lead to it being more likely to be reconsidered," Andrew Hill, chairman of anthropology at Yale University, said last week.
"There is absolutely no evidence to refute the well-established finding that humans and chimpanzees are most closely related," agreed Maryellen Ruvolo, a biological anthropologist at Harvard University.