Discovery of 'Ardi' is not news inside academic community

    The news media have been abuzz for the past few weeks with articles, documentaries and other features about the unearthing of a very old set of bones. The bones belong to Ardipithecus ramidus or, as she is commonly referred to, "Ardi." Her remains are the earliest of any hominid ever discovered.
    This revelation has been most exciting to the anthropological and archaeological communities, giving them fresh insight into how humans have evolved.
    But to many scholars within these fields, Ardi is old news.
    "It isn't a new discovery," said Stephen Bailey, associate professor of anthropology at Tufts. "We've been getting bits of descriptions for a long time now. And people who work in the field pretty much knew most of what was going to happen."
    People knew what was going to happen because, despite the recent hype, Ardi herself was actually discovered almost 15 years ago in Ethiopia. But the researchers had reservations about heavily publicizing the story until further study had been conducted. And completing satisfactory research took a long time — 15 years, to be precise.
    "They wanted to do such a detailed study and have it all out there," said Lauren Sullivan, a lecturer in Tufts' anthropology and archaeology departments. "The initial findings were released in 1994, [and] they put out press releases, that kind of thing. In the Science Magazine that came out recently, there were [about] 50 different scientists looking at her and doing analysis, and it takes a while to get that done and turn it into a publication."
    Bailey cited an additional reason for the length of time between discovery and release of information. "The cleaning is excruciatingly painstaking," he said.
    "It may take a year to clean something like a femur," he said, referring to a particular bone in the leg. "[It is] very tedious work, and you can't rush it."
    But now that the scientific community has conducted the research to support Ardi's weighty discovery, she is changing some of the most widely held perceptions about how humans evolved.
    A prevailing theory within anthropology for years has been the idea that bipedalism, or walking on two legs, developed when early hominids moved from the forest to the savannah. The idea was that early humans were scavengers, so being able to move around and carry things at the same time was an evolutionary advantage — especially for males, who could carry the groceries back to their chosen mates.
    But Bailey explained that the discovery of Ardi has altered this view. "Ramidus takes us away from that model — from the savannah into the forest. Ramidus quite clearly lived in the forest. You also see the morphology — the curved phalanges, [and] a skeleton that is probably equally as adept at going up a tree fast as it is walking on the ground," he said.
    Ardi's sheer age is also a significant factor in her academic importance. "One of the big things is the fact that they have a detailed analysis of an ancestor that's a million years older than ‘Lucy,'" Sullivan said. Lucy, found in 1974, was the oldest and most complete skeleton of an early hominid until Ardi's discovery.
    "Lucy is 3.2 million years old. Ardi is 4.4 million years old. Up until now Lucy was the largest portion of an individual that they'd found. She had 45 percent of her skeleton. So, with Ardi, they are able to get information on an individual going back about a million years," Sullivan said. Fossils even older than Ardi have been found, but they are fragments, making it more difficult to get an accurate vision of how the species lived.
    With a lack of fossils to study, it has been common practice for anthropologists to use chimpanzees as models for how early human ancestors would have behaved. Since the discovery of Ardi, many researchers have been rethinking that approach.
    "Since Ardi, chimpanzees have evolved along their own track, and humans have evolved too. Scientists hadn't necessarily realized that modern apes have evolved a lot more than previously thought," Sullivan said.
    Bailey referred to studying modern chimpanzees for their similarity to common ancestors as dangerous, since chimpanzees are so specialized.
    "They're knuckle walkers, they live in an increasingly marginalized environment, they're in danger of extinction. It's not clear that their behavior even in the wild is anything like it would have been 6 million years ago," Bailey said. "A long time ago, there were so many more of them that they could have been the successful ones, and we were the weird, offshoot population."
    Studying Ardi has allowed paleontologists to make great headway in their understanding of why humans have evolved the way they have, but the discovery also adds insight to the archaeological record. Archaeology is often thought of as the study of ancient buildings and artifacts, but Ardi lived 2 million years before the earliest manmade tools in the archaeological record.
    "This is just another kind of [archaeological] site, and this provides information about our ancestors way before buildings and way before we had social inequality and pottery and all the stuff that comes with that, so it gives people on the street that are just reading about it another perspective of what life was like many, many years before you see Homo sapiens," Sullivan said.
    "Most of the sites that people think about when you think about temples or pyramids are associated with modern Homo sapiens. When you're looking at human evolution and early bipedalism, you're pushing the record back millions of years ago and bringing in other species," Sullivan added.
    In the case of Ardi, Bailey said looking at how she lived matters because of the place she holds in history. "The large majority of physical anthropologists and human paleontologists see Ramidus as a direct ancestor of ours. There's a minority opinion that all of that line goes its own interesting direction and at best are [our] cousins. But I would say that in general people feel that she's on the main line — she becomes us," Bailey said.