Epic Old Friend From Long Long Ago Win

Scientists have found the bones of a 1.2 million year old plus relative of humanity. "Ardi" is not quite the missing link, but it's a major find for evolutionary science.

In a series of studies published in the Oct. 2 special issue of Science — 11 papers by a total of 47 authors from 10 countries — researchers unveiled Ardi, a 125-piece hominid skeleton that is 1.2 million years older than the celebrated Lucy (Australopithecus afarensis) and by far the oldest one ever found. Tim White of the University of California, Berkeley, a co-leader of the Middle Awash research team that discovered and studied the new fossils, says, "To understand the biology, the parts you really want are the skull and teeth, the pelvis, the limbs and the hands and the feet. And we have all of them."

That is the beauty of Ardi — good bones. The completeness of Ardi's remains, as well as the more than 150,000 plant and animal fossils collected from surrounding sediments of the same time period, has generated an unprecedented amount of intelligence about one of our earliest potential forebears. The skeleton allows scientists to compare Ardipithecus directly with Lucy's genus, Australopithecus, its probable descendant. Perhaps most important, Ardi provides clues to what the last common ancestor shared by humans and chimps might have looked like before their lineages diverged about 7 million years ago.

Ardi is the earliest and best-documented descendant of that common ancestor. But despite being "so close to the split," says White, the surprising thing is that she bears little resemblance to chimpanzees, our closest living primate relatives. The elusive common ancestor's bones have never been found, but scientists, working from the evidence available — especially analyses of Australopithecus and modern African apes — envisioned Great-Great-Grandpa to have looked most nearly like a knuckle-walking, tree-swinging ape. But "[Ardi is] not chimplike," according to White, which means that the last common ancestor probably wasn't either. "This skeleton flips our understanding of human evolution," says Kent State University anthropologist C. Owen Lovejoy, a member of the Middle Awash team. "It's clear that humans are not merely a slight modification of chimps, despite their genomic similarity."

This is some pretty cool stuff here, and an important find, potentially.

EPIC WIN.