Missing Link disproved, and intermediate form found

Recently, we bilaterally symmetrical bipeds were introduced to another family member, Ardipithecus Ramidus, who has a striking family resemblance to ourselves and our near cousin, the chimpanzee, without really being like either of us, so much.



Anyway, she reminds us that chimps are chimps and we are homo sapiens, and that the common ancestor we share might not really be so much like either of us.

The fossil puts to rest the notion, popular since Darwin's time, that a chimpanzee-like missing link—resembling something between humans and today's apes—would eventually be found at the root of the human family tree. Indeed, the new evidence suggests that the study of chimpanzee anatomy and behavior—long used to infer the nature of the earliest human ancestors—is largely irrelevant to understanding our beginnings.

Ardi instead shows an unexpected mix of advanced characteristics and of primitive traits seen in much older apes that were unlike chimps or gorillas (interactive: Ardi's key features). As such, the skeleton offers a window on what the last common ancestor of humans and living apes might have been like.

She was small, she was a palm-walker, not a knuckle-walker, and she and her male mates probably had a more sophisticated (and somewhat familiar to us, courtship ritual) regarding males bringing home the bacon--

But Ardipithecus appears to have already embarked on a uniquely human evolutionary path, with canines reduced in size and dramatically "feminized" to a stubby, diamond shape, according to the researchers. Males and female specimens are also close to each other in body size.

Lovejoy sees these changes as part of an epochal shift in social behavior: Instead of fighting for access to females, a male Ardipithecus would supply a "targeted female" and her offspring with gathered foods and gain her sexual loyalty in return.

To keep up his end of the deal, a male needed to have his hands free to carry home the food. Bipedalism may have been a poor way for Ardipithecus to get around, but through its contribution to the "sex for food" contract, it would have been an excellent way to bear more offspring. And in evolution, of course, more offspring is the name of the game (more: "Did Early Humans Start Walking for Sex?").

I think this is a wonderful find. "Ardi" is no "missing link", she is just a progenitor that sheds more light on how we homo sapiens came to be. She's a "found link" to the past.