Ardi, Oldest Relative Sheds New Light On Human Evolution

Ardipithecus Ramidus

October 1st, 2009
WASHINGTON - Anthropologists took the wraps off the oldest known human ancestor Thursday - a 4.4-million-year-old Ethiopian skeleton named Ardi, which challenges many long-held assumptions about how humans and apes evolved.

Its not a chimp. Its not a human. It shows us what we used to be, said paleoanthropologist Tim White of the University of California-Berkeley, co-director of the research group that discovered and analysed more than 110 specimens of the 4.4-million-year-old species Ardipithecus ramidus.

White was speaking at a Washington press conference a day before a series of 47 articles on the find are published in the American journal Science.

Ardi is the most complete skeleton among the specimens and is more than a million years older than the famous Lucy skeleton uncovered in the 1970s. She was found in 1992 in Ethiopias harsh Afar desert at a site called Aramis, just 74 km from where Lucys species, Australopithecus afarensis, was found in 1974.

An initial paper was published in 1994, but the fossils were so fragile it took a further 15 years to reconstruct Ardis skeleton and analyse it.

The findings provide scientists with information on what a common ancestor for humans and apes may have been like, with a mix of traits from earlier species and later species.

But Ardi and her species were less like modern apes than scientists expected - indicating that apes likely evolved extensively after scientists say the apes and humans diverged. This challenges the long-standing scientific belief that apes give a good look at what an early ancestor of humans may have looked like.

Small-brained, 120 cm tall and weighing about 50 kg, Ardipithecus ramidus lived in a wooded environment, climbing on all fours in the trees and walking on two feet on the ground, not walking on their knuckles like gorillas or swinging from the trees like chimps.

So when you go from head to toe, youre seeing a mosaic creature, that is neither chimpanzee, nor is it human. It is Ardipithecus, White said.

Darwin said we have to be really careful. The only way were really going to know what this last common ancestor looked like is to go and find it.

Well, at 4.4 million years ago we found something pretty close to it. And, just like Darwin appreciated, evolution of the ape lineages and the human lineage has been going on independently since the time those lines split, since that last common ancestor we shared, White said.

Category:

Science & Technology

Tags:

• Ardi
• Ardipithecus
• Ramidus
• UC
• Berkeley
• Human
• Evolution

[gregrutz]

Sahelanthropus tchadensis, Orrorin tugenensis, Ardipithecus ramidus, Australopithecus anamensis, Australopithecus afarensis, Kenyanthropus platyops, Australopithecus africanus, Australopithecus garhi, Australopithecus aethiopicus, Australopithecus robustus, Australopithecus boisei, Homo habilis, Homo georgicus, Homo erectus, Homo ergaster, Homo antecessor, Homo heidelbergensis, Homo floresiensis.

[gregrutz]

It is the discovery process, lol

You creationists want more 'missing links', and when they find one you say, I thought that last one was a transitional fossil. We are filling in the gaps every day.

[parador5859]

@dennisjiewenliu i totally agree! everyone who says its a person, ITS NOT!!!!!

[parador5859]

you guys do realize that it is just a monkey!!!! its not a human!!!!

[gregrutz]

@Cypherus21 Humans are primates, of course our ancestors will be primates too.

The drawing and artists interpretations are for really slow and stupid people with no imagination. They are all based on the fossilized bones.

How do you expalin the 4 million year old fossil?

[Cypherus21]

@gregrutz

CG renders or artist interpretations are not "missing links." The bones are obviously that of an early primate that did not walk upright. Since no spinal bones were found, the scientists just made a subjective inference that it walked upright just to create another arbitrary "link" in the evolutionary path of humans.

[bloodstone1445]

4,500,000 years .... god we have come a long way.

[FreeeeS]

I would like to read this go to my twitter account coz i allready follow NS SCIAM DAWKINSNET NASA etc :P

[saladooq]

@gregrutz yes we are.

[mystisme]

we were never monkeys but a vipedal apes and ij we go a little farther and foud another apes skalatin you ll find out yhat the toes was like ours ardi was the begginning of the separation between apes and monkeys

[trollundatheolbridge]

@arsjth lol

[trollundatheolbridge]

@arsjth nope, upright walking apes are considered to be human