Ardi-Ardipithecus ramidus and human evolution

The story of humankind is reaching back another million years as scientists learn more about "Ardi," a hominid who lived 4.4 million years ago in what is now Ethiopia. The 110-pound, 4-foot female roamed forests a million years before the famous Lucy, long studied as the earliest skeleton of a human ancestor.

This older skeleton reverses the common wisdom of human evolution, said anthropologist C. Owen Lovejoy of Kent State University.

Rather than humans evolving from an ancient chimp-like creature, the new find provides evidence that chimps and humans evolved from some long-ago common ancestor — but each evolved and changed separately along the way.

"This is not that common ancestor, but it's the closest we have ever been able to come," said Tim White, director of the Human Evolution Research Center at the University of California, Berkeley.

The lines that evolved into modern humans and living apes probably shared an ancestor 6 million to 7 million years ago, White said in a telephone interview.

But Ardi has many traits that do not appear in modern-day African apes, leading to the conclusion that the apes evolved extensively since we shared that last common ancestor.

A study of Ardi, under way since the first bones were discovered in 1994, indicates the species lived in the woodlands and could climb on all fours along tree branches, but the development of their arms and legs indicates they didn't spend much time in the trees. And they could walk upright, on two legs, when on the ground.

Formally dubbed Ardipithecus ramidus — which means root of the ground ape — the find is detailed in 11 research papers published Thursday by the journal Science.

"This is one of the most important discoveries for the study of human evolution," said David Pilbeam, curator of paleoanthropology at Harvard's Peabody Museum of Archaeology and Ethnology.

"It is relatively complete in that it preserves head, hands, feet and some critical parts in between. It represents a genus plausibly ancestral to Australopithecus — itself ancestral to our genus Homo," said Pilbeam, who was not part of the research teams.

Scientists assembled the skeleton from 125 pieces.

Lucy, also found in Africa, thrived a million years after Ardi and was of the more human-like genus Australopithecus.

• Ardi was found in Ethiopia's Afar Rift, where many fossils of ancient plants and animals have been discovered. Findings near the skeleton indicate that at the time it was a wooded environment. Fossils of 29 species of birds and 20 species of small mammals were found at the site.

• Geologist Giday WoldeGabriel of Los Alamos National Laboratory was able to use volcanic layers above and below the fossil to date it to 4.4 million years ago.

• Ardi's upper canine teeth are more like the stubby ones of modern humans than the long, sharp, pointed ones of male chimpanzees and most other primates. An analysis of the tooth enamel suggests a diverse diet, including fruit and other woodland-based foods such as nuts and leaves.

• Paleoanthropologist Gen Suwa of the University of Tokyo reported that Ardi's face had a projecting muzzle, giving her an ape-like appearance. But it didn't thrust forward quite as much as the lower faces of modern African apes do. Some features of her skull, such as the ridge above the eye socket, are quite different from those of chimpanzees. The details of the bottom of the skull, where nerves and blood vessels enter the brain, indicate that Ardi's brain was positioned in a way similar to modern humans, possibly suggesting that the hominid brain may have been already poised to expand areas involving aspects of visual and spatial perception.

• Ardi's hand and wrist were a mix of primitive traits and a few new ones, but they don't include the hallmark traits of the modern tree-hanging, knuckle-walking chimps and gorillas. She had relatively short palms and fingers which were flexible, allowing her to support her body weight on her palms while moving along tree branches, but she had to be a careful climber because she lacked the anatomical features that allow modern-day African apes to swing, hang and easily move through the trees

Category:

Science & Technology

Tags:

• ardi
• evolution
• human
• apes
• relative
• ancestor

[shorty962]

there are more then one missing link. I'll show you Homo Sapien Sapien Homo Sapien---------Cro Magnon Homo Sapien Idaltu Homo Rhodesiensis Homo Heidelbergensis Homo Cepranensis Homo Georgicus Homo Erectus Homo Antecessor Homo Ergaster Homo Habilis Homo Rudolfensis

[Sundriedpuppy]

@velvett-

Comparing the entire genome IS looking at the bigger picture. It's not so much the number of chromosomes as the content of the entire genome that signifies evolutionary lineage.

The fact that we have the same number of chromosomes as a deer is almost completely irrelevant, considering a very close relative to that deer (the Indian Muntjac) has 6-7 chromosomes, depending on gender.

And no, I didn't just know that. I was curious and Googled it. Hooray, technology! Hooray, humans!

[SadieMack1]

Of old You laid the foundation of the earth, and the heavens are the work of You hands. They will perish, but You will endure; Yes, they will all grow old like a garment; Like a cloak You will change them and they will be changed. But You are the same, and Your years have no end. Psalm 102: 25-27. One point about evolution that seems to be overlooked is that when the creation evolves, the old creature no longer exists.

[countrygalcm]

ardi lived in the trees

[deadontime70]

humans and apes shared a common ancestor 6 or 7 milion yrs ago depending on who you asked than in the area of the rift valley we suddenly had to stand to get food and we started walking ,of course we were not there ,but thats what happened,oh and before we were apes we were fish than we came on land watch mr garrison interpation of human evolution

[BackInTheCage]

@deadontime70 Humans are apes.

[BackInTheCage]

@deadontime70 Humans are apes.

[ronocko]

@tarik102001 ... are you serious or trolling? I'd just like to know.

and not all religions believe in Adam.

[RedlineMMA]

@tarik102001

Really??

It says all the animals were created instantaneously, & Eve was made from Adams rib.

everything know about science & history demolishes the fairytale stories of the bible.

[deadontime70]

late sorry but they admit this was an ape not realtion to humans?

[tarik102001]

there is no contradiction between evoplution and religion!!!!!... why do atheist base their stupid ide aof the no god on the evolution? ... nothing in religions say how god created Adam ... !!!!

[afterray]

wow. this science is hard to ignore.