Homo ancestor?

Could they have found the missing link?

Quote :

Possible human relative, 2 million years old, a ‘snapshot of evolution in action’

He was built to climb, and yet he strode upright.

His arms hung low like an orangutan’s. Yet with his long thumbs and curved fingers he could grasp sticks and rocks like a man.

His brain was not much larger than a chimpanzee’s. Yet his widened pelvis implied his kind gave birth to children with much bigger brains.

And so a fossilized adolescent named Karabo — which means “answer” in a South African dialect — is raising a lot of questions about human evolution.

Researchers found his skeleton, and much of an adult female, in a cave some 25 miles north of Johannesburg in 2008 and announced the discovery in 2010. They coined a new species, Australopithecus sediba, and launched an intensive multi-national effort to study the find.

In the journal Science, the team is now publishing detailed descriptions of the creatures’ heads, hands, feet, and hips. The team also date the fossils to 1.98 million years ago, smack in the middle of an era notorious for its lack of evidence of possible human relatives.

The mash-up of human-like and ape-like traits are like a “a stop-action snapshot of evolution in action,” said the director of the Smithsonian Institution’s Human Origins Program, Richard Potts, who was not involved in the research.

The researchers stop just short of calling the creatures an ancestor to the human lineage known as Homo. But they place A. sediba squarely in the running for that coveted title.

The species is “possibly the best candidate” yet for a Homo ancestor, said Lee Berger of the University of Witswatersrand in Johannesburg. Berger, along with his then-9-year-old son Matthew, discovered Karabo in a fossil-rich region known as the Cradle of Humankind.

None of the previous finds were preserved like this. The duo apparently fell into a deep cave together, where limestone encased the bodies and preserved exquisite detail.

The fossils are “mouth-watering for anybody in this business,” said Donald C. Johanson, director of the Institute of Human Origins at Arizona State University.

Based on his size, Karabo was just entering adolescence. His companion was an adult female. It’s tempting to think of them as mother and son. Berger said they are “likely related,” although he presented no evidence other than their proximity in death.

The foot and ankle are “mostly human,” said Bernhard Zipfel, also of the University of Witswatersrand. And yet, the heel looks more ape-like — one of many such anomalies.

The knee lined up above the ankle, not angled out as in apes, a giveaway that the creatures walked upright. And yet, bumps on the inside of the ankle and other features mark the ankle as more chimp-like, the “type of ankle you need to climb a tree,” Zipfel said.

The thumb was long relative to the fingers — even longer than ours. The fingers curved, suggesting a powerful grasp. The combination gave the creatures “precision grip” like we need for wielding a pen. Tool-making “was possible,” said Tracy Kivell of the Max Planck Institute for Evolutionary Anthropology in Germany, although the scientists have found no stone tools.

More here...
http://www.washingtonpost.com/national/health-science/possible-human-relative-2-million-years-old-a-snapshot-of-evolution-in-action/2011/09/07/gIQAzCNACK_story_1.html

I thought this was going to be about a different topic.