By: Michael D. Lemonick Thursday, April 8, 2010
A nearly complete fossilized skull of a 11- to 13-year-old boy, of a new species of early Australopithecus hominid discovered in the Cradle of Humankind, outside Johannesburg, South Africa. The skull is approximately 1.9 million years old. Brett Eloff Photography
The truth is that paleontologists have found transitional species by the score, from many different time periods. But none have materialized from as crucial a point in our evolutionary past as a pair of skeletons whose discovery was announced today by the journal Science.(See the top 10 scientific discoveries of 2009.)
The fossils, which have been determined to be a new species, Australopithecus sediba, were initially found by Matthew Berger, the 9-year-old son of paleontologist Lee Berger of South Africa's University of the Witwatersrand (the elder Berger tried in vain to get the editors of Science to list Matthew as a co-author on the paper). The bones belong to a pre-teenage boy and a woman estimated to be in her late 20s or early 30s; the individuals died at about the same time, and before their remains had fully decomposed, they were entombed in an avalanche of sediment and nearly perfectly preserved deep in the Malapa cave north of Johannesburg, South Africa.
The Au. Sediba bones are important for their vintage — they date back to the moment about 2 million years ago, when the genus of human ancestors known as Australopithecus was just giving way to a new group called Homo, which would ultimately produce Homo sapiens, or modern humans.(See the top 10 animal stories of 2009.)
But the new find is perhaps most astonishing for its state of preservation. "These are arguably the most complete hominid skeletons ever discovered," says Berger.
In the field of human origins, that's huge: many human ancestors have been identified based only on a few bone fragments, and even Berger's rivals in the intensely competitive field of human paleontology were quick to praise his discovery. "This is an outstanding find and Lee should really be congratulated," says Meave Leakey, a paleontologist with the National Museums of Kenya, and a member of the world's most celebrated fossil-hunting family.
Other paleontologists have confirmed the dating of the skeletons to somewhere between 1.95 and 1.78 million years before the present, which is another crucial clue to figuring out the new species' place in our evolutionary story. That's where things get a lot more contentious.
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Berger suggests the tantalizing possibility of testing the fossils' DNA. Although the oldest DNA that paleontologists have successfully recovered so far dates back only tens of thousands of years, Berger said at a press conference, "We have states of preservation here that are truly extraordinary." But is it even possible to retrieve 2-million-year-old DNA? It's a long shot, he said, "but we're treating it as though maybe it could be preserved."
Read more here/Leia mais aqui: Time
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NOTA DESTE BLOGGER:
Apoiamos irrestritamente a ideia de Berger de submeter o Australopithecus sediba a testes de DNA. Afinal de contas, a ciência se move através de ousadas iniciativas. A ciência move do contexto da descoberta para o contexto da justificação teórica. Proponho teste de DNA nele, já! Darwin aprovaria 100% esta minha proposição!
