Missing Link found?

[Adios]

An analysis of 2 million-year-old bones found in South Africa offers the most powerful case so far in identifying the transitional figure that came before modern humans — findings some are calling a potential game-changer in understanding evolution.

The bones are from Australopithecus sediba. The research places that pre-human branch of the evolutionary tree as the best candidate to be the ancestor of the human line, said Lee R. Berger of the University of Witwatersrand in South Africa.
http://www.msnbc.msn.com/id/44438221/ns/technology_and_science-science/#.Tmjqc-zlhQ0

This could alter things quite a bit.

[Cain]

More information from Wikipedia

Because of the wide range of mosaic features exhibited in both cranial and post cranial morphology, the authors suggest that A. sediba may be a transitional species between the southern African A. africanus (the Taung Child, Mrs. Ples) and either Homo habilis or even the later H. erectus (Turkana boy, Java man, Peking man).[2] The cranial capacity of MH1, which has been estimated to be at 95% of adult capacity (420 ml/cc), is at the higher end of the range for A. africanus and far from the lower range of early Homo (631 ml/cc), but the mandible and tooth size are quite gracile and similar to what one would expect to find in H. erectus, so similar that if found in isolation without other skeletal remains could be classified as Homo based on tooth and mandible size. However, the cusp spacing is more like Australopithecus. Another interesting example of the wide range of interspecific variation of this species is that although MH2 is an adult, the tooth size of MH1, the juvenile, is larger than that of the adult. Regardless of which species MH1 and MH2 belong to, the range of variation has been greatly increased with the finding of these new specimens.

A. sediba compared to its ancestor species A. africanus on the whole is described by Berger et al. as more derived towards Homo than A. garhi, especially showing a number of synapomorphies taken to anticipate the reorganization of the pelvis in H. erectus, associated with "more energetically efficient walking and running". The femur and tibia are fragmentary and the foot is more primitive.[2] Its cranial capacity is estimated at around 420–450 cm3 (26–27 cu in),[2] about one-third that of modern humans.

As opposed to the authors of the initial description, who interpreted both fossils as a possible transitional species between Australopithecus and Homo, other palaeoanthropologists are reluctant. In an accompanying news article, detractors of the idea that "Au. sediba" might be ancestral to the genus "Homo" (e.g. Tim White and Ron Clarke) suggest that the fossils could be a late southern African branch of Australopithecus, co-existing with already existing members of the Homo genus.[6] This interpretation is based on the observation that the lower jaw, discovered by Friedemann Schrenk, of a 2.5 million year old fossil attributed to H. rudolfensis is the oldest known fossil ascribed to the Homo genus. This specimen is thus presumed to be older than the Australopithecus sediba fossils. The critics, however continue to ascribe to A. africanus the status of precursor of the Homo genus. Criticism has been raised in a news report on the find in Nature magazine that the authors of the initial description have failed to take the wealth of variation within A. africanus into account, prior to defining the finds as an independent species.[7] Additionally, the basing of the description of the species largely on the skeleton of a juvenile specimen has been subject to criticism, given that there is no certain way of saying to what extent adults would differ from juvenile specimens. This has been a common practice in palaeoanthropology, with even the type specimens of Homo habilis and Australopithecus africanus being juvenile specimens.

[Adios]

This debate could go on for years.

[Dysfunctional Cunt]

This debate couldwill continue to go on for years.

[Telarus]

This debate couldwill continue to go on for years.

Is this a shared ancestor with us and Neanderthal?

I don't have that info off had, but if it ISN'T, then things have gotten MUCH MORE INTERESTING (recent news that non-african males carry traces of Neanderthal DNA).

I'm pretty sure odds are against that, tho....

[Dysfunctional Cunt]

This debate couldwill continue to go on for years.

Is this a shared ancestor with us and Neanderthal?

I don't have that info off had, but if it ISN'T, then things have gotten MUCH MORE INTERESTING (recent news that non-african males carry traces of Neanderthal DNA).

I'm pretty sure odds are against that, tho....

Did I miss that article?  Can you cross post pretty please....

[Kai]

This debate couldwill continue to go on for years.

Is this a shared ancestor with us and Neanderthal?

I don't have that info off had, but if it ISN'T, then things have gotten MUCH MORE INTERESTING (recent news that non-african males carry traces of Neanderthal DNA).

I'm pretty sure odds are against that, tho....

1) There are more than just 'sapiens' and 'neanderthalis' in the genus Homo. If this were a common ancestor, it would be the common ancestor of all the species in the genus Homo, which would include H. erectus, H. habilis, H. eregastor, etc.

2) As much as people like to talk about missing links and finding the ancestor of a particular group, there is never and will never be any evidence that a particular fossil find is of a species that is the ancestor of another. All we can say is, morphological evidence suggests that Australopithecus selba is more closely related to Homo than to other Austrailopithecus. The former is an untestable just so story.

3)Point two is actually a systematics problem, as this discovery would make Australopithecus a paraphyletic grouping and suggest it should be a subgenus of Homo.

[Telarus]

1) There are more than just 'sapiens' and 'neanderthalis' in the genus Homo. If this were a common ancestor, it would be the common ancestor of all the species in the genus Homo, which would include H. erectus, H. habilis, H. eregastor, etc.

2) As much as people like to talk about missing links and finding the ancestor of a particular group, there is never and will never be any evidence that a particular fossil find is of a species that is the ancestor of another. All we can say is, morphological evidence suggests that Australopithecus selba is more closely related to Homo than to other Austrailopithecus. The former is an untestable just so story.

3)Point two is actually a systematics problem, as this discovery would make Australopithecus a paraphyletic grouping and suggest it should be a subgenus of Homo.

Brilliant. I had actually run in to point 2 recently, but had forgotten about it until now. Remembering that this is a single datapoint in a millennial time-span is important. Thanks, Kai!


So, I find the shake-ups mentioned in the article interesting. Things like the assumed correlation between 'modern' brain structure and the loss of tree dwelling adaptations in the feet. This fossil disproves that. I wonder why that assumption was so unquestioned until now....

[Dalek]

An analysis of 2 million-year-old bones

Am I the only one who read this 2 million-year-old boners?