Agrippina wrote:The reason I heard them give for it's not being 'homo' but rather Australopithecine is because of the arms, they're longer than they would be for 'homo.' Or rather that was one reply I heard them give there were others, but I don't remember so I won't commit myself but I do remember about the arms.

Although the skull and skeleton of Au. sediba do evince derived features shared with early Homo, the overall body plan is that of a hominin at an australopith adaptive grade. This supports the argument, based on endocranial volume and craniodental morphology, that this species is most parsimoniously attributed to the genus Australopithecus.

Postcranially, Au. sediba is similar to other australopiths in its small body size, its relatively long upper limbs with large joint surfaces, and the retention of apparently primitive characteristics in the upper and lower limbs

The minimum cranial capacity of MH1 is estimated at 420 cm3.

Taxonomic diagnoses and phylogenetic interpretations are generally
based on craniodental remains, which necessitate such a focus even in taxa such as Au. sediba
that preserve a more complete representation of the skeleton. This is not to say, however, that
postcranial attributes cannot enlighten phylogenetic studies, and for these reasons the
significance of the postcranial morphology of Malapa is discussed. What is important is that the
postcranial remains support phylogenetic inferences derived from study of the craniodental
material.

The closest morphological comparison for Au. sediba is Au. africanus, as these taxa share numerous similarities in the cranial vault, facial skeleton, mandible, and teeth.

...we consider Au. sediba to be more appropriately positioned within Australopithecus, based on the following craniodental features: small cranial capacity, pronounced glabelar region, patent premaxillary suture, moderate canine jugum with canine fossa, small anterior nasal spine, steeply inclined zygomaticoalveolar crest, high masseter origin, moderate development of the mesial marginal ridge of the maxillary central incisor, and relatively closely spaced premolar and molar cusps.

Au. afarensis. The samples attributed to Au. afarensis from Hadar, Laetoli, and the Middle
Awash were utilized. For this taxon we relied on published reports (7) and casts.
Au. africanus. The samples attributed to Au. africanus from Taung, Sterkfontein and
Makapansgat were employed. Original specimens were examined first-hand.
Au. garhi. The cranium BOU-VP-12/130 from Bouri was included, with data taken from a
published report (8).
Au. aethiopicus. The cranium KNM-WT 17000 was examined first-hand for this study.
Au. boisei. Samples from the Omo Shungura sequence, East Lake Turkana, and Olduvai Gorge
were included in this study. Original specimens from East Lake Turkana were examined firsthand,
while casts and published reports (9) were used to study the Omo and Olduvai materials.
Au. robustus. The samples from Kromdraai, Swartkrans, Sterkfontein, Drimolen, Gondolin, and
Coopers were included in this study. First-hand observations of original specimens from all
localities were used with the exception of Drimolen fossils, which were compared using
published reports (10, 11).
H. habilis. Samples from Olduvai Gorge, East Lake Turkana, the Omo Shungura sequence, and
Hadar were included in this study. Original East Lake Turkana fossils were examined first-hand,
while for the Olduvai, Omo, and Hadar materials we relied on casts and published reports (12,
13, 14). We include the following fossils in the hypodigm of H. habilis: AL 666-1, KNM-ER
1478, KNM-ER 1501, KNM-ER 1502, KNM-ER 1805, KNM-ER 1813, KNM-ER 3735, OH 4,
OH 6, OH 7, OH 13, OH 15, OH 16, OH 21, OH 24, OH 27, OH 31, OH 37, OH 39, OH 42,
OH 44, OH 45, OH 62, and OMO-L894-1.
H. rudolfensis. Samples from Olduvai Gorge, East Lake Turkana, and Lake Malawi were
included in this study. The East Lake Turkana fossils were examined first-hand, while for the
Olduvai and Lake Malawi fossils we relied on casts and published reports (15, 16). We include
the following fossils in the hypodigm of H. rudolfensis: KNM-ER 819, KNM-ER 1470, KNMER
1482, KNM-ER 1483, KNM-ER 1590, KNM-ER 1801, KNM-ER 1802, KNM-ER 3732,
KNM-ER 3891, OH 65, and UR 501.
H. erectus. Samples from Baringo, Chemeron, Dmanisi, East and West Lake Turkana, Konso,
Olduvai Gorge, Sangiran, Swartkrans, Tighenif, Trinil, and Zhoukoudian were included in this
study. In particular, the following specimens from Swartkrans are considered to represent Homo
erectus: SK 15, SK 18a, SK 27, SK 43, SK 45, SK 68, SK 847, SK 878, SK 2635, SKW 3114,
SKX 257/258, SKX 267/2671, SKX 268, SKX 269, SKX 334, SKX 339, SKX 610, SKX 1756,
SKX 2354, SKX 2355, SKX 2356, and SKX 21204. It has been suggested (17, 18) that SK 847
and Stw 53 might represent the same taxon, and that this taxon is a currently undiagnosed
species of Homo in South Africa. However, we agree with Clarke (19, 20) that SK 847 can be
attributed to H. erectus, and that Stw 53 represents A. africanus. Since there is no clear indication
that more than one species of Homo is represented in the Swartkrans sample, we consider all this
material to belong to H. erectus. Original Baringo, Chemeron, Lake Turkana and Swartkrans
fossils were all examined first-hand, while the remainder were based on casts and published
reports (21, 22, 23, 24, 25).

John Hawks wrote:Here's the important thing. From today forward, there are a bevy of features of the face, teeth and jaw that are no longer "derived characters" of Homo.
Some people will want to fix this by broadening the definition to Homo to include the Malapa skeletons. Others will want to narrow the definition of Homo to include only large-brained specimens.
Every specimen attributed to Homo before 2 million years ago is now up for grabs. Maybe they're Homo, or maybe their resemblances to Homo are just masticatory parallelism. We already know that parallelism explains many of the derived locomotor and masticatory resemblances of great apes, and many strongly suspect that parallelism explains the derived masticatory resemblances of robust australopithecines. If the dental reduction that once was a marker of Homo joins this list, it will hardly be surprising.

Steviepinhead wrote:Are you looking at the various news reports and blog discussions, or are you working off of the papers themselves?

Though I'm not utterly unsympathetic to Au. habilis, there are more species, even in the early history of the genus Homo, than habilis and erectus. Whither ergaster, rhodesiensis, Dmansi, rudolfiensis, floresiensis, and others?

Tyrannical wrote:One thing that seems to get over looked is that by not classifying this discovery as Homo, it calls into question if some other earlier fossils should not have been classified as Homo.

http://johnhawks.net/weblog/fossils/sediba/malapa-berger-description-2010.html

John Hawks wrote:Here's the important thing. From today forward, there are a bevy of features of the face, teeth and jaw that are no longer "derived characters" of Homo.
Some people will want to fix this by broadening the definition to Homo to include the Malapa skeletons. Others will want to narrow the definition of Homo to include only large-brained specimens.
Every specimen attributed to Homo before 2 million years ago is now up for grabs. Maybe they're Homo, or maybe their resemblances to Homo are just masticatory parallelism. We already know that parallelism explains many of the derived locomotor and masticatory resemblances of great apes, and many strongly suspect that parallelism explains the derived masticatory resemblances of robust australopithecines. If the dental reduction that once was a marker of Homo joins this list, it will hardly be surprising.

Berger said French scientist, Dr Paul Tafforeau, based at the ESRF, suspected that the juvenile's brain was still intact.

http://www.msnbc.msn.com/id/36421160/ns/technology_and_science-science/:

Remains of a 1.9-million-year-old human ancestor are so well preserved that they may contain a remnant of the male individual's brain, according to the European Synchrotron Radiation Facility in Grenoble, France, where the remains were recently examined.

While DNA is very fragile and deteriorates over time, the discovery opens up the remote possibility that soft tissue with preserved DNA still exists in the prehistoric hominid, which could hold an important place on the human family tree.

The examination also turned up what seemed to be fossilized insect eggs, according to scientists. They said larvae from the eggs could have fed on the flesh of the human ancestor, Australopithecus sediba, right after his death.

Note, however, that the remarkable thing here is the possible preservation of informative soft tissue detail for that LONG a period of time, and that no doubt is manifested as to the 1.9 Mya age attribution.

While further testing is needed, the researchers believe an "extended shadow" hints that a remnant of the brain after its bacterial decay is still present in the ancient remains.

An expert on fossil brain tissue was asked for his views on this latest aspect of the australopith discovery:

[Alan] Pradel [of Paris' National Museum of Natural History] was one of the scientists who recently discovered a 300-million-year-old fossilized brain in a now-extinct relative of a modern "ghost shark" chimaera.

"Soft tissue has fossilized in the past, but it is usually muscle and organs like kidneys because of phosphate bacteria from the gut that permeates into tissue and preserves its features," added the American Museum of Natural History's John Maisey, who worked with Pradel in identifying the chimaera brain, which is now believed to be the world's oldest fossil brain.

Back to sediba's brains:

Berger and his team are at present still analyzing the "terabytes of data" from the X-ray synchrotron examination of the hominid remains. In the future, they hope to use this process to not only reveal further information about A. sediba, but also other fossils that they have found in South Africa.

Warren Dew wrote:

Steviepinhead wrote:Are you looking at the various news reports and blog discussions, or are you working off of the papers themselves?

I was primarily working from the blogs, including especially Hawks's. Based on that information, I looked at the similarities to Homo erectus (sensu lato). It looked to me like sediba was closer in the teeth and in the hips, and that contemporaneous habilis was closer in brain size and associated skull features and in limb proportions - to the extent we believe we have limb proportion data on habilis. If they are separate species, this implies convergent evolution in two major areas, either between erectus and sediba, or between erectus and habilis. I found that less likely than the specimens being in the same species with a certain amount of intraspecific morphological variation.

That's consistent with Donald Johanson's email that's quoted in this article:

http://cosmiclog.msnbc.msn.com/archive/ ... 60581.aspx

And in fact, Johanson previously discovered a fossil that sounds somewhat like sediba - with Homo dentition but Australopithecine body proportions - which he classified it as Homo erectus:

http://www.nature.com/nature/journal/v3 ... 205a0.html

However, on reading the "new species" sediba paper, I'm less impressed with the alleged hip similarities to erectus, and the dental features really seem to fall within the range of basically all Australopithecus and Homo except the robust Australopithecines. Ironically, reading the paper rather than just the blogs makes me more inclined to agree with the Hawks blog's view that sediba is really closest to Australopithecus Africanus. I am perhaps less charitable than he is about allowing those who make significant finds to be allowed to name their own species in the absence of otherwise convincing data, though.

I would note a couple of somewhat tangential things. First, the dental comparisons are a strong argument in favor of use of the Paranthropus genus for the robust prehuman hominins. Second, I agree with Berger that postcranial morphology is important and should play a part in classification. Third, I agree with Hawks that there's a big difference in a small amount of time between Australopithecus with the same roughly equal forelimb and hind limb lengths as Ardipithecus, and Homo erectus with much longer legs than arms, and that rapid change really needs to be explained. The relative dearth of postcranial remains for Homo habilis, in particular, needs to be addressed, and it's not clear to me that, if sediba is an australopithecine, Homo habilis even makes sense as species.

Though I'm not utterly unsympathetic to Au. habilis, there are more species, even in the early history of the genus Homo, than habilis and erectus. Whither ergaster, rhodesiensis, Dmansi, rudolfiensis, floresiensis, and others?

My takes are as follows. Ergaster is simply early Homo erectus.

Rhodesiensis, even if it is a separate species, is less than 500,000 years old and has no bearing on this discussion, which is about what happened around 2,000,000 years ago.

The Dmanisi georgicus find mostly serves to prove that the ranges of hominins extended well beyond Africa as of 1,800,000 years ago,

but the morphology doesn't seem markedly different from African specimens from similar dates as far as I know;

along with habilis and rudolfensis, it simply shows that there were creatures with brain sizes intermediate between Australopithecus and erectus, which we kind of knew anyway.

I'm convinced there are at least two or three more species names than actually distinguishable species here.

While floresiensis is certainly interesting, I don't know tht it has much relevance given how recent it is.

Steviepinhead wrote:Well, you're a lumper, not a splitter, that's for sure. Without getting more precise about the anatomical details and metrics, and comparing the fossils at that level of detail, much of this just seems impressionistic on your part.

The Dmanisi georgicus find mostly serves to prove that the ranges of hominins extended well beyond Africa as of 1,800,000 years ago,

Again, fair enough, as to the dating and the geological locus, though not all scholars would lump Dmansi in with erectus.

but the morphology doesn't seem markedly different from African specimens from similar dates as far as I know;

More impressionism.

While floresiensis is certainly interesting, I don't know tht it has much relevance given how recent it is.

The dated finds are recent, true, although the stone tools are very much older and, in any event, it is the branching or divergence date on the phylogenies which supports discussing floresiensis in with this ~2.000,000 lot of fossils, since floresiensis appears to have a suite of character traits which places it at or near this same cusp between australopithecine and earliest Homo.

I'd be happy to discuss more specifics on individual cases that people are interested in.

I don't find that argument conclusive yet, though. If floresiensis is descended from a late Australopithecine, I would expect to find others so descended in other locations far from Africa, for example in south Asia. Those finds may yet be made, but we haven't found them yet.

num1cubfn wrote:While I applaud this, I have two responses.

1)Everything is a link between some 2 other things, and

2)All this did was make two more "gaps".

Steviepinhead wrote:Warren Dew:

I'd be happy to discuss more specifics on individual cases that people are interested in.

It's beginning to look to me like we may be the last two standing who would be interested in that level of detail.

katja z wrote:

Steviepinhead wrote:Warren Dew:

I'd be happy to discuss more specifics on individual cases that people are interested in.

It's beginning to look to me like we may be the last two standing who would be interested in that level of detail.

You're not. It's just that some of us who are very interested aren't as well informed as you, so we limit ourselves to lurking and learning. But I can post some silly questions from time to time if that would make you feel less alone

Agrippina wrote:

katja z wrote:

Steviepinhead wrote:Warren Dew:

I'd be happy to discuss more specifics on individual cases that people are interested in.

It's beginning to look to me like we may be the last two standing who would be interested in that level of detail.

You're not. It's just that some of us who are very interested aren't as well informed as you, so we limit ourselves to lurking and learning. But I can post some silly questions from time to time if that would make you feel less alone

Yes I agree.

What i would like to see, is a simple, description of the various human species over time, without all the scientific jargon that i basically don't understand and don't have the time to learn. You two seem to seem to know what you're talking about so explain to it me nicely, the way that Steviepinhead explained the other thread to me, now I get what everybody's talking about i can ask intelligent questions instead of making knee-jerk reaction comments. Please do that, what were the first homonims? and where to from there to modern man.

The_Piper wrote::coffee:
I've been lurking this thread every day.

Agrippina wrote:

The_Piper wrote::coffee:
I've been lurking this thread every day.

It's very interesting. I hope that these scientists reveal more of their finds soon. They say they found a lot of skeletons there, so it will be fun. My son works quite closely with the university. The next time I'm in Joh'burg I'm going to ask him to take me to see them.