Australopithecus sediba Voted Off the Island

This does not surprise me.  Science Magazine has a short story which suggests strongly that the characteristics in Au. sediba render it unsuitable for a possible ancestor to the genus Homo. 

With its fossils dated to 1.98 million years ago, Au. sediba is too young to be directly ancestral to all members of the genus Homo. But Berger and his colleagues proposed in 2010, and again in 2013 in six papers in Science, that given the many humanlike traits in Au. sediba’s face, teeth, and body, the Malapa fossils were a better candidate than Lucy or other East African fossils to be ancestral to Homo erectus, a direct human ancestor that appeared 1.8 million years ago.

In a talk here, though, paleoanthropologist Bill Kimbel of Arizona State University in Tempe analyzed the most complete skull of Au. sediba and systematically shot down the features claimed to link it to early Homo. Kimbel noted that the skull was that of a juvenile—a “7th grader”—whose face and skull were still developing. In his analysis, with paleoanthropologist Yoel Rak of Tel Aviv University in Israel, he concluded that the child already showed traits that linked it most closely to the South African australopithecine Au. africanus, a species that lived in South Africa 3 million to 2.3 million years ago. And had it survived to adulthood, its humanlike facial traits would have changed to become even more like those of Au. africanus.

For example, the breadth of the young Au. sediba’s cheekbones appears narrow, as in early Homo. But by studying other australopithecine, ape, and Homo fossils to see how features of the cheekbones change as individuals grow and chewing muscles develop, Kimbel and Rak could predict how the boy’s face and skull would have looked if he’d grown up to be an adult. The resemblance to Au. africanus is so striking, in fact, that Kimbel thinks Au. sediba is a closely related “sister species” of Au. africanus—and not a long-lost human relative. “We don’t believe … that Au. sediba has a unique relationship to the genus Homo,” says Kimbel.

At this point, it is pretty hard to tell where a precursor might be found. We know that there was considerable variability in australopithecines throughout the Plio-Pleistocene but, as of yet, no good candidate has arisen.What seems to be clear, however, is that there is a general trend toward more modern morphology in the pelvis and hands, as exhibited by Au. sediba.  Whether or not these characteristics are present in other specimens of Au. sediba is, however, unknown.  As Kimbel notes, we need an adult one to see for sure. 

One Reason Palaeoanthropology Is So Hard

The Star, from South Africa has a nice story on a hunk of rock that contains the second of the skeletons pulled from the South African cave site of Malapa, the first of which was the nice juvenile Australopithecus sediba individual. Shaun Smillie writes:

Last night, in Shanghai, China, scientists from Wits University’s Institute for Human Evolution announced the discovery of fossils buried deep in a piece of rock about a metre in diameter. They are believed to be the remains of Karabo, one of the two Australopithecus sediba skeletons that were discovered at Malapa, in the Cradle of Humankind, in 2009.

Karabo’s partial skeleton was removed from the Malapa site, but the rock appears to contain more of his bones.

One is reminded of the arduous task that awaited Raymond Dart as he sat before the stone breccia that contained the first australopithecine to be discovered in South Africa. It took him seventy three days to pry apart the limestone to extract the remains.

This is something that is often missed by the popular press and creationists: fossils are rare and complete fossils are even rarer. And, unlike the kind of archaeological work that goes on in neolithic or bronze age sites, human fossil remains are usually found in concretions—limestone or some other hard rock—and are very hard to extricate cleanly. In the case of Ardipithecus ramidus (or “Ardi”), the extraction took years because the bones were so brittle. Jamie Shreeve writes in National Geographic that as soon as bones were removed, they were doused with hardener to make sure they did not fall apart. Then, once they are removed comes the equally arduous task of trying to reconstitute the pieces. Complete skulls are rare and even the most complete ones have to be put back together. Once we have them, they are great tools for discovering how we came to be and the stages that got us here. But it takes a lot of work just to get to that point. It will be nice when we get the second A. sediba skeleton out to see how it compares to the one we already have.

The Diet of Australopithecus sediba

There is some suspicion that Australopithecus sediba, discovered by Lee Berger (or, rather, his son) may be on the line that eventually leads to Homo. This is not clear but right now, it is as good as any model we have. We now know a bit more about what Au. sediba ate. According to Science Daily:

Australopithecus sediba, believed to be an early relative of modern-day humans, enjoyed a diet of leaves, fruits, nuts, and bark, which meant they probably lived in a more wooded environment than is generally thought, a surprising find published in the current issue of Nature magazine by an international team of researchers that includes a Texas A&M University anthropologist.¹

The goofy thing is that these hominins (or at least the ones we have) ate much more of these kinds of items than any other hominin we have discovered. In fact, their diet is much more like that of a chimpanzee than a hominin. This probably means nothing more than that is what they had access to but it does mean they were having a diet different from the robusts. Au. sediba’s teeth are gracile, in comparison to those of the robusts or earlier australopiths. It was definitely a forested environment.

¹Amanda G. Henry, Peter S. Ungar, Benjamin H. Passey, Matt Sponheimer, Lloyd Rossouw, Marion Bamford, Paul Sandberg, Darryl J. de Ruiter, Lee Berger. The diet of Australopithecus sediba. Nature, 2012;
DOI: http://dx.doi.org/10.1038/nature11185

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Nature News Story on Au. sediba

Nature News has a story on the Australopithecus sediba skeleton described by Lee Berger and colleagues.  Ewen Callaway writes:

At around 420 cubic centimetres, A. sediba 's puny brain compares to those of other Australopithecus specimens and chimpanzees. But a high-resolution synchrotron scan of the brain's impression on the skull shows enlarged frontal areas that are normally associated with humans and linked to higher cognitive abilities, such as planning. A. sediba's pelvis also looks wider than those of other australopiths, raising doubts about the idea that the human pelvic shape evolved to accommodate large-brained babies. "Whatever is driving a relatively human-like shape of the pelvis, it is not a big brain," says Berger. The orientations of its leg and ankle bones suggest that A. sediba walked upright, and its nearly complete ankle resembles that of a human. But its long arms, and some features of its feet and shin bones, are similar to those of a chimpanzee. Taken together, these features suggest that A. sediba was adapted for both bipedalism and tree-dwelling.

This is a wonderful mosaic. As I wrote yesterday, though, it is not clear where it fits. There are three possibilities: A. africanus gives rise to A. sediba and A. habilis and A. rudolfensis.  Here, the two species of early Homo have been demoted and all three have transitional characteristics that represent a general trend toward modernity (after Walker and Wood).

The second scheme has A. africanus giving rise to A. sediba, which then goes extinct, and H. habilis and H. rudolfensis (in some fashion), one of which then gives rise to H. ergaster.  This posits that the traits present in both early Homo and A. sediba represent a general trend toward modernity. 

 

The third scheme has  A. garhi giving rise to early Homo with A. africanus giving rise to A. sediba, which then goes extinct.  The advantage of this is that A. garhi has modern-like limb proportions and is found in northeast Africa, not far from early Homo, while A. africanus and A. sediba are both found in south Africa.

 

Which one of these is right?  Are any of them right?  Who knows.  What we do know is that these critters have relationships to each other in some way, shape or form.  

More on Au. sediba From CNN

CNN has a story on Australopithecus sediba with some better pictures.

Au. sediba Now Considered Possible Ancestor to Homo

New research is suggesting that the overall anatomy of Australopithecus sediba makes it the best candidate for being ancestral to Homo.  The article in Science Daily is quite long and delves into the specific traits that Lee Berger suggests are thought to evolving in the direction of Homo.  They write:

Lee Berger, the project leader from the University of the Witwatersrand in Johannesburg, South Africa, explains what these new findings mean for modern humans. "The many advanced features found in the brain and body, along with the earlier date, make it possibly the best candidate ancestor for our genus -- the genus Homo -- more so than previous discoveries, such as Homo habilis"
The age of the Au. sediba fossils has been constrained to about 1.977 million years, which predates the earliest appearances of Homo-specific traits in the fossil record. Until now, fossils dated to 1.90 million years ago -- and mostly attributed to Homo habilis and Homo rudolfensis -- have been considered ancestral to Homo erectus, the earliest undisputed human ancestor. But, the older age of these Au. sediba fossils raises the possibility of a separate, older lineage from which Homo erectus may have evolved.

This position seemed odd to me at first because there is already evidence of “early Homo” dating back to 2.3 million years ago. Then it occurred to me that this article makes a tacit assumption that is not stated: Homo habilis and Homo rudolfensis are not really Homo, but are Australopithecus. This is an argument that has been made by Alan Walker and Bernard Wood who suggest that, despite the size differential between H. rudolfensis and the late australopithecines, they are more similar than different.This levels the playing field and then Au. sediba simply becomes the branch of Australopithecus from which Homo sprung.

Taxonomy is a black art and we run the risk of tying too much significance to our taxonomic designations.  If we argue that Au. sediba gave rise to H. ergaster, despite the fact that there are already two species of Homo running around, it conjures up ideas of convergent evolution where an earlier australopithecine gave rise to Homo habilis and Au. sediba gave rise to Homo ergaster.  If, however we demote earliest Homo down to australopithecine status, the difficulties vanish “like the snows of yesteryear” as Isaac Asimov would say.  Look for this to be challenged as well. 

Lee Berger on Australopithecus sediba

Daily Web Day has a story on Lee Berger's comments at the recent American Association of Physical Anthropologists' convention. The author writes:

The researchers said that the hominin shows some surprisingly modern traits and its species may even be an ancestor of our own genus.

“We really have found something very, very odd and very unexpected,” Science Now quoted discovery team leader Lee Berger of the University of the Witwatersrand in Johannesburg, South Africa, as saying.

But other paleoanthropologists are waiting for more detailed analysis of the still-unpublished fossils before they agree on its identity or place in the human family tree.

According to new dates reported by Berger in his talk at the annual meeting of the American Association of Physical Anthropologists (AAPA), the four hominin individuals died when they fell into a “death trap” in a cave about 2 million years ago at Malapa, South Africa.

The growing concensus is that A. sediba shows up just after the appearance of Homo but that it may have been on a line that gave rise to the genus Homo. The curious thing is that there is scant evidence of Homo in South Africa but quite a bit in East Africa. In East Africa, however, there are only robust australopithecines that overlap with early Homo for a good 800,000 years. I will side with those that want more evidence first.

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Hominid Discoveries: Google Earth Helps Out

Apparently, subsequent to the recent discovery of Australopithecus sediba, Lee Berger used Google Earth to help map undiscovered caves in the vicinity of the find. As detailed on Mashable, here is a Google Video detailing the collaboration.



Cool.


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Acts and Fiction: The ICR Tackles Australopithecus sediba

Brian Thomas of the ICR has a take on Australopthecus sediba in the recent news section of their web page. It doesn't start out well:

Evolution's search for the "missing link" between man and ape has a long and troubled history. Australopithecus sediba is the latest fossil find that is claimed to represent evolutionary human ancestors. But the remains of this extinct ape provide several solid clues that contradict any evolutionary relationship to man.

First, the remains were dated at 1.9 million years, which is at least one million years younger than evolutionary ages assigned to some fully human remains.1 If Au. sediba really were an ancestor to man, then its kind would have morphed into mankind and ought therefore not exist (as man's ancestor) after mankind had already arrived on the scene.2 Fossil ages from both species overlap considerably according to standard dates, thus failing to line up chronologically with an evolutionary scenario.

Well, first, evolution has never searched for the "missing link" of anything. There is no applicable concept in evolutionary biology for the concept since it is biologically meaningless. If Thomas has only read the popular press, he probably would have picked up on this term. It doesn't shows up in any of the Science papers on A. sediba, which one would hope Mr. Thomas has read.

The rest is just nonsense. He doesn't define what he means by "fully human." Therefore, one can only guess which hominids he is referring to. If he is referring to modern humans, he is 900 000 years off the mark. If he is referring to Homo erectus/ergaster, his timing is right but these remains aren't fully human by any stretch of the imagination. Even a cursory glance at these remains reveals this. It is therefore, not possible for A. sediba to "morph onto the scene" after the appearance of modern humans since even Homo erectus wasn't around at this point.

Additionally, how does the fact that the species overlap fail to "line up chronologically with an evolutionary scenario?" This is only true if one holds a strictly unilineal, vertical view of evolution, one that wasn't held even by Darwin. Such a view reflects a complete lack of either understanding or education in evolutionary theory by Mr. Thomas, suggesting he is not remotely qualified to write this essay.

He then completely misquotes Bill Jungers and his analysis of Ardipithecus. Thomas writes:

Just a few months ago, anthropologist C. Owen Lovejoy promoted Ardi as an ape who walked upright. But to William Jungers of Stony Brook University Medical Center--who, like the rest of the world, was only able to review the evidence after Ardi had already been proclaimed a walker in the publication of its initial study--the reconstructed skeleton "really doesn't show any adaptations for bipedalism at all."

What Jungers was actually quoted as saying was this:

None of the known foot components, no matter how well adapted to climbing, preclude Ardipithecus from walking upright on the ground. Jungers, however, thinks "it really doesn't show any adaptations for bipedalism at all." In fact, he says, many components of Ar. ramidus don't make Ardi look that much more adept at walking upright than chimpanzees—a primate that White et al. disavow as a model for early human evolution. In a summary paper led by Lovejoy, the authors describe Ardipithecus as a "facultative upright walker," one that can walk on two legs if needed (to carry something in the forearms, for example) but that isn't necessarily prone to do so. (emphasis mine)

Jungers wasn't talking about the skeletal reconstruction, he was talking about only the foot. He further indicates that, while he does not accept all of the evidence for bipedalism in Ardipithecus, he agrees that it would have been more bipedal than a chimpanzee.

Thomas then completely misreads the account of Berger's search for taphonomic data to understand how A. sediba died and to see if there is any residue of an endocast. Here is what Thomas writes:

For such soft samples as brains and insect eggs to have been preserved for thousands of years would be "special" enough, considering how quickly such organic materials decay. But to expect someone to believe that brain tissue escaped decay for 1.9 million years is asking far too much. It would be like expecting someone to believe that Au. sediba was man's ancestor--even though its skeleton was entirely ape-like and it supposedly lived long after its own descendants.

What Thomas doesn't seem to understand here is that Berger is looking for fossilized remains. Throughout hominid palaeoanthropological research, numerous brain endocasts have been found. In fact, one was recovered with the first australopithecine found, in 1924. Along with the face and a partial skull-cap, the fossilized brain of Australopithecus africanus was presented to Raymond Dart at the University of Witwatersrand. Immediately, he recognized that he was not looking at a run-of-the-mill primate but, rather, one that had human traits. This, and other discoveries, have led researchers to reconstruct how the brains of these early hominids differed from those of later ones. In fact, it has given rise to one of the most celebrated disagreements in palaeoanthropology, that between Dean Falk and Ralph Holloway, about just exactly how modern the brains of australopithecines were.

Thomas is completely unaware of this. Consequently, his comments are not just uninformed, they are ridiculous. The ICR's writers, once again, demonstrate that they are simply unwilling or unable to comprehend basic science.

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The Christian Post on Australopithecus sediba

Eric Young of The Christian Post has an article on their site addressing Australopithecus sediba. The article is very quick to land on the popular press for some misinformation. He writes:

Two fossils that were discovered in South Africa nearly two years ago are causing a stir today after two articles published recently in the journal Science introduced them as members of a new species that “might help reveal the ancestor” of the genus Homo. While some – mostly media – have been quick to hail the species as the “missing link,” many more have cast their doubts over the discovery, which some say might not even be a new species.

Some critics further say the find expands the cloud of uncertainty rather than “cast new light,” as Science claimed in its introduction of the papers.

It is unfortunate that scientists cannot disabuse the popular media of the term "missing link" which has no biological reality whatever. Its use then forces scientists to explain what a particular find really means. This "backpeddling" gives ammunition to those who would suggest that evolution does not occur or that palaeontologists do not know what they are doing. Neither is the case.

While not having much new information, the article is reasonably fair in portraying the views of both the YEC and evolutionary biologists' sides.

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Carl Zimmer on Australopithecus sediba

Carl Zimmer of Slate has an article on the hoopla surrounding A. sediba's discovery as well as all of the other discoveries that manage to galvanize the public's attention and promote some misinformation in the process. He writes:

Whenever scientists make a major discovery about human evolution, we get treated to a lot of misconceptions. The most popular of them all is the myth of the missing link—the idea that paleontologists are on an eternal quest for ancestors linking us directly back to earlier forms of life. Last May, for example, scientists reported the discovery of a 47-million-year-old fossil of a primate called Darwinius. "Fossil is evolution's 'missing link,' " blared a headline in the Sun."The beautifully preserved remains—dubbed Ida—is believed to be a direct connection between humans and the rest of the animal kingdom," the article said—a sentence that makes no sense the first time you read it and then somehow manages to make even less sense the longer you look at it.

At the heart of the article is the concept of collateral ancestry as opposed to unilineal ancestry. It is the second that gives rise to the term "missing link." Such a term is ludicrous in light of what we know of how evolution proceeds. Collateral ancestry is where different related species share derived traits relative to their ancestors. An example of this would be feathers in dinosaurs and early birds. Feathers appeared in dinosaurs, likely, for insulation initially. Some of these dinosaurs went extinct but at least one branch kept evolving. This branch then, perhaps, split into two or more branches, one of which became birds. That is very simplistic but you get the idea.

It is likely that this sort of thing happened in human evolution as well, with several sister species being on the landscape at the same time, one of which gave rise to later hominids. As Berger notes, A. sediba may not be ancestral to later hominids at all. Zimmer concludes:

But that's OK. Even if A. sediba doesn't turn out to be a close relative, it gives us a glimpse at the remarkable diversity of hominins that walked the Earth 1.8 million years ago. And no matter which hypothesis wins out, A. sediba is evidence that these are exciting times to study human evolution.

He is absolutely correct about that.

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Casey Luskin on The Smithsonian Human Origins Exhibit

Casey Luskin has an article on Evolution, News & Views on the Smithsonian exhibit called "What Does It Mean To Be Human?" Luskin addresses the standard creationist argument that gaps in the fossil record disprove evolution. He quotes from the educator's guide, which reads:

Misconception: Gaps in the fossil record disprove evolution.

Response: Science actually predicts gaps in the fossil record. Many species leave no fossils at all, and the environmental conditions for forming good fossils are not common. The chance of any individual organism becoming fossilized is incredibly small. Nevertheless, new fossils are constantly being discovered. These include many transitional fossils—e.g., intermediary fossils between birds and dinosaurs, and between humans and our primate ancestors. Our lack of knowledge about certain parts of the fossil record does not disprove evolution.

Luskin responds:

Did you get that? Ignoring the fact that transitional fossils are often missing even among taxa whose records are very complete, now Darwin’s defenders argue that their theory “predicts gaps in the fossil record.” How convenient!

This is a semantic trick. It is the same as saying Black Holes don't exist because we cannot see them. Such a statement completely overlooks the fact that there is a very large amount of evidence, based on how astronomical bodies behave under the influence of strong gravimetric forces, that, yes indeed, Black Holes do exist. I would venture to guess that very few professional astronomers doubt the existence of Black Holes.

Because we are missing sections of the fossil record, even large sections of the fossil record overtrivializes the fact that we do have very good fossils to work with and almost unbroken sequences of fossils of many different orders. Luskin, in fact, ignores the second part of the paragraph that he quotes.

That we have gaps is unavoidable. Evolutionary theory doesn't predict gaps. Geology predicts gaps. There is simply no way short of a miracle that we would have completely fossil rich preservation sites for every conceivable depositional environment. Such an expectation misunderstands how geological processes work. Expecting such a fossilized environment misunderstands how taphonomy works. Luskin continues:

What's ironic, however, is that if you ask the question How Do We Know Humans Evolved? the answer you’re given is, “Fossils like the ones shown in our Human Fossils Gallery provide evidence that modern humans evolved from earlier humans.” So whether you find fossils or you don’t, that’s evidence for evolution.

Here's irony for you. The human fossil record, in fact, is replete with transitional forms. Here are a few:

• The recently discovered and described Ardipithecus shows the transition to from a quadupedal gait to bipedalism.
  
• The material from Hadar and Laetoli show more advanced bipedalism relative to Ardipithecus in A. afarensis, which still possesses slightly curved fingers to grasp limbs, indicating that some time was still spent in the trees.
  
• A. afarensis also shows remarkable features in the face that are exactly intermediate between apes and later humans.
• There is a flurry of different australopithecine forms between 3.5 and 2.0 million years ago, some robust, some gracile. All are related and yet are different, showing regional variation and change through time.
  
• The remains attributable Homo habilis, whether they be one species or many, show brain expansion on a basically australopithecine face (this is especially true with KNM-ER1470).
  
• There is a remarkable series of gradations from what is considered Homo habilis to what is considered Homo erectus or Homo ergaster. There is disagreement about how many species are represented because the material is quite variable—and shows considerable change over time. This is also why we are having trouble figuring out which group early Homo came from.
  
• There is considerable disagreement about when Homo erectus ends and archaic Homo sapiens begins due to the transitional nature of much of this material. This has led some, such as Milford Wolpoff, to suggest sinking H. erectus into the Homo sapiens line, arguing that it represents one long lineage.
  
• It is also clear that some traits persist in some populations longer than others. Homo antecessor, from Spain, shows incipient archaic Homo sapiens characteristics at 800 000 years ago, while over in Germany, the Mauer mandible from Heidelberg, still shows H. erectus traits.
• Over in China, Homo erectus (Zhoukoudian, Hexian) persists until around 250 000 years ago, while at 200 000, obvious changes have occurred in the face (Dali, Maba) in the Homo sapiens direction.
• Modern human traits do not appear all at once, but rather over a period of 60 to 80 000 years in Africa (Herto, Klasies River Mouth, Border Cave) and the Near East (Mugharet-es Skhul, Jebel Qafzeh). Early "modern" specimens still show a mix of archaic and modern features
  

I could go on for pages and pages. The point is that, despite the fact that we have gaps in the fossil record, what we do have is good enough to make some pretty dang good assessments of what happened in the past. The human fossil record is a wealth of information about our history as a species. To dismiss it out of hand because there are gaps is simplistic at best and ignorant at worst. He ends by quoting the great evolutionary biologist Ernst Mayr, who passed away a few years ago:

But the exhibit gives no evidence of dissent from the official party line, such as an admission from Ernst Mayr in 2004 that "[t]he earliest fossils of Homo, Homo rudolfensis and Homo erectus, are separated from Australopithecus by a large, unbridged gap,” and therefore we’re in a position of “[n]ot having any fossils that can serve as missing links."

Mayr was a brilliant evolutionary biologist but he did not work in the human fossil record. He is incorrect about his assessment. There are fossils of all shapes and sizes between the late australopithecines and Homo erectus. The problem is that there is no agreement about what they represent. It is, nonetheless, not an unbridged gap. Finds like Australopithecus sediba help to bridge that gap. Maybe it is not a direct ancestor to early Homo. It still show the progression toward the Homo line in one of these late australopithecines.

The fact that there are gaps in the fossil record has nothing to do with the fact that evolution has or has not taken place. How does Mr. Luskin explain the areas where there aren't gaps?

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Australopithecus sediba Articles in Science

The Science Magazine articles on A. sediba are out. They are free for the time being. You just have to register at the site. The two articles cover the morphology of the finds as well as the geology of the Malapa Cave, in which they were found.
There is an extensive list of traits listed of both the cranium and face tabulated along with the other australopithecine species and early Homo. According to Berger and his team, it tells us the following:

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 (Table 1). Nevertheless, Au. sediba can be readily differentiated from Au. africanus on both craniodental and postcranial evidence.

The face has the scooped appearance of australopithecines, with nice anterior pillars and the cranium is small, with a size of about 420 cubic centimeters. For reference, our heads are around 1400 cubic centimeters in size. On the Homo side, however, the vault is expanded and the face is considerably narrower than that of your average australopith. Compare it to this front shot of Australopithecus boisei specimen OH5, taken by David Brill. This lateral flaring of the cheeks is characteristic of all australopithecines to one degree or another and is not found in early Homo at all.

From the neck down, the skull has a mix of australopithecine and early Homo traits. The australopithecine traits include comparatively long arms, a somewhat conical-shaped rib cage and a small stature. On the other hand, it has a pelvic structure much more like later Homo, suggesting even better walking and running abilities.

Berger and his team have, I think, correctly placed this critter in the genus Australopithecus, but it clearly does have some characteristics that presage early Homo. What those mean is not yet clear but there was a general shift toward more modern characteristics in all of these hominids at around 2 million years ago.

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CNN Story on Australopithecus sediba

CNN has a story on the new hominid, complete with picture, which is now tentatively being called Australopithecus sediba. It is truly remarkable, with obvious characteristics of early Homo and yet what appear to be some nifty-looking anterior pillars. Here is the image that appears on the CNN site. Until we get a full description, what this find appears to represent is a very primitive Homo with some australopithecine facial characteristics and some Homo facial characteristics along with a slightly expanded cranium. This pattern is later seen in specimens like KNM ER-1470, Richard Leakey's famous find in 1972.

Here's the problem. As I mentioned in the first post about this find, if you are familiar with the facial skeleton of the gracile australopithecines, you can see those characteristics in this specimen. If you are familiar with the facial skeletons of the specimens attributed to Homo habilis, you can see some of those characteristics as well. The fact that this specimen has both is a big deal. That Anika Smith can dismiss it out of hand strongly suggests that she doesn't have the background to understand what she is looking at.

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