From what I understand, and I accept that I may be wrong, the reason for it's not being named 'homo' is because it's not an ancestor.

What gave you that impression?

I thought that the jaw / teeth were kind of like Homo, but the skull was more A. africanus. They went with Australopithecus due to the skull brain size. Sort of.

Tyrannical wrote:

From what I understand, and I accept that I may be wrong, the reason for it's not being named 'homo' is because it's not an ancestor.

What gave you that impression?

I thought that the jaw / teeth were kind of like Homo, but the skull was more A. africanus. They went with Australopithecus due to the skull brain size. Sort of.

Maybe the fact that I heard someone say that in reply to a question as to whether it was "The Missing Link."
Again of course I don't know what I'm talking about as usual, except i saw the press conference didn't I? Maybe I should've said "direct" ancestor, see what I marked in bold below:

These new fossils, however, represent a hominid that appeared approximately one million years later than Lucy, and their features imply that the transition from earlier hominids to the Homo genus occurred in very slow stages, with various Homo-like species emerging first."It is not possible to establish the precise phylogenetic position of Australopithecus sediba in relation to various species assigned to early Homo," wrote Lee Berger, a lead author of one of the Science reports. "We can conclude that… this new species shares more derived features with early Homo than any other known australopith species, and thus represents a candidate ancestor for the genus, or a sister group to a close ancestor that persisted for some time after the first appearance of Homo."Many scientists believe that the human genus Homo evolved from Australopithecus a little more than two million years ago—but the origin has been widely debated, with other experts proposing an evolution from the Kenyanthropus genus. This new Australopithecus sediba species might eventually clear up that debate, and help to reveal our direct human ancestors."Before this discovery, you could pretty much fit the entire record of fossils that are candidates for the origin of the genus Homo from this time period onto a small table. But, with the discovery of Australopithecus sediba and the wealth of fossils we've recovered—and are recovering—that has changed dramatically," Berger said.The name itself, "sediba," means "fountain" or "wellspring" in the seSotho language, spoken in South Africa, and indeed, researchers do believe that the new fossils will provide a wealth of information about our human origins.For now, these new hominid fossils make it clear that the evolutionary transition from small-bodied, and perhaps more tree-dwelling, ancestors to larger-bodied, full-striding bipeds occurred in gradual steps

Read the rest at Red Orbit

[youtube]http://www.youtube.com/watch?v=sBrgL_I6eto[/youtube]

That's weird i was under the impression that we WERE apes,did i miss something?

Eager non-theist wrote:That's weird i was under the impression that we WERE apes,did i miss something?

Yes, we are apes.

I thought we were Pan sapiens and chimps were Homo troglodytes

Darwinsbulldog wrote:I thought we were Pan sapiens and chimps were Homo troglodytes

What, i was just pointing out that the op's choice of title was terrible. I guess i should've worded the post differently.

RichardPrins was just copying and pasting the article with title, so he's not to blame.

However, the article is fucking terrible and it's a real shame that we have such an important find being reduced to discussion about absurdities because an unscholarly article was the first one posted on the board.

Check out my post here:
evolution/missing-link-between-man-and-apes-found-t4435-20.html#p118602

For some better resources on this find.

Very interesting, I've just heard that the scientists have asked SA's school children to come forward with names for the younger skeletons. Pretty cool that someone is going to go down in history as the person who named it.

Note that you don't have to be in the genus Homo to be a potential human ancestor: some population of eukaryote cells a billion years ago was the ancestor of all multicellular critters, some population of multicellulars was the ancestor of all fungi, plants, and animals, some very early non-bilaterian population of animals was the ancestor of all bilaterians, some early bilaterian population of worm-like critters was the ancestor of all invertebrates and vertebrates, some very early vertebrate was the ancestor of all jawless fish and cartaliginous fish and bony fish and tetrapods, some early population of lobefinned fish was the ancestor of all tetrapods, some early population of tetrapods was the ancestor of all amphibians, anapids, synapsids and diapsids, some early population of amniote was the ancestor of all synapsids and diapsids, some early population of synapsids was the ancestor of all therapsids and their proto-mammal relatives, including dimetrodons and the like, some early population of therapsids was the ancestor of all monotremes and metatherians/placental mammals, some early population of placental mammals was the ancestor of all marsupials and eutherians, some early population of eutherians was the ancestor of all modern mammals, including the primates, some early population of primates was the ancestor of all tarsiers, lemurs, Old World monkeys, and New World monkeys, some early population of Old World catarrhin primate was the ancestor of all Old World monkeys and , some early population of was the ancestor of all cercopithecines (baboon, macaques, etc.) and all apes, some early population of apes was the ancestor of all the gibbons and siamangs (lesser apes) and great apes, some early population of great apes (with a distribution across eurasia as well as africa) was the ancestor of the orangutans and all the African great apes, some Miocene African great ape -- Hominidae -- population was the ancestor of all gorillas, chimps, and humans (and their extinct relatives), some early population of arboreal apes --possibly already upright in posture, along the lines of Orrorin or Ardipithecus, though whether the branching point came before or after these specimens remains unclear -- gave rise to two subsequent populations of apes, one eventually specializing for vertical tree-climbing (the common chimps and bonobos) and one for terrestrial bipedality (the "ape-men," and ultimately anatomically modern humans).

From there the picture gets increasingly controversial, not because we have too few fossils of potential ancestors and relatives, but because we already have so many. Here for example, is one of two recently-proposed phylogenetic charts for H. floresiensis ("hobbits"):

Note that most of the species with the H. (Homo) prefix branch off without giving rise to H. sapiens.

The discovers of the Au. sediba fossil material have included a proposed phylogenetic chart in their supplementary materials to the descriptive papers (hat tip to a comment by blogger afarensis fcd on laelap's blog): it's a pdf so I can't easily extract the phylogenetic chart to present it here, but you can find it by going to the open-access pdf and scrolling down -- hold the presses! I found one I can present, hat tip to the Three Pound Monkey Brain blog --

Note that the hobbits aren't shown on the sediba phylogeny, but that the branching pattern is otherwise roughly similar. Again, the pertinent point is that most of the Homo species, ergaster, habilis, dmanisi, rudolfensis, etc., do NOT lead to the sapiens line. They shared a common ancestral population that branched, and branched again, and branched again, with most of the branches going extinct, but with one series of branch, branchlet, twig ... leading to us.

The debate going on in the Multiregional thread is what happens further down the sequence of branches, as we get to the migrations of some of these Homo species out of Africa (image from the Atavism blog, with yet another tip of the hat, discussing the possible significance of the X-woman mitochodrial DNA analysis found in the Denisova cave in Siberia) :

The multiregionalists are arguing that these various waves of Out of Africa migrations (and the hobbit migration could also be included, with the hobbits themselves, like sediba, arguably occupying a phylogenetic position very close to the Au. => Homo transition) did not preclude gene flow among the various Homo populations in and out of Africa. The Out of Africa proponents are arguing that, once again, the various populations diverged genetically such that H. ergaster, H. erectus, "H. denisova" (no, the researchers have not yet gone far enough to designate that mitochondrial lineage as a separate species, pending nuclear DNA analysis, though they are heavily hinting), and H. neanderthalis represented separate branching points, past which there was no significant gene flow among these (which everybody accepts) highly-related species.

Hey Steviepinhead, thank you for posting that, it's very informative.

Have you ummmm, been in a cave the last few days?

Aw, shucks...

Like most of us, I hope, I'm just trying to get on top of this for myself.

I find if I can put it together well enough that it helps others, I must be getting a little closer to being able to explain it to myself.

These recent cladistic analyses have their critics, of course (which characters were used, how were they weighted, is there sufficient contrast between them or do they lie closely along a continuously-varying range, how adequate were they for some of the more fragmentary fossils -- thankfully, we now have many fossils like these that are far from fragmentary, though of course even fragments can provide critical data in a context as rich as our fossil ancestry now is -- and what precautions were taken to make sure that the software that sorts the data is finding the likeliest fit, as opposed to responding to confounding factors, such as the infamous Long Branch Attraction...), but I find them interesting in part just because -- when done right -- they should be "blind" to scientists' intuitive response to the fossil material and to their personal preferences as to species and genus assignment.

And one of the interesting things about this find is that, even as it makes the "conservative" choice to retain this "mosaic" fossil in Australopithicus, despite the obvious inclination of the scientists to see sediba as a transitional "bridge" from Au. to Homo (even as they reject the "missing link" thinking), it results in a phylogeny that moves some of the previously-found material from Homo to Au., or the reverse.

Again, done right -- and there's the rub -- I would prefer to see the branch points on the phylogeny that's supported by the individual characters across all the relevant fossils, regardless of the genus and species attributions. While the pretty, color-coded "flow charts" we see, where australopithecus vaguely "flows" into early Homo which vaguely flows from erectus and antecessor and Heidelbergensis and rhodesiensis or whatever "into" H. sapiens are impressionisticly attractive and tidy, and certainly have their uses, they don't seem to me to convey the same degree of information about actual characters as precisely as a good, well-researched and exhaustively analyzed phylogenetic chart.

Fortunately, more and more of the relevant measurements and photographs and 3-D scans are becoming available to all the scientists involved, the weighting assumptions behind the analytic software is being presented transparently (and being critiqued independently of individual phylogenetic results in given areas of paleontological research), and -- with the addition of spectacular new finds like these -- the material being analyzed just gets richer and richer.

The result, of course, is going to be that each new find jostles the phylogenetics around, and re-arranges the "branching pattern" of the bush.

It's looking to me, though, that a certain consistency is starting to emerge from the data. Not a perfect consistency, and not an immutable "correct" evolutionary tree, but one which is fairly well-anchored in at least its broad outlines.

Moving some of the "transitional" fossils from one side of the (illusory) Au.-Homo divide to the other will certainly continue, as will moving a given fossil from one nearby twig to another.

Heck, that's half the fun!

Yep, a little like when you're building a family tree and you find relatives you didn't know you had.

My inclination is always to tidy things up, and have them properly arranged. It would be nice to see a line of evolution from the first guy to modern man so that the creation story can finally be laid to rest.

And this gets into our realistic expectations for what science -- and scientists -- can actually deliver.

Amazing stuff, obviously. Far more than the "supernatural" alternatives, in any remotely-practical sense.

But still. I have a second cousin who is researching our family tree. Good guy, we grew up in the same town, solid as a rock, extremely diligent, as motivated and dedicated to detail and getting down to the actual facts, not what he would "like" them to be, as any scientist could be. Visits isolated gravesites, interviews aging family members, collects relevant photographs from the entire family, cross-checks all his info with all the other possible sources, combs through all the available online and municipal and census and military and court and whatever records. And STILL, only three or four or five generations back, he runs into dead ends, quandaries, unresolvable questions. If we assume this one little connection, that cannot be adequately documented, then we can "attach" our little family tree to bigger well-researched ones that go back further... But IS that assumption a fair and valid and consilient one to make?

This is, in small compass, the same question that historians and paleotologists and evolutionary biologists and geologists and even cosmologists run into, in attempting to reconstruct the past. Some things, at some level of detail, are just lost forever. I can't confirm even important past details of what I think I remember from my own life, where I have had -- for the most part -- the best possible position to be the one in the know. How much harder it is to wind life after life, story after story, lineage after lineage, community and polity and populace, into the BIG overall metastory of history, humanity, and life on earth, storyline of the cosmos itself?

The people who dedicate themselves to using the best evidence available, to making the fewest assumptions possible, to getting the facts straight even above their own personal, family, religious, community, and cultural myths and certainties, these people have my deepest and most profound admiration.

Even if I do my best to cross-check and be skeptical of their findings and conclusions.

Steviepinhead wrote:Again, done right -- and there's the rub -- I would prefer to see the branch points on the phylogeny that's supported by the individual characters across all the relevant fossils, regardless of the genus and species attributions. While the pretty, color-coded "flow charts" we see, where australopithecus vaguely "flows" into early Homo which vaguely flows from erectus and antecessor and Heidelbergensis and rhodesiensis or whatever "into" H. sapiens are impressionisticly attractive and tidy, and certainly have their uses, they don't seem to me to convey the same degree of information about actual characters as precisely as a good, well-researched and exhaustively analyzed phylogenetic chart.

The issue with this is that a traditional phylogenetic chart, while great for tracking asexual evolution, becomes inaccurate at some level of detail for sexual evolution where an individual may have parentage from more than one line. That level of detail may have been reached here.

I haven't seen a strong argument yet for why this specimen isn't just a specimen of Homo habilis. Sure, it is different from previous habilis fossils in various details, but given that it is more like Homo erectus in some of those details, and less like it in others, it seems to me the simplest chart would put both this specimen and Homo habilis in a single, somewhat diverse species.

I do think it makes it look like the right thing to do is reclassify habilis as Australopithecine, and start the Homo genus with Homo erectus.

Warren Dew wrote:

Steviepinhead wrote:Again, done right -- and there's the rub -- I would prefer to see the branch points on the phylogeny that's supported by the individual characters across all the relevant fossils, regardless of the genus and species attributions. While the pretty, color-coded "flow charts" we see, where australopithecus vaguely "flows" into early Homo which vaguely flows from erectus and antecessor and Heidelbergensis and rhodesiensis or whatever "into" H. sapiens are impressionisticly attractive and tidy, and certainly have their uses, they don't seem to me to convey the same degree of information about actual characters as precisely as a good, well-researched and exhaustively analyzed phylogenetic chart.

The issue with this is that a traditional phylogenetic chart, while great for tracking asexual evolution, becomes inaccurate at some level of detail for sexual evolution where an individual may have parentage from more than one line.

You've provided some support for this in the discussion on the Out of Africa thread, in terms of both genetics and morphology. On what details of morphology -- since molecular genetics are beyond our grasp in this instance -- are you relying in your discussion of Au. sediba. The open access paper of Lee Berger is loaded with that level of detail. Which of those details supports your extension of your point to these fossils?

That level of detail may have been reached here.

How so? Can you tell us more than your individual impression?

I haven't seen a strong argument yet for why this specimen isn't just a specimen of Homo habilis.

Are you looking at the various news reports and blog discussions, or are you working off of the papers themselves? The principal reasons given by the discoverers, though they give many more, are the overall Au. body proportions (longer arms and shorter legs), the small cranial capacity, and the feet, which are not yet Homo feet, and thus don't imply the full striding bipedality of Homo. As John Hawks shows very well, many of the features of the face and jaw are stikingly like earlier Au. africanus specimens found close by to these. While it's an arguable close call, the overall morphology, locomotion, and facio-cranial features lean toward Au., while some hip, upper femur, and aspects of dentition lean toward Homo. Not to mention that the phylogeny leaned toward a pre-Homo branching from Au.
But everybody recognizes that it's a mosaic, a patchwork of retained Au. and derived Homo features. That's the fun thing about these fossils: whether they can ever be shown to be direct ancestors or not, they are right on the cusp. Just demonstrating that there is such a close case demolishes the denialist position and validates evolutionary expectations.

Sure, it is different from previous habilis fossils in various details, but given that it is more like Homo erectus in some of those details, and less like it in others, it seems to me the simplest chart would put both this specimen and Homo habilis in a single, somewhat diverse species.

There may be a case to be made for that, but you have neither made it, nor linked to where you think that case has been persuasively made. John Hawks and Tim White, no slouches in this area, have made more or less explicit cases that these specimens fall instead into the range of variation for Au. africanus.

I do think it makes it look like the right thing to do is reclassify habilis as Australopithecine, and start the Homo genus with Homo erectus.

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? Whither the site/number specimens that, in Berger et al.'s phylogenetic analysis, fall either side of Au. sedabi, without yet having a secure "consensus" home in either genus?

That's why, in some ways, a well-laid out phylogeny tells you more than some pick'em, eh, could go here, could go there, attribution to one genus or the other. The genus is an artifact; the entire suite of morphological characteristics which go into a well-grounded phylogeny are first-level data, subjected to a cluster analysis...

Frankly, at this stage of matters, my view is we get better information, and a better idea of the history of branching populations, via the latter sort of data analysis than through the former sort of semantics.

But that could just be me.

i hate the term 'missing link'

wunksta wrote:i hate the term 'missing link'

It's wrong on so many levels.

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.