Possible new human branch discovered?

[Ara Pacis]

I heard they found another skull with the same size. Some argued that it was statistically improbably to have two microcephalic individuals in the same area. I suppose one argument could be that the type of microcephaly these individuals had was genetic and possibly hereditary (proof of evolution?). Another argument could be that the microcephaly was rare and scattered in time and space but that the normal humans gathered them together in that location (in space, if not time) for some reason.

[ToSeek]

Long blog entry that covers a lot of the issues:

Is this the end for Homo floresiensis?

So, is this the end for Homo floresiensis? I'm sure it won't be. But there are some things that I hope will come to an end.


First of all, it is now abundantly clear that some kind of microcephaly can explain the small size and small brain size of the LB1 specimen. Moreover, the specimen exhibits other very obvious signs of developmental pathology. It is a bad specimen on which to base the diagnosis of a new species; its most important features are quite plausibly caused by its manifest pathology.


The argument so far against pathology has been that it cannot explain other unique morphologies, like the lack of a chin, and Tomes' root, and so forth. But this paper shows that none of these other features are necessarily unusual for modern humans, in the local and regional context. So that argument is dead, unless someone can show that there is some unique character to the combination of traits in the specimen. Since most of the features that would differentiate it from Homo erectus -- purportedly due to endemic dwarfism -- are also shared with modern humans, that seems like a problem for the species idea.


So I completely accept the argument that LB1 is pathological. A corollary is that the skeleton cannot be a convincing type specimen for a new species.
But this isn't only about LB1: there are the other small specimens. This paper makes clear that none of the features of the LB6/1 mandible are outside the range of local peoples. This is not a case of two specimens that must share some rare pathology; the paper argues that they are two specimens that share a regionally-common suite of characteristics. They aren't, in other words, unusual.

P.S. Also combined two threads on this issue, one from when the subject first came up, and one in response to the recent paper.

[ToSeek]

No Hobbits In This Shire: Researchers Say Skeletal Remains Are Pygmy Ancestors

The skeletal remains found in a cave on the island of Flores, Indonesia, reported in 2004, do not represent a new species as then claimed, but some of the ancestors of modern human pygmies who live on the island today, according to an international scientific team.

[Blob]

Title: Pygmoid Australomelanesian Homo sapiens skeletal remains from Liang Bua, Flores: Population affinities and pathological abnormalities
Authors: T. Jacob, E. Indriati, R. P. Soejono, K. Hsü , D. W. Frayer, R. B. Eckhardt, A. J. Kuperavage, A. Thorne, and M. Henneberg.

Liang Bua 1 (LB1) exhibits marked craniofacial and postcranial asymmetries and other indicators of abnormal growth and development. Anomalies aside, 140 cranial features place LB1 within modern human ranges of variation, resembling Australomelanesian populations. Mandibular and dental features of LB1 and LB6/1 either show no substantial deviation from modern Homo sapiens or share features (receding chins and rotated premolars) with Rampasasa pygmies now living near Liang Bua Cave. We propose that LB1 is drawn from an earlier pygmy H. sapiens population but individually shows signs of a developmental abnormality, including microcephaly. Additional mandibular and postcranial remains from the site share small body size but not microcephaly.

Read more (1570K PDF)

[Blob]

When scientists found 18,000-year-old bones of a small, humanlike creature on the Indonesian island of Flores in 2003, they concluded that the bones represented a new species in the human family tree that they named Homo floresiensis. Their interpretation was widely accepted by the scientific community and heralded by the popular press around the world. Because of its very short stature, H. floresiensis was soon dubbed the “Hobbit.”

Read more

[Kullat Nunu]

Their case against a new species is rather convincing...

Too bad, it was so cool, almost too amazing to be real. And now it looks like it wasn't, after all.

I think my sig is appropriate.

[ToSeek]

Taking sides in the battle of the 'hobbit'

Resolving the argument will require new material, says Chris Stringer at the Natural History Museum in London, UK. "We need a second skull to see what the variation is." Only then will we know if the hobbit was one of a kind, or a typical resident of Stone Age Flores.

[Kullat Nunu]

Let's hope they'll find another skull, preferably the hobbit variety.

[Lord Jubjub]

Ha!

The hobbit controversy now flips back to the other side.

From the BBC: http://news.bbc.co.uk/2/hi/science/nature/6311619.stm

[Kullat Nunu]

Finally there will be new excavations at the site... new specimens could settle the issue.

[publiusr]

Good stuff.

[01101001]

Revived for new news.

Flip. Flop. Flip. Flop.

Sound of a 3-foot member of the hobbit species walking to the beach with his two long and narrow feet.

Or, the sound an interested layperson makes trying to decide what to think.

BBC News: Hobbits 'are a separate species'

Since the discovery, researchers have argued vehemently as to the identity of these diminutive people.
Two papers in the journal Nature now support the idea they were an entirely new species of human.
[...]
They found that, in some ways, it is incredibly human. The big toe is aligned with the others and the joints make it possible to extend the toes as the body's full weight falls on the foot, attributes not found in great apes.
But in other respects, it is incredibly primitive. It is far longer than its modern human equivalent, and equipped with a very small big toe, long, curved lateral toes, and a weight-bearing structure that resembles that of a chimpanzee.

===

Keywords: Flores Island, Java, Indonesia, dwarf, Homo floresiensis, H. floresiensis, Hobbit, Homo sapiens, H. sapiens, Homo erectus, H. erectus

[mugaliens]

Hmmm... Orthotics?

[ravens_cry]

Well, just to remind people, the first Neanderthal specimens turned out to have pathological abnormalities that were at the time thought to be representative of the species, namely rickets. Just because it is a diseased 'hobbit' does not mean it isn't a new species.