Posts Tagged ‘hominid’

Velvet Vitality

5 July 2007

We note another volley in the Homo floresiensis ‘retort-a-thon’. Herskovitz, Kornreich and Laron (2007) argue that the Flores ‘hobbit’ may have suffered from a dwarfism-inducing hormonal defect similar to one found in humans called (!) Laron Syndrome. This disorder is marked by a deficiency of Insulin-like Growth Factor – 1.

Which, apparently, you can purchase in a bottle, with a little antler velvet extract for good measure.

John Hawks has the typically thorough breakdown of the new study.

It’s hard to imagine even the most remarkable non-hominid/n fossil receiving the kind of detailed scrutiny as the Ling Bua skeleton. Still, as in nearly all fervent fossil-debates it seems that hope of consensus will only come with the recovery and description of more material. Even then, such a resolution is, of course, hardly guaranteed.

Homo floresiensis too!

8 February 2007

Dean Falk and table full of hominin brains. (Photo: Michelle Edmunds)

We’re still stalling on phugoid fliers, not to mention most beautiful bird #5. In the meantime you might care to read up on the latest chapter of tit-for-tat over the putative miniature hominin Homo floresiensis.

As we saw in a previous post, the discovery of H. floresiensis (quickly dubbed as a “hobbit” by the popular press) in the Ling Bua cave on the Indonesian island of Flores quickly sparked a heated debate. One camp maintained that the remains belonged to a previously undiscovered species of Homo that showed signs of insular dwarfism, a phenomenon seen in a great range of living and fossil island taxa including mammoths, dinosaurs, goats and rails. The opposition retorted that ‘H. floresiensis‘ weren’t a new species at all but plain old ordinary H. sapiens striken with some type of pathology such as microcephaly.

Four years after the discovery, the debate continues to rage. The latest installment is a paper by neuroanthropologist Dean Falk and colleagues appearing in, where else?, PNAS. Falk et al. examined computerized 3-D endocasts of the Ling Bua remains as well as known human microcephalics. Their conclusion: H. floresiensis is a new species and not a microcephalic.

As compelling as the new study may be, it’s quite unlikely to be the end of the debate. Nothing short of some fresh corroborative material, perhaps including some juvenile remains is likely to quell the skeptics. Fortunately, Ling Bua is being re-opened. Rumors of a ‘lower chamber’ at Ling Bua open the door to the emergence of much more interesting details from one of the greatest (for humans at least) scientific puzzles of the decade.

Further reading:

above links will take you to the abstract and the opportunity to request a reprint.

John Hawks’ anthropology weblog has extensive coverage of the H. floresiensis ‘wars’ and a thorough treatment of Falk’s new paper.

Carl Zimmer also has post on the new paper.

I’m not entirely sure why the background has gone fuzzy. Perhaps it has something to do with the dropped shadow.

Where Has All the Carrion Gone?

20 December 2006

It’s rather easy to overlook the dead, they don’t move much and they hardly have anything to say. Nevertheless, it’s an apparent truism that there are not enough bird carcasses lying around, compared to the shitstorms of flocking pigeons, starlings, spugs and whatever other avian excretory plagues defile our coveted personal transport systems. AÖrstan recently parsed this question over at Snail’s Tales.

One explanation for the dearth of dead bird carcasses rests upon the ability of necrophages to quickly process latent biomass into food. There is undoubtedly much truth to this, and I loath to think of wading through a world without scavangers and decomposers.

The Snail’s Tales post led me to A Snail’s Eye View of dipteran remediation complete with some beautiful fly graphics of calliphorids that “appear from nowhere” (spontaneous generation!) and the aptly named sarcophagids like those fornicating on the shovel handle above.

I argue that this is only part of the story.

Anyone who hikes with dogs is aware that there is no shortage of carrion in various states of rereification out there:


Though we were able to keep Clyde from downing the above wriggling protein-fest, he soon arrived with another partially decomposed rodent proudly clenched in his jaws. He also rustled up some quasi-disarticulated Mule Deer limbs on the same hike. I probably ought to chalk up my queasy GI sentiments about eating carrion not to any moral superiority on my part, but to Clyde’s superior constitution1.

Early on, it would seem that Homo was an opportunist par excellence, surely not shying away from a free meal. Yet somewhere along the way tools or culture or behavior weakened our stomach and we lost the taste for a nicely ripened marmot carcass with good maggot marbelling.

How exactly our digestive weakness, or disgust, got cross-mapped across onto our regard for various “non-normative” sexual behaviors will be the territory for future enlightened generations of neuro-historians2, and perhaps also the subject of a few well earned chuckles, though I’m betting it had something to do with death and maybe Catholics.

Anyway, anyone with open eyes is likely to observe a number of dead birds across their daily transects whether in city or country3. On a recent trip down I-5 I counted no fewer than six dead owls, mostly Tyto alba probably. Carel accounts 27 dead Longears along a Nevada highway and I wonder how many I missed. There are many dead raptors to be seen along our “rights-of-way” drawn in no doubt by the car-killed carrion buffet and perhaps by the unintentional baiting of rodents et al. by cast off tasty morsels.

Birds fly, make noise, aggregate in large numbers…they’re remarkably conspicuous animals. It’s notable that there are a lot more birders out there than mousers or lizarders or spiderers. But when they die they’re a bit more crytpic.

I imagine that the main source for the discrepancy is our general disregard for the dead animals we step over and around everyday without a second thought. A flattened Rock Dove is much easier to overlook than one flapping about. We generally don’t go hunting for the thousands of half-rotten starlings littering our alleys and gutters and chimneys so we should be wary of assuming their absence.

1– Of course, Clyde is no stranger to pleasures of the hunt. Moments after I took the top photo, and seconds after frolicking joyfully in the surf,

Clyde stalked and killed the first of two vertebrates he’s dispatched in the eight months since we’ve had him. The victim was a shorebird probably much akin to the mummmy found in the sand. I don’t think it was a Snowy Plover. Still, I feel terrible about it.

2 – Note the optimism.

3 – Please, I spelled it properly, check again.

It is autumn and my camouflage is dying

12 September 2006

Last night’s Silver Jews show made me feel 19 again. Except that I could freely order $6 beers at the bar. Dave was wearing a Fall t-shirt and name-checked Bomb. Punks in the beerlight indeed.

Still, I’m a little sorry I missed this show.

Homo floresiensisn’t?

23 August 2006

Carl Sagan (paraphrasing LaPlace) famously observed that in science, “extraordinary claims require extraordinary evidence.” The 2004 announcement of a new species of “dwarf” hominid, based on subfossil material from the Indonesian island of Flores was in all respects extraordinary. Dubbed Homo floresiensis, our new cousins were quickly and cutely rebranded as “hobbits” by the popular press.

 


Two page spread from the April 2005 issue National Geographic (German language version).

The evidence, for its part was similarly extraordinary, a remarkably complete set of remains including a softball sized skull which appeared to be more closely akin to H. erectus than to H. sapiens. Associated with the skeleton were numerous lithics, the remains of tools used to hunt and process food. This material, along with additional skeletal remains were taken as the legacy of an extinct race of miniature humans with a unique evolutionary history.

 


Varying degrees of smugness in H. erectus (left) “H. floresiensis” (center) and H. sapiens (right and rear). (AP)

Of course one investigator’s exceptional proof is another’s dubious outlier. Much like the similarly extraordinary reports of extant Ivory-Billed Woodpeckers in the woods of Arkansas, the description of H. floresiensis garnered immediate rebuttal. The new skeleton was not a new species, said the critics, but a pathologic H. sapiens fossil, one with some type of microencephaly.


Reconstruction of H. floresiensis by Peter Schouten (left) and photograph of a microcephalic H. sapiens (right). This figure is an out of place artifact.

Partisan camps formed quickly and a publishing war began with both groups repeatedly declaring victory but failing to close the debate. The latest definitive report comes from an international team of Indonesian, Chinese, American and Australian scientists. Writing in this weeks PNAS, the authors conclude from a 140 point analysis of the skull that it is the remains of a diseased human (H. sapiens) with an abnormally small skull from a naturally small-statured (i.e pygmy) population.

 


The extreme asymmetry of the Flores skull is taken by Jacob et al. (2006) as an indication of pathology.

While I’m sadly under-qualified to have a relevant opinion on the validity of the taxon, I am reasonably certain that the debate is far from closed.

Of course, extraordinary debate is nothing new to paleoanthropology. The original H. erectus fossils, found by Eugène Dubois on the Indonesian island of Java in 1891, remained bones of contention until Dubois’ death in 1940. Dubois’ accession of the remains into a box hidden underneath his dining room floor and stubborn refusal to allow other scientists to examine the fossils didn’t help matters.

Last year’s report that the Indonesian government is denying access to the cave where the H. floresiensis remains were found is troubling. Even extraordinary evidence is useless when it’s kept out of reach of the global scientific community.

Extensive discussion of the H. floresiensis controversy, as well as a detailed analysis of the most recent rebuttal can be found at John Hawks’ weblog.

Above and below: New species or diseased pygmy?