Were Homo floresiensis just a population of myxoedematous endemic cretin Homo sapiens?

New research from the Proceedings of the Royal Society B raises the possibility that Homo floresiensis was nothing more than population of Homo sapiens that were endemic cretins. The paper, “Are the small human-like fossils found on Flores human endemic cretins?” comes from academics in Australia who

“show that the fossils display many signs of congenital hypothyroidism, including enlarged pituitary fossa, and that distinctive primitive features of LB1 such as the double rooted lower premolar and the primitive wrist morphology are consistent with the hypothesis. We find that the null hypothesis (that LB1 is not a cretin) is rejected by the pituitary fossa size of LB1, and by multivariate analyses of cranial measures. We show that critical environmental factors were potentially present on Flores, how remains of cretins but not of unaffected individuals could be preserved in caves, and that extant oral traditions may provide a record of cretinism.”

What’s cretinism, though? Cretinism is a medical condition that affects growth and development of the organism because the thyroid gland isn’t working correctly. The thyroid gland is a critical endocrine gland, one that secretes a lot of hormones, like thyroxine (T4) and triiodothyronine (T3) which do their thing in metabolic reactions and bone growth. Thyroxin and triiodothyronine are essentially made up of iodine, and deficiencies in iodine affect thyroxine and triiodothyronine production — ultimately affecting metabolism, bone development, etc. and resulting in a dwarf-like stature with small brains, but relatively,

“less severe mental retardation and motor disability than neurological endemic cretins.”

The authors of this new study suggest that what is now looked at as Homo floresiensis is nothing more than a group of Homo sapiens who lived on an island that was deficient in iodine. They look at the pituitary fossa, also known as the hypophysial fossa, a depression in the sphenoid bone which cups the pituitary gland, from the virtual endocast Dean Falk and crew made in 2005. The actual osteological feature I was taught is called the sella turcica, or the ‘turkish saddle.’ Anyways, LB1’s sella turcica is long compared to the overall size of LB1.

When compared to other populations, as well as microcephalics, Kabwe, and Mrs. Ples, LB1’s sella turcica length matched that of myxoedematous endemic cretins from China. I’m not endocrinologist, so I maybe completely wrong in this understanding, but I think the reason why endemic cretins have large pituitary glands, and thus larger sella turcicas, is because without a fully functioning thyroid gland, the pituitary has to go in overdrive — it grows larger to pump out more hormones to stimulate the weakly active thyroid. Actually, I’ve found a citation, Yamada et al.’s “Volume of sella turcica in normal subjects and in patients with primary hypothyroidism and hyperthyroidism,” where this pathology is observed and associated just as I suspected.

The authors also compared what others touted as distinctive primitive features of the Flores hominin, such as the double rooted lower premolar, to endemic cretins. But how they did it seems really fishy. They didn’t actually have the LB6 mandible, nor did they have CT scans of the premolars. What they did have was ‘captured images’ from X-ray scans of that 2005 BBC show, “The Mystery of the Human Hobbit.” Yes, you heard me right. They had screen shots from a television show, where the X-rays of the teeth flashed on the screen. Now, I know accessibility to fossils is a big problem in paleoanthropology, people just don’t wanna share… and researchers often have to resort to less accurate sources to get the data they need. But screen captures from a TV show seems flawed to me.

Why?

The authors make no mention that their screen captures came from HDTV, so I’m assuming they plucked it off of standard analog TV resolution. That’s like 704 pixels × 480 pixels resolution, the equivalent of about 0.3 megapixels! A run of the mill digital camera shoots at 7 megapixels nowadays, and the photo quality is still not that great to do a detailed morphological comparison! Regardless, from a resolution of .3 megapixels, the authors were able to compare and contrast fine details like the buccogingival ridge and measure the diameters of the crown.Screen shot of Homo floresiensis’ Premolars from a BBC TV Show

To be really honest, I don’t know how they were able to get a scale on their measurements…. surprisingly, they didn’t include their image captures. I checked the supplementary materials and don’t see any screen capture of the X-rays included. So I did some sleuthing of my own. The BBC show they got the screen captures from is online, on Google Video. I’ve linked it above. At 5 minutes and 48 seconds, the X-ray of the premolar flashes for a total of seven seconds. I’ve taken a screen capture of the closest zoom of the premolar, and uploaded it. You can get an idea of what sorta resolution we’re talking about. I’m not too convinced one can extract accurate measurements from this, especially without a scale!

The authors go on to compare a whole slew of post cranial features, such as the humeral torsion and the ‘primitive’ wrist bones — stuff we saw in September of 2007, when “The Primitive Wrist of Homo floresiensis and Its Implications for Hominin Evolution,” came out in Science. The authors conclude that the primitive wrist morphology is also a characteristic of myxoedematous endemic cretins, who in total, have brains about half the size of normal humans, way smaller bodies )the don’t grow much taller than 4 feet), and ancestral teeth and wrists. This again is all because iodine wasn’t present in their diets, so important thyroid hormones that aide in growth and development weren’t made readily.

I’d like to believe this paper, really I do. I’ve always had an inkling that Homo floresiensis was a pathological variant of humans When I look at the photos of myxoedematous endemic cretin crania, which the authors supplied in the supplemental materials, I can see similarities to Homo floresiensis. Though I wonder why the authors resorted to virtual endocasts, screen shots, and previously published measurements to do their study? It could be a case that the fossils weren’t made available to them, which then I don’t really hold the authors accountable for why they went about their study in a creative manner… but with Teuku Jacob dead, I don’t think anyone is holding the fossils from Flores hostage, or are they? Anyone care to comment on that?

One last thing, about endemic cretinism… it is seen in population far away from sources of iodine, such as the Swiss and people around the Alps. Lots of other places show it… but iodine deficiency is rarely found in island dwelling populations. That’s because the ocean and sea has a lot of iodine in it, and any food extracted from the sea… like fish, has lots of iodine in it. It is definately possible Flores hominins fished, though no zooarchaeological remains point to that, and thus had little to no iodine deficiency. Just something to think about.

    Obendorf, P.J., Oxnard, C.E., Kefford, B.J. (2008). Are the small human-like fossils found on Flores human endemic cretins?. Proceedings of the Royal Society B: Biological Sciences, -1(-1), -1–1. DOI: 10.1098/rspb.2007.1488

20 thoughts on “Were Homo floresiensis just a population of myxoedematous endemic cretin Homo sapiens?

  1. What if the Homo floresiensis began as bona fide retards, left in caves by their parents thousands of years ago; they procreated and had genetically normal children. These children, raised by retards, never received iodine during development, so they too became–essentially–retarded. Limited by their retardedness, they were never able to venture away from their small colony of iodine deprived idiots.

  2. I’m no endo either, but the pituitary produces thyroid stimulating hormone (TSH, also called thyrotrophin). And it will produce it in large amounts if there is insufficient thyroid hormone. So that makes sense as far as it goes.

    How do they explain the occurrence of only these specimens for 5000 years in one location?

    Chronic cretinism to this level would almost certainly be associated with mental retardation, and other disorders of maturation. Last (admittedly endogenous) cretin I met was wheelchair bound, and unable to walk, despite the best efforts of modern hormone replacement. I’d also be surprised if the stature was consistent between such cretins, since availability of Iodine is highly variables and human can store substantial amounts in their thyroids should they encounter some in their diet.

  3. Actually, there is good evidence that H floresiensis caught and cooked fish. This provides strong evidence against the cretinism hypothesis.

    http://www.primates.com/homo-floresiensis/index.html
    “…Other animal remains, including rats, bats and fish, show signs that they were cooked around the time H. floresiensis inhabited in the caves.”

    Some recent article discussing this claim include convincing points in rebuttal — For instance, the date range for the discoveries (90,000 years ago to 12,000 years ago,) the oldest of which clearly predates “modern human” presence in the region, and the many thousands of years of survival would preclude a merely pathological population. Keep in mind, multiple individuals with consistent morphology and size, from different time periods, were discovered. Could a cretin population survive for so many millenia, even while cooking and eating fish?

    Also, cretinism does not produce the entire suite of features, many of which are Australopithecine-like, seen in H floresiensis. There is not only the wrist bone morphology, but the gorilla-like ear bone morphology, primitive limb proportions, large feet, Australopithecine-like pelvis and shoulder morphology, distinctive brain morphology, primitive mandibular morphology (not a chin structure as is seen in modern human cretins,) and all the rest.

    I’m not convinced by the “Hobbits as modern human cretins” claim. It isn’t any more convincing than the previous “Hobbits as sick modern human” claims, and one wonders at the motives behind these half-baked claims.

  4. The authors of the cretinism paper misrepresented the data on the Flores wrist. Contrary to their claims, the trapezoid is in fact normally proportioned relative to the other carpal bones and its anatomy is essentially identical to the condition seen in nonhuman primates. Furthermore, they have misrepresented the anatomy of the pituitary fossa in their argument for cretinism. Dean Falk and Ralph Holloway, two leading experts on the evolution of the brain, rarely see eye to eye on things. Yet, they are in agreement concerning the LB1 cranium from Flores. The following excerpts are from Elizabeth Culotta’s news piece in Science (http://sciencenow.sciencemag.org/cgi/content/full/2008/305/3?rss=1)

    Those studying the original specimens and casts thereof aren’t buying the latest charge, however. “No way, Jose,” says Dean Falk of Florida State University in Tallahassee, who did computed tomography (CT) scans of the lone hobbit skull, LB1. She and others challenge the team’s conclusions point by point. For example, using CT scans instead of published photos, Falk finds that the hobbits’ pituitary fossa is no larger than usual. The fossa size “is the crux of the argument vis-à-vis cretinism, so pretty much game over,” says William Jungers of Stony Brook University in New York state.

    Ralph Holloway, a self-described “fence sitter” on the hobbit question, says he’s not leaving his fence yet. “I think [Obendorf’s team] is dead wrong on the size of the pituitary fossa,” he says, given his own inspection of a cast of the inside of the hobbit skull. “The bottom line is that almost all of the claims for pathology fail to provide evidence that matches what one sees in the Flores remains.”

  5. Great info, Caley. Thanks for sharing.

    Another point I could mention is, the 840 thousand year old stone tools, discovered on Flores Island, that are said to be very similar to the tools excavated with the “Hobbit” remains.

    This Google search brings up links pertaining to those tools:
    http://www.google.com/search?hl=en&q=flores+tools+840000

    As I noted previously, the oldest “Hobbit” skeletal remains predate the arrival of “modern humans” in the region. With this tool continuity, and the very convincing suite of morphological features seen in LB1, and apparently shared by the other specimens as well, it appears that LB1 (the “Hobbit” type specimen) was a member of a very old hominid lineage, dwelling on Flores Island for at least 840 thousand years, that vastly predates the alleged emergence of “modern humans.”

    Many other points could be made about this, but I think that’s enough for now.

    Thanks again,

    Dan Gannon

  6. A beautiful research article.

    As Dan Gannon has reminded us that they had the habit of eating fish (sea fishes, obviously, which contains plenty of Iodine); and that these gentlemen used to inhabit islands (where iodine deficiency is rarely seen compared to the hill population; possibly due to kelp, an iodine rich vegetable), the conclusion seem rather far fetched even discounting the fact about megapixels.

  7. Unfortunately, the likes of this endocrine study plus the work of the late Dr. Teuku Jacob and Dr. Berger’s Palau find continue to muck the proverbial academic waters with their own murky agendas. No wonder the creationists feel so emboldened nowadays when they observe evolutionary scientists continuously getting embroiled in a pissing contest of personal egos. As to this study, I guess the fact that there were numerous other primitive conditions of the Flores hobbit skeletons that are not readily explained by this endocrine condition doesn’t matter. We say it, so it must be so, get our five minutes of fame and basically say damn to the so-called facts!

    Of course, I have a vested interest in this discovery, having written a speculative fiction novel called Flores Girl: The Children God Forgot on the recent fossil find. If you are interested, there is more on this ongoing controversy about Homo floresiensis at http://www.floresgirl.com or catch the free Flores Girl podcast at Podiobooks.com.

    Erik John Bertel

  8. Erik,

    Thanks for the comment, but I think the back and forth-ing is a healthy part of the scientific method. It is hard to keep track of it all. Results must be accepted by the scientific community and in order to be accepted, very thorough investigations must be done and reported for people to figure out what’s going on. Sometimes the analyses are poor, like this one. Sometimes they are really high quality and accepted by many. So you really can’t say it all a pissing contest. Very few research have ulterior motives when conducting research, they’re just not as good as others in doing it!

    On the topic of ego, you sure do peddle your Flores Girl site/ebook every time new research comes out on Homo floresiensis. Don’t you think there’s some level of hypocrisy in chastising researchers for murking the waters with their own agendas when you seek similar fortune and glory?

    Kambiz

  9. Even if they were cretins due to some chemical deficiency or imbalance doesn’t the fact of their existance make anyone curious about the persistant legends throughout the British Isles about “The Little People?” Now that you know when they existed doesn’t that make it possible to go to areas where this legend is the most prevalent and do a dig there in that time horizon to see if you can find anything to prove they existed in Ireland and the other Isles? The facial reconstruction that was done on these “cretins” looks a lot like the way “The Little People have been described/depicted throughout history. Instead of infighting try and get some solid research accomplished.

  10. There’s not much fame and glory in peddling free eBooks and Podcasts at floresgirl.com, so please, I am not profiting with my opinion as do some of these researchers. I studied with a lot of these bozos that call themselves scientists and if you don’t think ego has a big part in formulating their so-called scientific opinions then I have some junk mortgages I would like to sell to you! Furthermore, the Flores finds have been vindicated by the recent research from the Stony Brook University team, researchers I was proud to study with.

    The rules are simple in academia, if I didn’t make the discovery and it doesn’t fit my rigid model of the world then I go into attack mode. I just ask people to wake up and smell the egos!

  11. mh, i don’t belief an endicrinously flawed human would survive for millenia. next, i am not convinced by any theory so far. however, the supposed erectus ancestry that is the other side of the pathology argument is also flawed. the australopitheque or even gorilla like characteristics predate that a lot, and simply imply island dwarfism and other degenerate processes, that famously retrace evolution (allways, as opposed to sufficient space and diversity). thus, i arrive at the conclusion we see a limited population of unknown and in my opinion possible sapiens ancestry. to small to stay progressive but to big to die off without concurence. interesting is it is now both proven erectus survived untill 60k< on java, and that some mixing has probably taken place. i would be more interested to the results of the gossiped interbreeding on flores, and try to do that dna comparisons. also island dwarfism is not exactly the same as endocirinous flaws or microcephalics but still produces similar (at least superficially) results.

    1. You’re an idiot Onix. No human individual can exist for millennia, however there are mutations that do sprout about from time to time. All your comments so far have been absolutely trash and I’m gonna have to ask you to stop commenting here so as to maintain the quality of the discussions here.

Comments are closed.

A WordPress.com Website.

Up ↑

%d bloggers like this: