The Hobbit on Darwin Day

| 23 Comments

A few months ago I attended a talk by Professor Colin Groves of the Australian National University: ‘An update on Homo floresiensis, a.k.a. the “Hobbit”’ (available on YouTube in seven installments: 1, 2, 3, 4, 5, 6, 7). As is well known, there has been an unusually bitter scientific debate over the last couple of years as to whether the hobbit is indeed a new species, or just a small microcephalic human. The term ‘microcephaly’ covers a range of conditions which cause unusually small brain sizes. (Disclaimer: Groves is not a disinterested participant in this debate, having coauthored a paper which argues against the microcephalic interpretation.) Groves went over a long list of unusual features of the hobbit. The limb bone ratios are unlike those of any apes or humans. They are also very robust: in spite of their small size, hobbits would have been remarkably strong. The arms are too long for humans, and they had unusually large feet (like Tolkien’s hobbits!). The lower jaw lacks a chin, a feature found in all humans (even people who look chinless), and that is also true of a second jaw which has been found. The upper end of the humerus has a twist not found in modern humans, but which was then found in the Turkana Boy Homo erectus/ergaster skeleton once it was looked for. Groves’ conclusion: all of these features make it overwhelmingly unlikely that the hobbit was just a small microcephalic human.

In the question time afterwards, I asked Groves whether the scientific community was coming to any consensus about the hobbit.

The reply was unequivocal: although the debate is very heated, the microcephalic interpretation is supported only by a small number of scientists, and rejected by an overwhelming majority. At a recent conference, Colin was able to talk to a number of prominent paleoanthropologists. All were under no doubt that the hobbit is a new species. And, during one of the talks, when a reference was made to the microcephalic interpretation, a ripple of amusement went through the audience. Creationist Marvin Lubenow, in a new article “Hobbits” were true humans! claims that

In contrast to the discoverers’ claim that these fossils represent a new human species, a second theory gaining popularity is that these fossils do not represent a new human species but instead were dwarfs or pigmies possibly suffering from microcephaly, having abnormally small bodies and brains.

but this would appear to be wishful thinking. The microcephaly supporters may be making a lot of noise, but not many converts.

By the way, Mike Morwood, one of the discoverers of the hobbit, was present at the talk and I met him very briefly. He had just coauthored a new book, The Discovery of the Hobbit, available in Australia. It has now been published in hardcover in the USA in May 2007 under the title A New Human. A must-read for anyone wanting to know more about one of the hottest paleoanthropological discoveries ever.

23 Comments

I always thought the microencephalopathy claim was improbable.

1. Hominids who die and fossilize are very rare. As a top predator, in prehistoric times hominids have never seemed to be all that numerous.

2. Microencephalics are very rare. Having a head and brain quite small and not real functional just isn’t going to be common.

So with two rare occurences, the probabilities would be multiplicative and a fossilized genetic defective would be even rarer. Chances are with rare fossils, the typical would be most probably represented.

In addition, microencephalics would be at a severe disadvantage in prehistoric times where hunting and gathering and avoiding predators and accidents would be routine activities. I have a hard time believing many would reach adulthood.

It would be nice to get some DNA data, maybe mt. DNA from a tooth or something. These bones don’t seem to be very old.

The creo claims are their usual lies. Fossil hominids have always been a big problem for them as there is a reasonably complete set going back from modern humans to something like a common ancestor of chimps and humans. Although to be sure, the farther back one goes in time the sparser the remains.

So everything is just funny looking humans.

Or funny looking apes.

Maintaining a delusional belief system is hard work. They are rowing against the current of knowledge. Every new discovery in many fields, which occurs frequently, is something to be explained away with a new pack of lies. A bit of poor theology, basing a cultish version of a religion on continuous lies.

Thanks.

By the way, you can catch a back view of me asking the question at the very end of the 7th video segment. Groves starts his answer, but then the video ends just as he’s getting into it.

Raven: the bones aren’t particularly old, but they were in a hot, humid environment - exactly what you don’t want if you hope to extract DNA.

I’m not sure why creationists even care. How does arguing that it was a microcephalic Homo sapiens help creationists? The dating is still over 6000 years, and they believe in giants and the like (without fossil evidence). The hypocritical “religion neutral ID” that nobody except maybe one musician even believes in ostensibly doesn’t deal with this issue (therefore when Dembski and the like argue ignorantly in favor of microcephaly, the prove their hypocrisy.)

Applying probability arguments here is a bit tricky (unless microcephaly can be conclusively eliminated by continued pathologic examination, in which case, barring a third possible interpretation, the probability becomes “one” that it’s a newly discovered species).

It’s certainly true that before the fossil was discovered, the probability that a microcephalic early humanoid fossil “would be” discovered within any given time frame was very, very low.

But of course, we might also have thought that the probability of new (to us) and extremely distinctive early hominid species being discovered within a certain time frame was also low.

Now that the fossil has been discovered, though, it’s a question of the probabilities, conditional on the fact that this unexpected fossil has been discovered. Again, barring a third interpretation.

Technically, it’s P(A happened)/(P(A happend) OR P(B happened)), or in arithmetic, P(hobbit) divided by (P(hobbit) + P(microcephalic)). We can never really calculate this, but note that if P(hobbit) is very “low”, but is much greater than P(microcephalic), the conditional probability that it’s a new species is very high, possibly approaching one.

By the way, I HATE the fact that people (including me) keep calling this species a “hobbit”, but I guess that’s about as likely to change now as “junk” DNA.

and that is also true of a second jaw which has been found.

Further undermining the microcephalic theory would be finding remains of additional hobbits. That appears to have already happened.

The probability of one microcephalic making it to adulthood and getting preserved is low. With additional specimens, you have to start postulating a whole population of genetic accidents.

One has to remember, this is the stone age we are talking about here. All they have is their wits and a few rocks and wood and they have to survive for decades. Being retarded and surviving isn’t going to be easy.

The dating is still over 6000 years,

What dating? To some creos, radioisotope dating doesn’t exist or work or something.

So the fossils cannot be older than 5,768 years and are probably much younger. With a little handwaving, it is easy to condense 4.5 billion years of history into a few thousand. LOL

DNA extraction has already been attempted. Even though the bones aren’t that old, the location (from what I understand) where they were found is wet and hot…not the best place for dna preservation. I’ve only done a bit of ancient dna extraction myself, and I’ve been able to get dna out of samples which I’d thought initially that I couldn’t, but those were from dry, colder areas. From most of what I’ve read it just doesn’t seem likely. Plus, I would think that the possiblity of contamination is higher. Still, though, it should be tried on all the samples obtained. And I read somewhere recently that they are trying to get more samples from a lower chamber in the cave.

If they discovered these in the middle of Europe, surrounded by other Erectine fossils, I might be more inclined to believe the microencephaly claim. (Another hurdle would be the unique characteristics not common with microencephaly.) But these were out on the island of flores, separate from everything else, with more bizarre species - and the environment itself suggests a species or sub-species of human that is distinct. And that’s what they seemed to find.

So even in a non-socially-touchy scientific subject, there’s a consensus that has built, and the media isn’t recognizing that consensus and is keeping the “controversy” alive. This is very instructive.

and they had unusually large feet (like Tolkien’s hobbits!)

Ah, but were they exceptionally furry as well?

Inoculated Mind -

So even in a non-socially-touchy scientific subject, there’s a consensus that has built, and the media isn’t recognizing that consensus and is keeping the “controversy” alive. This is very instructive.

I certainly have different view of the mainstream media than this. It is a “socially-touchy” subject.

Rather than make a broader comment, I’ll confine myself to pointing out that creationism and ID are tightly linked to a social and political agenda of replacing current law with cherry-picked harsh “Biblican Law”, and usually of enforcing a harsh laissez-faire economic system, too, although the latter is rather hard to link to any part of the Bible. As always, I welcome any liberal Biblical creationist to jump up and provide even one counter-example.

Although the exact opinions of creationist fundamentalists are held by a relatively small segment of the population, creationists are perceived to be a relatively loyal part of a larger “conservative” coalition. Atheist or agnostic conservatives like Karl Rove seem to be quite willing to advance the creationist agenda.

It is the overwhelming opinion of every scientifically educated or interested person I know that the media as a whole favors creationism, relative to its actual merits. Not only are fake “controversies” constantly being kept alive, but the few media outlets that report on creationism in a negative way tend to be low circulation print vehicles aimed at narrow and highly educated audiences, such as Reason or the New Yorker. When an editorial on evolution is published in a more broadly aimed local media outlet, it is, in my observation, 90% likely to be a cut and paste repition of long-disproven creationist talking points.

I’ll restrict myself to these few, easily defended points, as I am rather busy today.

Jim,

Has much been with the tools found at the LB site since their original description? The fact that such a small-brained species had a technology all their own is, to my demented mind, way cool. Did Colin Groves say anything about the tools?

MB

harold: In re: your statement:

“It is the overwhelming opinion of every scientifically educated or interested person I know that the media as a whole favors creationism, relative to its actual merits. Not only are fake “controversies” constantly being kept alive,”

Let’s all be clear on something. The media favors WHATEVER sells. Media corporations are in the business of providing prospective purchasers to advertisers - PERIOD. Individual reporters might work hard to report the news, but the clients of the media corporations, including editorial staff, are not the subscribers/readers.

ANY topic which can be perpetuated into an onging controversy sells to repeat readers, who are the ideal candidates for the repetetive reinforcement nature of advertising. What media outlet is going to kill all future sales (that’s to advertisers, not readers) by chasing away its own clients’ prospects with a dead end story when a serial topic can be fostered? Controversy sells, and sells, and sells.… conclusions sell ONCE.

Keep this in mind when trying to fathom the coverage of this topic and you will be a little less frustrated. Not that it will no longer be frustrating, but if you treat it as a business consideration, it is a little easier to at least understand.

Jim,

Did Colin Groves mention the tools found at the site. After watching the UTube lecture, I did not hear anything about the tools. Has anything else been done with the tools since their original description? It seems to me that a small-brained species that had their own technology is way cool.

Odd how “unpopular” is always described as “gaining popularity”.

Nice to get an unequivocal statement on the consensus, since the media isn’t reporting.

raven Wrote:

I always thought the microencephalopathy claim was improbable.

It was somewhat more believable at the time it was suggested that the skull specimen was diseased, based on asymmetries. Though the strength of that claim was hard to assess for a layman such as me when the skull reportedly was found in the condition of ‘wet paper’ consistency. And indeed, it seems to have evaporated.

This year at the annual meetings of the American Association of Physical Anthropologists, there were a couple of talks on the “hobbit”, along with plenty of chat in the halls and at the bar. A general consensus is emerging that the microcephalic hypothesis is not well-supported. Some are adamant, but most, like myself (who cares more about monkeys anyway), are guardedly putting money on the separate species hypothesis.

The idea that microcephalics are too improbable to be preserved is largely irrelevant. Specific claims have been made concerning the morphology of the fossils, leading to testable hypotheses. If it is a microcephalic, then indeed one was preserved regardless of the probabilities.

So far, most evidence leans towards the hypothesis that this is indeed a new taxon. My favorite bit came from a talk by Matt Tocheri (Am. J. Phys. Anthropol. Supp 44: 232-233), who compared wrist bones of humans and other primates. Apart from providing a meticulous functional model explaining variation in the form of the trapezoid (a bone at the base of the thumb and index finger), he tossed in an image of the “hobbit” with modern humans and apes. It looks like an ape (as do earlier hominins – and pre-emptively, no this does not mean that they could not make tools, just that the wrist bone was not yet specialized like modern humans). As far as Matt could tell, microcephalic wrist bones do not show this pattern. However, microcephaly is a symptom with many possible causes, and there is considerable variation in the morphological abnormalities associated with it. Still, though it might seem trivial, it was devastating to the microcephaly argument, because it is a clear, consistent feature of modern humans across the board.

Larson et al. (Am. J. Phys. Anthropol. Supp 44: 151 –presentation given by Bill Jungers) presented a talk that aggressively and directly countered claims about the postcranial anatomy of the hobbit being abnormal. This may have been the “ripple of amusement talk.” If so, what actually happened was that Eckhardt – a primary proponent of the microcephaly argument – stood up after Bill’s presentation and critiqued it, to which Bill replied “man, what color is the sky on the planet you live on.” Debates get heated in this business.

Regardless, the issue is not firmly settled yet. The case for microcephaly seems weak at this point, but those of us interested in the fossils, but not actually studying them personally, need to let the work get done and have patience.

Tom G. -

I agree 100%.

But they also want to sell some things a little more than they want to sell other things.

There’s a phenomenon a friend of mine has termed “anything for a flat tax”. People and institutions who are on the “conservative” side of economic issues will sometimes tolerate or even promote “conservative” authoritarian and discriminatory social issue positions with which they (claim to) privately disagree, or even which would be devastatingly harmful to them personally, in order to advance their economic agenda.

Some few conservative commentators have criticized ID, and we see the odd character like Ron Paul, but in my experience, a great many “economic conservatives” don’t have a problem with loss of rights and denial of science, as long as it is associated with helping “their guys”.

I suspect that this tendency is a partial factor as well. Studies show that mainstream journalists are “liberal” on social issues, but considerably more “conservative” than the general population on economic and foreign policy issues. And it seems that when perceived economic self-interest butts up against freedom, freedom is often viewed as expendable.

Note - although I am “liberal” or “progressive” by American standards, this post is intended to be descriptive not proscriptive.

There’s a phenomenon a friend of mine has termed “anything for a flat tax”. People and institutions who are on the “conservative” side of economic issues will sometimes tolerate or even promote “conservative” authoritarian and discriminatory social issue positions with which they (claim to) privately disagree, or even which would be devastatingly harmful to them personally, in order to advance their economic agenda.

This is one of the most succinct decriptions of American libertarianism I’ve seen in a LONG time.

There is no doubt that all sides of the debate over “H. floresiensis” have made mistakes, and taken calculated risks in their claims. The case for microcephaly is weak, but not dead. The case for evolutionary dwarfism is weak, but not dead. The Flores fossils are indeed very perplexing, and one way or another will add a very interesting sidebar to the constantly developing scientific picture of human evolution.

But we must not jump to quick conclusions. When the news of the Flores fossils first broke, I was e-mailing a colleague at U. Michigan about a separate matter, but regarding the Flores material, asked: “what are the chances of digging up a skeleton of an achondroplastic dwarf, as opposed to a normal member of a species?”

I sent that note off, and then looked up on my book shelf, where I had the famed “Adena Pipe” of an achondroplastic dwarf (not to mention a poster of the same figure over my right shoulder.) The point was, to me, that it is not so rare to find evidence of dwarfism, and there are many kinds of dwarfism, and not microcephaly, that might account for the peculiar configuration of the Flores skull.

The Flores fossils will be deciphered before too long … then we can get back to the Neandertals, so close to us, but so distant. Perplexing problems of unique ancestry will persist as long as we have such a rich fossil record. But much to the creationist/IDist distress, the basic patterns of human evolution are set, quite literally, in stone, and only willful ignorance can deny that. Only the details remain in question.

One thing that is not advantageous is the scurrying of non theists, as they may be frequently seen to do, to meet some spurious claim put forth by the believers that seems to carry some scientific cache. In some instances they just might have a cute angle, but it will not have been well and thoroughly thought out. This much is evident and has been shown here by PZ and y’all..

One thing that science has in its favor is the ability do defer judgment. To claim that there is not enough detailed knowledge to support a declaration of certainty. And to be optimistic and of good cheer while doing so. The believers get stuck on this every time. They think we either actively apply our will to negate the existence of their preferred spook or that we are so fundamentally and woefully lost in sin that we cannot see; our eyes having been somehow blinded by lesser spooks. They simply are at a loss when they see godless heathens doing as well as they themselves, judged according to their own magic code. What they don’t know is that basic human behavior already encompassed the Golden Rule (core of most magic codes) long before it was ever written down; else how to arrive at the point of actually writing it down?

At least for this functional human, there is nothing of paradigm-shifting import between the core of religious teaching (I am errant in some details while speaking broadly with a grin) and what I learned from my own experience and from the guidance and discipline of my secular parents. By the time religion was explained to me thoroughly enough for me to catch its drift I was able to react with a fairly confident shrug and thought, ‘“I know that.”

What might be productive is to temper the temptation to parry all the thrusts of the IDers and other godwallopers (my spell checker finds that word as funny as I do!) and let human curiosity and inventiveness, most noticeably and effectively exemplified by Science! and Free Enterprise! do what they usually do; win out in the end and carry the day.

We are in this for the long haul. Though the flush of pride and victory that follows a successful skirmish can make the people dance and feast for a night, only the far outcome of today’s arguments will be what our children will see. Best to take the time to be deliberate and forthcoming with an eye to “interesting times” to come, which we will neither suffer nor enjoy. Those who come after us will need some guidance in the art of arguing not only persuasively and with evidence freely offered from the stock at hand, but also with the ability to disarm, harmlessly, the believer. This shouldn’t be too hard on the believer since he has most likely had some advice concerning similar tactics, that is, witnessing or proselytizing or whatchamacallit.

What I mean is that rationality best serves itself when it does not emulate the shrillness or the certainty of the believer. They will call it smugness when we shrug and say, “I don’t know.” They’ll cast slings and apocrypha at us like dung at a wall. What did we expect? What they need desperately is to be shown that exemplary and productive and honored lives have been, are being and will be led by folks who just don’t have no juju, no savior, no go-to spook. And this repetitively, I fear.

As a former believer I can assure you that some skythumpers are fully and amply convinced by the stories they’ve been told.

Aren’t we possessed by a similar assurance? Not faith, but what may be well described as reasonable suspicion? Lay it out there and let it ride. You got the time. Some believers have had thousands of years to improve life on earth. In the last two hundred fifty or so Science! and Free Enterprise! has left them in the dust and there is no reason to suspect that this will change. We have the momentum and the evidence that relieves us of the need to call our opponents unflattering names. Kid stuff.

Growing up is hard and I’ve damn near had my share. Thing is, if I don’t die I still gotta grow. Up. oh man.

Crudely Wrott -

I can’t really understand your post, but if one of your concerns is that all of the pro-science posters here, or all of the scientists engaged in legitimate debate and investigation of the fossil in question are “non theists”, I can assure you that this is certainly not the case.

Likewise, no-one here has made a dogmatic declaration of what the correct interpretation of the fossil should be. There seems to be a growing consensus, among both people who know a great deal about the fossil, and people who know about microcephaly, that that particular interpretation has been weakened.

Even if the fossil were microcephalic (in the medical sense), YEC would be disproven by the dating, but no more so than by the dating of anything else that is greater than 6000 years old. The claims of “intelligent design” are false, but not directly related to this particular fossil. There is no support for any kind of creationism here.

Crudely Wrott -

Actually, I now realize that you are writing from a secular position, and that your post is not terribly difficult to understand. My apologies for not reading more carefully.

At any rate my post above is still accurate.

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This page contains a single entry by Jim Foley published on June 20, 2007 7:24 PM.

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