The Dmanisi skulls and creationism — The Panda's Thumb (Legacy Archive)

I recently got a copy of the new 2nd edition of Marvin Lubenow's book Bones of Contention, a creationist book about the evidence for human evolution. I'll do a fuller review of it later, but there's one thing I want to comment on now. In 2002, the discovery of a new hominid skull from Dmanisi, Georgia, was announced. This skull had a very small brain size of 600 cc, in the Homo habilis range. Two other skulls which had been announced in 2000 had brain sizes of 650 cc and 780 cc. The skulls had a mixture of features from H. erectus and H. habilis and although the smallest one seemed slightly more primitive, the discoverers saw no reason not to put them all in the same species.

I found these skulls particularly interesting because they nicely straddle the gap that creationists like to claim separates humans from non-human primates. Generally the less-incompetent creationists (i.e. those who don't still think that Java Man and Peking Man are ape or monkey skulls) have a dividing line of about 700 cc; usually anything above that is human, and anything below it isn't. Although there are a couple of fragmentary habilis skulls estimated to be in the 650-700 cc range, there weren't any moderately complete hominid skulls between about 620 and 720 cc, so that became the "gap" separating humans from non-humans. But now we have three skulls from the same place, the same time, and of the same species, sitting smack on top of that gap - above, below, and in it. How, I wondered, would Lubenow handle it?

74 Comments

Steve Reuland · 18 May 2005

So Jim, does that nifty graphic of skull volume vs. time have the Dmanisi skulls in it? There do not appear to be any obvious gaps in that graphic to begin with.

Dave S. · 18 May 2005

Steve -

These skulls (age ca. 1.8Ma) fit right into that graphic, although that figure by McHenry was made in 1994, before the Dmanisi find.

I think Jim is more referring to the dividing line between where creationists generally think the creature was human (>700 cc) and where they think it was an ape (<700 cc). The further away from that demarcation, the more consistent they are. (see here).

Here we have what appear to be fossils of the same species sitting on either side that line. Where will their opinions fall (man or ape), and more interestingly, why?

So far, they've chosen the time-honoured method of avoiding the question or offering a vague response.

Bayesian Bouffant, FCD · 18 May 2005

Bullying teenager to Dmanisi Timmy: "Your mama was an ape!"

EmmaPeel · 18 May 2005

Jim, you might mention this at the book's Amazon.com page.

Bayesian Bouffant, FCD · 18 May 2005

Jim, you might mention this at the book's Amazon.com page.

Heh. Take a look at this:

Customers who bought this book also bought * DARWINS BLACK BOX: THE BIOCHEMICAL CHALLENGE TO EVOLUTION by Michael J. Behe * Uncommon Dissent: Intellectuals Who Find Darwinism Unconvincing by John. Wilson * Icons of Evolution: Science or Myth? Why Much of What We Teach About Evolution is Wrong by Jonathan Wells * Evolution : A Theory In Crisis by Michael Denton * The Biblical Basis for Modern Science by Henry M. Morris * Not by Chance: Shattering the Modern Theory of Evolution by Lee M. Spetner

Apparently he's preaching to the choir. And a snippet from another customer review:

Read some real scholarship by Dembski, Behe and Ross.

You betcha. As soon as any one of them produces some real scholarship.

TAS · 18 May 2005

is creation wrong?

Cubist · 18 May 2005

is creation wrong?
—

What do you mean by "creation"? The reason I ask, is that there's a few different ideas people refer to when they use the word "creation", and the answer to your question depends on which idea you're asking about. If, by "creation", you mean "Young-Earth Creationism": Yes, "creation" is wrong. Young-Earth Creationism is contradicted by the relevant physical evidence (so it's bad science), and it can only be salvaged by presuming that God did it all one way while simultaneously jiggering the evidence to make it appear that He did it all some other way entirely -- i.e., by presuming that God is a deceiver of literally astronomical proportions (so it's bad theology, too). If, by "creation", you mean "God created everything": This isn't a proposition science can test. It may be right, and it may be wrong; either way, it's a matter of faith, not a matter of science. If, by "creation", you mean something else: Tell me what you mean, and I'll take my best shot at telling you whether "cration": is right or wrong.

Flint · 18 May 2005

TAS:

No, creation exists. How it came to exist, now, that's a good question. I doubt anyone knows.

Aureola Nominee · 18 May 2005

...except that the very word, 'Creation', is begging the question.

Michael Finley · 18 May 2005

. . . except that the very word, 'Creation', is begging the question.
— AN

What question might that be?

Globigerinoides · 18 May 2005

More to the point, TAS, is: Did your Creator fake the Dmanisi fossils as a test of our faith in TV preachers and conservative politicians who use religion as a means to power?

Michael Finley · 18 May 2005

What, exactly, establishes that the skulls found in Dmanisi (or any other 'transitional' fossil) are from a species ancestral to homo sapiens? Is it the conjunction of the facts that (1) the skulls of the former are similar to those of the latter, and (2) the former were found in older dirt than the latter? Or are there additional considerations?

Duane · 18 May 2005

Gee, I thought "Bones of Contention" was a popular book by Roger Lewin about the history of paleoanthropology. Did Lubenow steal the title and just replace "Controversies in the Search for Human Origins" with "A Creationist Assessment Of Human Fossils?" I should look up a copy of Lubenow's book, but, in the meantime, does any know if he even references Lewin's book?

John · 18 May 2005

Dave S.

That skull graphic is incredible! Any chance that those data exist in tabular form anywhere, to anyone's knowledge? I'd like to replot it, sprucing up the color and symbols on it a bit, to use as a teaching tool. If anyone knows the original citation, perhaps that would help. Thanks in advance.

Brian Andrews · 18 May 2005

If, by "creation", you mean "God created everything": This isn't a proposition science can test. It may be right, and it may be wrong; either way, it's a matter of faith, not a matter of science.

It's equally likely that a little teapot created everything.

No, creation exists. How it came to exist, now, that's a good question. I doubt anyone knows.

if you men that the world around us exists I believe it. If you mean that some intelligent agent created it that isn't at all self evident. Science may some day prove this happened but until then there's no reason to think so.

JRQ · 18 May 2005

If anyone knows the original citation, perhaps that would help.

I've seen that partifular figure around a lot. Lee and Wolpoff, 2003, paleobiology have a table and similar figure for the Homo genus going back to about 1.8 ma that includes the dmanisi skulls. Lee has a link to the PDF here: http://faculty.ucr.edu/~shlee/publications.htm

Michael Finley · 18 May 2005

Science may some day prove this happened but until then there's no reason to think so.

'Scientific truth' is co-extensive with 'truth'; therefore, if science can't establish something, it can't be established. Except that this last statement is supposed to be true, and science can't establish it. Thus, the claim is self-defeating (i.e., self-referential incoherent).

jeffw · 18 May 2005

Except that this last statement is supposed to be true, and science can't establish it. Thus, the claim is self-defeating (i.e., self-referential incoherent).

By that definition, "God" is also self-referential and incoherent. "I am that I am." Science is easier to believe and much easier to observe, so we'll stick with it.

Jim Foley · 18 May 2005

The brainsize vs. time graphic came from a 1994 paper by Henry McHenry referenced here:

http://www.talkorigins.org/faqs/homs/a_brains.html

There never really was a gap; creationists just tended to gloss over fossils such as OH 12 which were too near it, or make an arbitrary decision as to whether an individual fossil was a human or an ape. What's significant about the Dmanisi skulls is that for the first time, we have skulls from a single population that straddle the gap. That leaves creationists with a tough dilemma: either some of them are remarkably large and humanlike apes (if they're all apes), or some are remarkably small and apelike humans (if they're all humans), or they're a mixture of apes and humans. Any of those choices is an unpalatable one for creationists.

Randall Wald · 18 May 2005

Except that this last statement is supposed to be true, and science can't establish it. Thus, the claim is self-defeating (i.e., self-referential incoherent).

Hey, if you want to go with solipsism, that's fine too. Just don't expect to make many important discoveries.

Michael Finley · 18 May 2005

Jeff,

What can I say except that you need to read more philosophy, say PHIL 101 at your local community college.

"I am that I am" is a tautology, not a self-contradiction. These are opposites.

Michael Finley · 18 May 2005

Hey, if you want to go with solipsism, that's fine too. Just don't expect to make many important discoveries.

Really folks, please read Sophie's World or something.

JRQ · 18 May 2005

'Scientific truth' is co-extensive with 'truth'; therefore, if science can't establish something, it can't be established. Except that this last statement is supposed to be true, and science can't establish it. Thus, the claim is self-defeating (i.e., self-referential incoherent).

Isn't it extraordinary, then, that assuming the truth of an unestablishable proposition should seem so universally beneficial; that it so readily results in an illusion of objective progress...especially considering the same illusion does not result from assuming the truth of so many other propositions...

jeffw · 18 May 2005

By that definition, "God" is also self-referential and incoherent. "I am that I am." What can I say except that you need to read more philosophy, say PHIL 101 at your local community college. "I am that I am" is a tautology, not a self-contradiction. These are opposites.

And you need to learn something even more basic - *how to read*. I said self-referential, not self-contradiction. Idiot.

JRQ · 18 May 2005

What, exactly, establishes that the skulls found in Dmanisi (or any other 'transitional' fossil) are from a species ancestral to homo sapiens? Is it the conjunction of the facts that (1) the skulls of the former are similar to those of the latter, and (2) the former were found in older dirt than the latter? Or are there additional considerations?

I don't think anyone knows these skulls or even this population was necessarily ancestral. Rather, I believe what you need to consider is that presence skulls with these characteristics at these times in these places are very difficult to explain without the presence of AN ancestral line somewhere nearby with increasing brainsize over time. Its also worth pointing out that with the exception of the Feldhofer neandertal skull (I think), none of these were known when Origin was published.

Sir_Toejam · 18 May 2005

"What can I say except that you need to read more philosophy, say PHIL 101 at your local community college."

and you have exhibited an even lesser understanding of biology than this, finley, yet you never seem to take your own advice.

snaxalotl · 18 May 2005

Isn't it extraordinary, then, that assuming the truth of an unestablishable proposition should seem so universally beneficial

for example: "Some of [the Jews] had their skins flayed off them and their flesh was flung to the dogs. The hands and feet of others were cut off and they were flung onto the roadway where carts ran over them and they were trodden underfoot by horse....And many were buried alive. Children were slaughtered in their mothers' bosoms and many children were torn apart like fish. They ripped up the bellies of pregnant women, took out the unborn children, and flung them in their faces. They tore open the bellies of some of them and placed a living cat within the belly and left them alive thus, first cutting off their hands so that they should not be able to take the living cat out of the belly...and there was never an unnatural death in the world that they did not inflict upon them."

steve · 18 May 2005

Question for Finley or any other creationist around:

Do you believe that the existence of god can be scientifically proven?

"Rev Dr" Lenny Flank · 18 May 2005

'Scientific truth' is co-extensive with 'truth'; therefore, if science can't establish something, it can't be established.

Um, says who?

You?

JRQ · 18 May 2005

snaxalotl, Not sure what you meant by that...I think you may have misunderstood. Finley argued that the following statement is self-defeating:

"'Scientific truth' is co-extensive with 'truth'; therefore, if science can't establish something, it can't be established."

I said,

Isn't it extraordinary, then, that assuming the truth of an unestablishable proposition should seem so universally beneficial; that it so readily results in an illusion of objective progress . . . especially considering the same illusion does not result from assuming the truth of so many other propositions . . .

My point was that IF Finley is correct (i'm not convinved he is), then he should actually be MORE impressed that science seems to work so well. When I said it was extraordinary that "assuming the truth of an unestablishable proposition should seem so universally beneficial...", the unestablishable proposition was the one about science above that finley thinks is flawed. Science DOES certainly seem to result in objective progress whether the continued reliance on it to the exclusion of other things is justifiable or not. In Finley's epistemology, this must be an illusion. so he should find it quite striking that we get so powerful an illusion from assuming the above statement about science is true, when we do NOT get a similarly-powerful illusion from assuming other statements are true.

"Rev Dr" Lenny Flank · 18 May 2005

Finley argued that the following statement is self-defeating: "'Scientific truth' is co-extensive with 'truth'; therefore, if science can't establish something, it can't be established."

Finley's statement is, of course, an utter crock. I've never heard any scientist make any such claim. Just another ID strawman, which IDers need because they don't have any real science to present, and therefore must, like Finley, resort to profound-sounding pseudo-philosophical bullshit instead. (shrug) At least Finley has apparently given up on his several previous failed attempts to produce testible scientific statements using ID. But then, even an earthworm is capable of learning from experience. Perhaps there is hope for Finley after all, if he would ever stop contemplating his navel and spend some time in the real world.

Harq al-Ada · 18 May 2005

What on Earth did Michael Finley do to deserve such abuse? He has not promoted ID on this thread, or trashed evolution science, and more importantly, he was somewhat civil. He seemed to be defending nothing more than the idea that one can be a scientist and a believer.
When the argument between science and intelligent design becomes tangled with the argument between atheism and theism, the ID people win. Maybe the likes of Johnson and Dembski right, that most evolutionists are atheists looking for a way to impose their worldview on others, and that "theistic evolutionists" like me are just befuddled fence-sitters and closet ID believers.
I don't agree with this point, but it sure doesn't help when evolutionists seem to confirm it. Damn you Dawkins. I love your writing and your science, but can you keep your philosophy to yourself?

Don Sheffler · 18 May 2005

I couldn't see it anywhere here, what is the approximate age of the Dmanisi skulls?

Sir_Toejam · 18 May 2005

harq-

you haven't spent as much time watching finley's ridiculous attempts at philosophy hijack threads over and over again, obviously.

we judge him based on the hundreds of posts he has put up here, which always end in assertions that are either disingenuous or downright insulting. that he comes off as seeming "reasonable" from time to time(and he sure doesn't always) is the only reason folks keep falling for his trollishness.

Micheal Finley · 18 May 2005

STJ,

You could simply ignore me (as I believe Flint has done). It wouldn't hurt my feelings. It takes two to 'hijack.' Apparently you enjoy feeding 'trolls'.

Sir_Toejam · 18 May 2005

glad to see you admit it.

Sir_Toejam · 18 May 2005

"Question for Finley or any other creationist around: "

Flint has just grown weary of giving your crap credence any more.

I see others are starting to figure out your nothing but a creationist troll as well, finley.

JRQ · 18 May 2005

I was was visiting PT for a while before I started posting, so I've become familiar with Finley's style sort of from the outside.

I've generally found him reasonable, but I see where the frustration comes from...he want's a philosophical audience that will judge the quality of various logical analyses independent of the harsh realities of how to apply them to scientific problems. He seems more interested in what assumptions are valid or justifiable than what's useful, factual, or likely. At PT, he has the opposite: an audience that cares about what the facts are, how likely the various explanations are, and how useful a theory or research program is.

I wouldn't call him a troll, but I'd say if he wants more productive discourse here, he needs to consider his audience a little better and be more forthright in addressing thier concerns.

Michael Finley · 18 May 2005

I admit nothing (thus the use of scare-quotes). Your replies, as Flint's, amount to mere name-calling. Any fool can do as much.

I won the argument concerning science's a priori commitment of naturalism (e.g., burning bushes, etc.). The other side was reduced to arguing that well-established English words are meaningless.

I won the argument concerning beliefs that cannot be empirically verified. Flint, recognizing this, simply refused to answer my questions.

And I would have not difficulty defending Plantinga's argument against naturalism if anyone around here had enough philosophical training to even understand it.

In the face of such victories, my detractors have resorted to ad hominem replies.

Sir_Toejam · 19 May 2005

lol.

false victory claims are a sure sign of trolldom.

I only started coming after you when it became quite clear that you are, in fact, just a troll. I finally got sick of some folks giving you any credence whatsoever, and many of those folks, like Flint, no longer do.

you only seem to win these arguments in your own mind.

but, if you are convinced you have trounced us all, why are you still here? why don't you go back to greener pastures like the pee-wee playhouse over at Dembski's site?

think you are teaching us anything about logic or philosophy? your arguments are freshman level claptrap; I'd bet any philosophy dept. would have given you failing grades.

but, at least you seem happy in your own mind.

JRQ · 19 May 2005

I won the argument concerning science's a priori commitment of naturalism (e.g., burning bushes, etc.). The other side was reduced to arguing that well-established English words are meaningless. I won the argument concerning beliefs that cannot be empirically verified. Flint, recognizing this, simply refused to answer my questions. And I would have not difficulty defending Plantinga's argument against naturalism if anyone around here had enough philosophical training to even understand it.

I don't agree that you won these arguments. I think you made some points that were technically valid, but you were never able to establish why any of it mattered. IF science has a commitment to naturalism, so what? If beliefs cannot be verified, why does it make a difference that they are not verifiable? I saw no indication that anyone should care about the consequences of such things...now maybe that's because no one asked, or maybe you did address it and I didn't have the "philosophical training" to understand it...but the point never got across to me, and judging by responses from other, It didn't get across to them either. Again, if the points you think you've "won" are of import, we'd like to know why we should care. I'm just trying to be constructive here.

Harq al-Ada · 19 May 2005

Ah, I see. I lose track of names easily.

NDT · 19 May 2005

Why discuss philosophy on a biology site anyway?

Boronx · 19 May 2005

'Scientific truth' is co-extensive with 'truth'; therefore, if science can't establish something, it can't be established.

Except that this last statement is supposed to be true, and science can't establish it. Thus, the claim is self-defeating (i.e., self-referential incoherent).

Either your assumption is wrong, or your conclusion doesn't follow from your assumption, or your conclusion does follow, in which case you've established it through deduction.

But this is just one more example of why scientists who look at world have and should have more mindshare these days than philosphers who argue the meanings of phrases. Last I recall, "science" never tried to establish anything to 100% certitude. It's the difference between arguing Zeno's paradox and measuring tortoise speed with a stopwatch.

Jim Harrison · 19 May 2005

Horace wrote "you can expel nature through the door with a pitchfork, but she'll climb back in through the window." Philosophy isn't quite as fundamental as nature, but it's pretty nearly as hard to get rid of. Lord knows lots of people have tried.

Unless you're really going to maintain that 'Scientific truth' is co-extensive with truth,' a thesis that not even the positivists argued for, you're bound to have some sort of discourse that relates scientific truth to other kinds of truth and, while it's at it, relates truth to various other values. You can call that whatever you like, but you might as well call it philosophy and admit that it's going to be here for the duration.

Boronx · 19 May 2005

Of course, Jim, people aren't ruled by logic and scientific inquiry. In most judgements people make, scientific results at best merely inform, or have no input at all.

But this: 'Scientific truth' is co-extensive ( jargon for 'equates to' , right?) with truth,' is angels on a head of a pin territory.

And "...relates scientific truth to other kinds of truth". Is pure hogwash. What are "other kinds of truth"? What is scientific truth? Is there any such thing past "cogito ergo sum"?

What I see with modern students of philosphy is that they want to develop logical proofs without the rigourous definitions of Mathematics, and they want to divine the secrets of the universe without the empericism of Science.

Boronx · 19 May 2005

But this: 'Scientific truth' is co-extensive ( jargon for 'equates to' , right?) with truth,' is angels on a head of a pin territory.

Though I find this silly, I can't help but futiley weighing in on the argument by pointing out that a key element of Einstein's breakthroughs is the notion that if you can't measure something, then maybe it doesn't exist.

NastyLurker · 19 May 2005

'Scientific truth' is co-extensive with 'truth'; therefore, if science can't establish something, it can't be established. Except that this last statement is supposed to be true, and science can't establish it. Thus, the claim is self-defeating (i.e., self-referential incoherent).
— Michael Finley

because this thread has allready degraded to philosophical nit-picking, well, Just a question... except that hardly one really considers that statement to be true, how it's author came to the conclusion, that it can't be established scientifically ? I mean, let's imagine someone observes some examples of things considered to be 'true', and finds that all of them can be ( and most of them in fact have allready been ) established by science, so she states your 'co-extensive' statement as a hypothesis, and starts to testing it by searching for something that is quite sure 'true', but science cant't establish it. Meanwhile she develops some models of cognitive processes leading us to conclude that something is 'true', and finds their core very similar to some formulation of scientific method. And, after several years, and some ten thousand 'truths' checked for for scientific establishability, an no one found to be non-establishable, the statement would finally come to be a part of a scientific theory, so it is not scientifically non-establishable after all.

Brian Andrews · 19 May 2005

you're bound to have some sort of discourse that relates scientific truth to other kinds of truth

what other kinds of truth are you talking about exactly? Can you name one or hang it on a wall? Sounds like truth with a capital T. Is there really such a thing? I don't see how anything can be found to be true unless you can demonstrate it and evidence can be provided for it. And even then truth is a mirage waiting for the next demonstrated truth to supersede it.

Aureola Nominee · 19 May 2005

Michael Finley falsely claimed:

I won the argument concerning science's a priori commitment of naturalism (e.g., burning bushes, etc.). The other side was reduced to arguing that well-established English words are meaningless.

You lost that argument, Mr. Finley, when I showed you were utterly unable to give us an operationally useful definition of "supernatural" or of "god". You waved your hands and said "but of course everybody knows what God is", but a fine philosophical mind such as yours sure cannot fail to understand that your claim was unsupported. That is the definition of a defeat, not of a victory. Now back to reading more important things.

Heehee · 19 May 2005

"Did Lubenow steal the title and just replace “Controversies in the Search for Human Origins” with “A Creationist Assessment Of Human Fossils?”"

No, Lewin stole the title and replaced the subtitle.

"Rev Dr" Lenny Flank · 19 May 2005

What on Earth did Michael Finley do to deserve such abuse? He has not promoted ID on this thread, or trashed evolution science, and more importantly, he was somewhat civil. He seemed to be defending nothing more than the idea that one can be a scientist and a believer. When the argument between science and intelligent design becomes tangled with the argument between atheism and theism, the ID people win. Maybe the likes of Johnson and Dembski right, that most evolutionists are atheists looking for a way to impose their worldview on others, and that "theistic evolutionists" like me are just befuddled fence-sitters and closet ID believers.

I'm not an atheist. As for Finley, he's a typical ID bullshitter. He's already failed miserably to demonstrate any scientific content to ID, so now, like other IDers, he's taken to attacking the very basis of science itself by giving us lots of pseudo-philosophical crap about how unfair it is for science to exclude "supernatural explanations". Of course, he never seems to get around to explaining to us exactly how a "supernatural science" is supposed to work . . . .

"Rev Dr" Lenny Flank · 19 May 2005

I admit nothing (thus the use of scare-quotes). Your replies, as Flint's, amount to mere name-calling. Any fool can do as much. I won the argument concerning science's a priori commitment of naturalism (e.g., burning bushes, etc.). The other side was reduced to arguing that well-established English words are meaningless. I won the argument concerning beliefs that cannot be empirically verified. Flint, recognizing this, simply refused to answer my questions. And I would have not difficulty defending Plantinga's argument against naturalism if anyone around here had enough philosophical training to even understand it. In the face of such victories, my detractors have resorted to ad hominem replies.

Ahhh, the argumentum ad Saddam -------- get your ass kicked thoroughly, then run away and declare vicotry. Hey Finley, I'm still waiting for you to make a single scientifically testible statement about the world around us usign ID "theory". I'd also like to hear you explain to me which step of the scientific method requires or commits itselgf to philosophical naturalism. Oh, and it would help if you could explain why you think it's a bad thing for evolution to commit itself to naturalism, but not a bad thing for weahter forecasting, accident investigation, or medical science to commit itself to naturalism. What seems to be the problem?

"Rev Dr" Lenny Flank · 19 May 2005

Why discuss philosophy on a biology site anyway?

Because IDers have no science to present. All they have left is "you are philosophically biased against me, boo hoo hoo".

Savagemutt · 19 May 2005

Sorta on topic...

Is there any other benefit to having a big brain relative to body size other than what we would call "intelligence"? As I understand it, brains are energy hogs, so I wonder if there's some sort of "critical mass" for brain size where the benefits (if intelligence is the only real benefit) outweigh the energy costs.

Apologies if this is incoherent. The caffeine hasn't taken hold yet.

Russell · 19 May 2005

I wonder if there's some sort of "critical mass" for brain size where the benefits (if intelligence is the only real benefit) outweigh the energy costs.

I've seen what seems to me a plausible hypothesis: that brain size is limited by the difficulties it imposes on childbirth.

Flint · 19 May 2005

Savagemutt:

In Dawkins's book The Ancestor's Tale (which was doubtless taken from other material) there is a chart of brain size relative to body size. Humans are above average in this respect, but not at the top of the chart (graph, actually). However, brain mass is put to different uses irrespective of relative size. Consider that much (perhaps most) of a dolphin's brain is dedicated to controlling and interpreting sonar. Does this remarkable ability count as "intelligence"? It certainly seems to help them catch meals.

Sandor · 19 May 2005

What I have read is, that we leave the womb so early in our development to prevent problems with childbirth.

Furthermore, our brain is (one of the) the organ(s) most fully developed in size at childbirth. I am not sure if the same is true for other animals, but I bet it does, especially with mammals (that's what makes them look so "cute")

An unborn babie's skull is quite flexible bytheway, and will deform considerably while it is forced through the birth canal. I do not know how easily the brain can be deformed without causing damage, but I bet it can take quite a lot of abuse.

If natural selection worked in favor of an even more increased brain size at childbirth, I do not see any reason why this could not be established.

As far as energy consumption is concerned; if in principle it's possible for to body to evolve a more efficient way to deliver energy to the brain, then selection on this trait would create the possibility for a bigger brain to develop.

Maybe the limiting factor would be the fact that we get to top-heavy, in which case human's descendents might end up to look very much like Humpty Dumpty.

Savagemutt · 19 May 2005

Flint:

Ah, I didn't even think about other sense-processing functions. And this despite just having finished "The Blind Watchmaker" which discusses some of that.

Thanks for all the replies.

Jim Harrison · 19 May 2005

I wrote above that philosophy is inevitable because you can't get around the need to relate scientific truth with other kinds of truth. There's nothing mysterious about the idea. Notions of truth appear in many areas of human endeavour: everyday life, mathematics, history, law, ethics, aesthetics, and politics. It is very far from obvious, for example, how scientific results should be used in the context of trials or whether the kind of procedures and standards that apply in physics or biology tell us very much about art or music.

In my experience, attempting to dispense with philosophy merely guarantees that the philosophizing that nevertheless takes place will be done in a covert and amateurish fashion. Since it's going to be done by somebody, it might as well be done as well as we can manage.

By the way, these comments are not an attempt to promote the philosophy business, i.e. academic philosophy. Historically lots of interesting philosophy has been done by professional scientists and plenty of bad philosophy is done by philosophy profs.

David Wilson · 19 May 2005

In comment 30915

Gee, I thought "Bones of Contention" was a popular book by Roger Lewin about the history of paleoanthropology. Did Lubenow steal the title and just replace "Controversies in the Search for Human Origins" with "A Creationist Assessment Of Human Fossils?" I should look up a copy of Lubenow's book, but, in the meantime, does any know if he even references Lewin's book?
— Duane

In comment 31030

No, Lewin stole the title and replaced the subtitle.
— Heehee

Evidence? Judging from the entries in the Library of Congress catalogue, the first edition of Lewin's book came out in 1987, while Lubenow's didn't appear until 1992. So if either of them stole from the other, this would appear to indicate that it must have been Lubenow who did the stealing. But the title is a pretty obvious one for a book on palaeontological controversies anyway, so I don't see any reason too believe that either of them "stole" the title from the other, or from anyone else for that matter. If you do a title search for "Bones of Contention" in the Library of Congress catalogue at the link given above, you will find it has 8 distinct items with that title, the earliest of which is dated 1944. So if either Lewin or Lubenow did "steal" the title, there are plenty of other victims they could have stolen it from.

Boronx · 19 May 2005

Notions of truth appear in many areas of human endeavour: everyday life, mathematics, history, law, ethics, aesthetics, and politics.

I see your point is a practical one, my apologies.

Globigerinoides · 19 May 2005

"I've seen what seems to me a plausible hypothesis: that brain size is limited by the difficulties it imposes on childbirth."

If humans were "designed", why does the birth canal pass through the pelvis? Why couldn't large-brained babies be born without having to pass through a doughnut of bone? Think of the advantages if babies at birth could walk and had control of bowels and bladder!

According to IDists, dipes must be part of the Designer's Plan.

Henry J · 19 May 2005

Re "in which case human's descendents might end up to look very much like Humpty Dumpty."

Or Coneheads, like in the movie. ;)

Sir_Toejam · 19 May 2005

"Maybe the limiting factor would be the fact that we get to top-heavy, in which case human's descendents might end up to look very much like Humpty Dumpty."

Hmm. It would seem to me that if there were heavy selection pressures favoring large brain mass, why not seperate brain mass in multiple locations?

There are plenty of animals with multiple ganglion systems... why don't we see mammals with multiple brains?

If an organism is getting too "top heavy"... why not develop a brain in oh, say, the ass area?

I've heard some humans think with their stomach, and some males think with their d*cks... maybe brain seperation is already being selected for?

EmmaPeel · 19 May 2005

Hmm. It would seem to me that if there were heavy selection pressures favoring large brain mass, why not seperate brain mass in multiple locations? There are plenty of animals with multiple ganglion systems . . . why don't we see mammals with multiple brains? If an organism is getting too "top heavy" . . . why not develop a brain in oh, say, the ass area?
— Sir_Toejam

Ah, a redundant brain would be wonderful! That and a redundant heart, and I guess a redesign of the esophagus. There are some major design "decisions" that the "designer" made that show to me that this "designer's" goals were to produce something that's just good enough & no better. But, as for distributed brainpower: I once had surgery where they gave me an epidural drip, where they inject novicaine into the base of the spine. After I woke up & waited for the feeling in my legs to come back, I was bored out of my mind, not to mention all the phantom itching sensations that kept flaring up, presumably as individual neurons at the base of the spine woke up. So I desperately tried as hard as I could to move my toes, legs, anything - for god's sake, something!!! But at the instant that I actually tried to move something, the intense desire vanished! It wasn't that I was trying hard and the legs refused to obey; it was that the desire itself vanished. I take that to mean that our moment-by-moment sense of what our brains desire is intimately connected to the feedback we get from the rest of our nervous system. Since then I've concluded that some of our mind is, in fact, contained in the nervous system as a whole.

jeffw · 19 May 2005

Hmm. It would seem to me that if there were heavy selection pressures favoring large brain mass, why not seperate brain mass in multiple locations? There are plenty of animals with multiple ganglion systems . . . why don't we see mammals with multiple brains?

Actually we do (in a sense) have multiple brains - left and right hemispheres connected by the corpus calloseum. If a multiple brains were located elsewhere in the body, they would also need thick cabling to communicate. Then there is the issue of control & dominance, and how control would be distributed. And or course someone would come up with religious questions of "what does it mean to have a soul" in that context. In the future we may be able augment our nervous system through technology. That would also have philosophical & religious implications. But in evolution, there has to be some way to get there from here. I suspect the genotypic distance separating the two designs may be too great to permit that kind of change.

St. McHinx · 19 May 2005

Philosophers start with paper and a pencil.

Scientists start with paper, a pencil, and a garbage can.

"Rev Dr" Lenny Flank · 19 May 2005

If humans were "designed", why does the birth canal pass through the pelvis?

Haven't you read the ID, uh, scientific textbook yet? Human birth is so difficult because a woman several thousand years ago was tricked (by a talking snake) into eating a magic fruit, and as a result her descendents were cursed forever and ever and ever. Or something like that . . . . .

JRQ · 19 May 2005

why not seperate brain mass in multiple locations?

Costs in speed of transmission over a now-longer distance would potentially slow higher-level information processing way down. Cognitive inhibition in particular would be a big problem if it took too long.

Sir_Toejam · 19 May 2005

JRQ:

hmm. that's as good an explanation as any. Anyone here ever run across any tests of the potentially slower info processing?

@lenny

your post about original sin reminds me of the Davinci Code.

ever read that one? The guy gives a very plausible explanation of the development of the idea of original sin, and male dominance in christian churches (especially Catholic).

It was quite a refreshing change of pace from the standard "revelation style" religion-based action/mystery novels. A work of fiction to be sure, but like a good sci-fi novelist, the theories he develops to back the plot are quite plausible, and contain quite a bit of fact. A good read if you haven't.

Globigerinoides · 19 May 2005

"Haven't you read the ID, uh, scientific textbook yet?"

Oh! Silly me. I thought ID wasn't supposed to be tied to any particular sect, but just postulates some generic Designer.

Never mind.

outeast · 20 May 2005

Loved this article! I hadn't read about the dmanisi skulls before... Actually, I liked it so much I've bought the dmanisi.org domain. Any bright ideas for what to do with it?

Sir_Toejam · 20 May 2005

interesting...

I've seen several requests for good displays of skulls, fossil hominids, up-to-date diagrams of current theories of humanoid descent, etc.

I suggest making it a repository of visual aids for common descent theory.