Thursday 30 August 2012

This Bears Repeating: Dunsworth et al.'s 'Metabolic hypothesis for human altriciality'

This would have been inconceivable forty years ago. And, if the results hold up, it's an intuitively satisfying explanation for why we're born helpless, and remain so for many months post-partum. A tip o' the hat to Erin Wayman for alerting us to this story.
     Using biomechanical studies in tandem with the metabolism of pregnancy Dunsworth et al. have ruled out birth canal size as the limiting factor where gestation length is concerned. Instead they posit an energetic equation whereby the pregnant female is constrained to give birth at around nine months by her body's inability to produce the energy necessary to maintain her life and that of her foetus. Brilliant concept! It's a good day to be a palaeoanthropologist.


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Monday 27 August 2012

Monday Morning Mirth

Genius. Pure Genius.
This one goes out to Meg.
From the Saturday Morning Breakfast Cereal


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Possibly an Act of Desperation. We'll See... Rule #1 Applies Here

It had been a brutally hot summer, and the earth looked as if it had been scorched even before dry lightning ignited the wilderness. The devastation covered over a million hectares. The same gray landscape stretched beyond the horizon in every direction. Blackened, leafless trees stood silent watch over nothing. No birds. No ground dwellers. Not a plant. Not a single living thing, save for the three bipedal creatures making their way up the dry valley. 
     There had never been much water in this region, where streams suddenly disappeared beneath ground, and elsewhere emerged from gaping holes in the rock. The three were stumbling up the steep hillside. Their breath was rasping, and they frequently coughed. One was spitting blood after each paroxysm of coughing. The smoke had been thick in the air for weeks as the world around them was slowly and inexorably consumed by the fire. Now they were debilitated by it, and they needed to stop often to catch their breath. 
Photo source
     They had survived the summer before the fire because there'd been many drought deaths amongst the animals in their range, and having a decent olfactory sense the three knew where to look for a feed. Precious water was available in the dead one's gut. But now even the carcasses were inedible, and whatever water their tissues once had held was either too meagre or so befouled as to make it worse than unpalatable. They seemed to be the only things moving on the landscape. And in truth they were. They alone had survived the fire because they knew the location of many holes in the rock, and had sheltered in one while the fire had burned outside. There had been a small seep in the wall of the fissure in which they'd huddled, and it had been enough to sustain them until it was possible to move about outside the hole.
     At first they could find grass seed and nuts, survivors only because of the their hardened outer coverings. Day after day they combed the ground for the insubstantial rewards. Their saving grace was no doubt that they expended little energy and never moved very far from their den. As they depopulated one area after another of the seeds and nuts, they moved further away from the hole in their search.  
     Now, at the top of a ridge the three stopped, then stooped and began scraping at the dirt with the stones that each carried. Here and there they could see the charred tops of edible tubers that had been growing just beneath the surface. The three ate ravenously whatever was left of the acrid, starchy roots, as they had now done for more than a month since the ground had cooled enough to make walking possible. They would need to return to the hole each day, since it was the only place they could get water. Without water the end would come swiftly.
     Instead the end would come slowly for the three, and in all likelihood they would die in the hole that had given them a reprieve from the inevitable. 
     
I know that the foregoing could easily be construed as a desperate act, considering that I've failed in my efforts to discover alternative natural sources for the organic compounds found in the dental calculus of the El Sidrón hominids. This left me wondering as to the possible natural circumstances under which those Neanderthals could have inhaled sufficient wood smoke for it to be recorded in the calculus adhering to their teeth, and have ingested quantities of cooked, starchy vegetables with the same effect. 
     I believe that the word picture I've painted here, rather than being the desperate act of a beaten skeptic, is not just possible or plausible, but must have been experienced by hominids throughout history. The degree to which they could survive such devastation would've been determined to a large degree by the areal coverage of the wildfire. Too widespread and the bipeds couldn't have weathered the vicissitudes of the natural world.
     Remember Rule #1: Rule out the natural before imputing your observations to the actions of bipedal apes.


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Saturday 25 August 2012

The Paleo Diet and the Question of Cooking at El Sidrón Boils Down *cough* to n-alkanes. Who Could've Predicted?

Allright! Allright! I was wrong. The last words out of my mouth on this matter were that they would be my last words on the matter. Well, I was wrong. 
     I'm talking about the Neanderthal dental calculus chemical characterization undertaken by Stephen Buckley, and which was published under the title of 'Neanderthal Medics?' [catchy title] by Hardy et al. 2012. Certain organic compounds led the authors to infer that cooked vegetables were the source. Neanderthal chefs?
     Stephen was kind enough, and a responsible enough scientist [are you listening, all who're guilty of avoiding the Subversive Archaeologist?], to confront my suggestion that he and his colleagues may have overlooked some alternative sources for the organic compounds they found adhering to the El Sidrón Neanderthals' teeth [in the form of calculus--hardened plaque]. His comments on my previous attempts, herehere, and  here, are to be found by clicking here, here, and here. [It's all enormously edifying and entertaining. You should go.]  
     Today Stephen responded to what was to have been my last word, and in his characteristically mild and amicable way, he acknowledged that insects do indeed produce hydrocarbons. Then he said something odd. Even after I quoted from a scholarly paper that mentioned finding 'a homologous series of n-alkanes (n-C21 to n-C31) [graphically cited below],

Would I Lie to You? Click here for web access.

Stephen, maven of mass-gas chromato-stratigraphic-oscopy [or something equally unpronounceable and technically so far beyond my abilities as to be completely embarrassing ], states that insects are capable of producing hydrocarbons [well known to everyone else, it would seem, besides me], however 
'...[insects] are usually accompanied by branched alkanes and alkenes too – you actually quote these in your piece. Plant wax esters, on the other hand, produce n-alkanes (and n-alkenes – these are often absent in archaeological samples, where they have undergone decay)...' [comment on Buzz Off!]
'Bummer,' I said to myself. Another beautiful theory bapped in the face by a brutal fact. I was just about ready to slink off and back into the intertubes where I belong, when it hit me. Not the fact; the anomaly. Stephen was writing as if the species of parasitic wasp about which my article was talking contained only 'branching' alkanes. ]The anomaly, by the way, is that Stephen seemed to be making a rare slip.] 'What's up with that,' I asked myself. [Such protracted conversations with myself are occurring with frightening regularity, nowadays. Maybe I'm spending too much time alone. Ya think, Rob?] 
     So, I went to check. There they were. Branching alkanes. [Who'd've thought this archaeologist would one day find himself talking about branching organic molecules?] Undaunted [or so I'd want Stephen Buckley to believe] I soldiered on. And, my perseverance paid off. I wasn't imagining it! That pesky wasp was making n-alkanes, too. 'What a trooper,' I thought to myself [more concerned, this time, that I was personifying a wasp than that I was talking to myself again]. I have the proof right here. And, it's even more exciting than I thought it was the first time!
     Immediately below I'm reproducing the table showing the actual values, by weight, of each of the compounds that were found in the wasps' Dufour glands. BEFORE you go all weird about the size of the type, chill. The table is just for show. I'll extract the important data for you. But don't be surprised by the miniscule quantities reported. Wasps are small, mind you. So their little Dufour glands don't hold much of anything--according to this table, ~332 nanograms of organic compounds [that's billionths of a gram to the SI-challenged among you]. The truly gloatable bit from this table is that ~30% of the stuff in each gland comprises...you should be sitting down, Stephen...n-alkanes. They run the gamut from n-C21 through n-C31. 30% by weight! Wriggle out of that one, Mr. biochemically savvy El Sidrón dental calculus man! 
Not bad, eh? Perhaps those El Sidrón Neanderthals weren't eating cooked plants after all. [crickets chirping]
     Moving on. Even if the vegetable-cooking inference of Hardy et al. falls flat on its face when faced confronted by the alternative, my efforts haven't made so much as a dent in their other major conclusion--that the Neanderthals were inhaling a lot of wood smoke. Gimme a break! I'm workin' on it. Let's see... Those Neanderthals prolly expired from smoke inhalation while huddling in their cave until the palaeo-firestorm was over, only the cave just concentrated the smoke and bits of it got stuck to the teeth of the Neanderthals, who were by think time gasping, mouths agape, for the last nanogram of breatheable air... [Hey, I'm allowed to make up stuff, too! Ain't I?]
      
     I'd like to acknowledge the patience and persistence that you're demonstrating, Stephen, in this protracted conversation with a total know-nothing-about-organic-chemistry type. Thanks. As for the other stuff--philosophy and absent evidence and all that--maybe some day soon we can sit down over a pint No! a Pimms No. 1 Cup in the back garden at the Wheat Sheaf in Oxford. That'd be perfect. Later.


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That Wild and Crazy Casey Luskin Uncorks Another Beauty: Makes Monkeys Out of Professional Palaeoanthropologists

In the beginning was the Word, and the Word was with God, and the Word was God. [1 John 1:1]
I'm beginning to get a sense of the problem. When approaching the voluminous literature of human evolution Young Earthers and Creationists/IDers [i.e. Intelligent Design adherents] can't get past the habit of believing that [at least some of] what they read as being the revealed word of a deity. As such my colleagues could afford to be a bit more careful when choosing their words. I can easily see why their best efforts feed into the Christian creation myth.
     Notwithstanding his propensity to treat the writings of us as the word of a deity revealed [much like my colleagues come to think of it], Luskin is either very lucky and came up with the foundation for his argument by chance or the man has done his homework and read widely in 'our' literature. Such is his virtuosity.
     Shortly before leaving for the Czech Republic in July I felt preternaturally compelled to write about the efforts of Casey Luskin, a lawyer and IDer. At that time he was promising a whole series of tell-all revelations that he reckoned would dissolve the humanist edifice that is our present knowledge of the fossil record. As I now discover, in the interim I've missed many more articles by the prolific Mr. Luskin. No worries! The SA news ticker came to the rescue the other day when up popped this: 
THE GENUS HOMO: ALL IN THE FAMILY
Luskin's major point is a variation of the theme of the earlier article. Australopithecus is an ape; Homo is a human. Read on to find out how he makes monkeys out of my colleagues. 
     I could give Luskin's whole spiel a pass were it not for the way in which he artfully weaves the words of our colleagues into a narrative that underscores his conclusion--that the appearance of Homo in the fossil record isn't prefigured by the earlier australopithecines, and is thus strong evidence of the special creation of humanity. Of course, to do so he must paint all members of the genus Homo in such a light that 'we' all appear to be like modern humans. And that's where where my colleagues come in--aiding and abetting Luskin and his ilk with authoritative statements such as the ones included in the medley of the following Luskin quotes [complete with a very scholarly looking list of references cited]. 
'Donald Johanson suggests that were erectus alive today, it could mate successfully with modern humans to produce fertile offspring.' [from Lucy]
'Wood and Collard [reinforce the similarities among members of our genus when they write]: "The numerous associated skeletons of H. neanderthalensis indicate that their body shape was within the range of variation seen in modern humans." ' [That wouldn't be you, Mark, would it?] [published in Science]
 'Erik Trinkaus likewise argues: "They may have had heavier brows or broader noses or stockier builds, but behaviorally, socially and reproductively they were all just people." ' [From an interview in Time]
'Trinkaus and others say there is no reason to believe they were any less intelligent than the newly arrived 'modern humans.' ' [Washington Post interview]
'Fred H. Smith [adds in a Smithsonian interview] "[The first European palaeoanthropologists] believed [Neanderthals] to be scavengers who made primitive tools and were incapable of language or symbolic thought." Now, ... researchers believe that Neanderthals "were highly intelligent, able to adapt to a wide variety of ecological zones, and capable of developing highly functional tools to help them do so. They were quite accomplished." '
'Francesco d'Errico affirms these comments [in the same Smithsonian article], stating, "Neanderthals were using technology as advanced as that of contemporary anatomically modern humans and were using symbolism in much the same way." '
My dear old friends from the Kebara Cave project add fuel to this fire: ' "the morphological basis for human speech capability appears to have been fully developed" in Neanderthals.'
'Neanderthals made musical instruments like the flute.' [citing the debunking article in Current Anthropology, as it happens]
'a report in Nature from 1908 that reports the discovery of a Neanderthal type skeleton wearing chain mail armor.' [from Notes in Nature, 77 (April 23, 1908): 587, see below.]
[At least Luskin owns up to the preceding two inferences being somewhat 'uncertain'--would that my colleagues were so circumspect.]
'Trinkaus says that when comparing ancient Europeans and Neanderthals: "Both groups would seem to us dirty and smelly but, cleaned up, we would understand both to be human. There's good reason to think that they did as well." ' [Another humdinger from the Washington Post article cited above]
Plunging the knife in even a tad further, Luskin then cites the recent DNA 'evidence' that Neanderthals R Us and vice versa. I don't have to tell you what I and a few others think of those tasty inferences. The author finishes the medley of incriminating statements with: 'We saw earlier that Leslie Aiello said "Australopithecines are like apes, and the Homo group are like humans." ' [Shame on you Leslie Aiello. You of all people should know that you can't split the ape family/superfamily into us and them.]

I ask you. How can we expect to gain credibility with the supernaturalists when we so readily feed their doctrinal belief that humans aren't apes?  At every chance we should be reminding them that humans are nothing if not apes. That oughta get 'em thinking.
     So, let's all get on the same page and stop these people from making monkeys of us all! 



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Buzz Off! Can't You See I'm Up to My Ears in the Organic Chemistry of El Sidrón's Dental Calculus???

Hmmm. I've been struggling with Stephen Bradley's comments on my recent post about Neanderthal oral hygiene at El Sidrón. Throughout he has maintained that the most likely source for the chemical constituents revealed by sophisticated mass spectrometry is wood smoke and cooked food. I have tried to suggest alternative natural sources of some of the compounds that he and his co-authors have identified.
     I would be dead in the water after his protracted comments on my earlier efforts were it not for my determination both to overcome my substantial ignorance of organic chemistry and to extend my argument beyond Stephen's assertions and, indeed, his conclusions. I'm having some success, I think. Take, for example, his insistence that alkenes and alkanes are plant waxes: 
The thermal desorption-GC-MS (TIC) (Fig. 1 inset) is dominated by a series of n-alkanes (carbon numbers C22 to C35), suggesting a higher plant source (Eglinton et al. 1962), most probably derived from plant waxes in the original food consumed.
I'll ask Stephen or some other organic chemist to adjudicate whether or not I've discovered another natural source of these chemicals--insects. Here is a snippet regarding the Dufour gland of a wasp, Habrobracon hebetor (Say) (Hymenoptera: Braconidae). 
The hydrocarbons consist of a homologous series of n-alkanes (n-C21 to n-C31), a trace amount of 3-methyl C23, a homologous series of internally methyl-branched alkanes (11-methyl C23 to 13-methyl C35), one dimethylalkane (13,17-dimethyl C33), a homologous series of monoenes (C(25:1) to C(37:1)) with the double bonds located at Delta9, Delta13 and Delta15 for alkenes of carbon number 25 to 31 and at Delta13 and Delta15 for carbon numbers 33 to 37 and three homologous dienes in very low amounts with carbon numbers of 31, 32, and 33. [emphasis added]*
I realize that eating insects isn't as sexy as eating cooked plants, specially not wasps. But it's not just wasps. A quick check suggests that hydrocarbons of all kinds are naturally occurring substances in insects. And it wouldn't be the first time that a primate was 'caught' eating insects. I've eaten crickets many times at sushi bars.
     I don't think I'll continue in this vein, trying to ferret out alternatives to Hardy et al.'s inferences. At this point I'd just like to chill on my veranda with a cold one.
     But not quite yet. This business with the El Sidrón Neanderthals' dental calculus has made me think about the assumptions that Stephen Bradley owned up to--that as far as he knows the Neanderthals made fires and cooked food and did numerous other things that you and I might do. I think otherwise.
     I don't know which is worse: me, having lived with the Middle Palaeolithic archaeological record for going-on 30 years and spending all my time trying to pierce the inferential balloons that my colleagues set free to ascend to the scholarly firmament, or earnest peers like Stephen Buckley having taken breath from those same balloons as a matter of course in their intellectual upbringing, spending all their time inadvertently adding to the cloud of colourful spheres floating above our heads. Whadda you think? I know what I think. I think this calls for me to touch on a subject near and dear to my heart in the near future--the context of discovery versus the context of justification (or verification). I've often been accused of being 'unscientific' because I start from the assumption that the Neanderthals were dummkopfs. So, stay tuned.
Arch Insect Biochem Physiol. 2003 Nov;54(3):95-109. Novel diterpenoids and hydrocarbons in the Dufour gland of the ectoparasitoid Habrobracon hebetor (Say) (Hymenoptera: Braconidae). Howard RW, Baker JE, Morgan ED.

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Wednesday 22 August 2012

Whether You Call Yourself Christian, or You're a Militant Christian, Christian Supremacist, or Christian Extremist, You Should Take a Long Hard Look at This.

This morning on the Subversive Archaeologist's news ticker I spotted this article on HuffingtonPost.com. The Academic, Charles Negy (University of Central Florida) was compelled to write an email to his students emphasizing something he was attempting to teach in a psychology class he was leading. I copy it here, verbatim, because I believe that it represents a fundamental anthropological insight--which abhors ethnocentrism--and because I believe the further that this gets on the intertubes, the better.
Charles Negy, Professor, Says Students Showed 'Religious Arrogance And Bigotry'
Hello, Cross-Cultural students, I am writing to express my views on how some of you have conducted yourself in this university course you are taking with me. It is not uncommon for some-to-many American students, who typically, are first-generation college students, to not fully understand, and maybe not even appreciate the purpose of a university. Some students erroneously believe a university is just an extension of high school, where students are spoon-fed “soft” topics and dilemmas to confront, regurgitate the “right” answers on exams (right answers as deemed by the instructor or a textbook), and then move on to the next course.Not only is this not the purpose of a university (although it may feel like it is in some of your other courses), it clearly is not the purpose of my upper-division course on Cross-Cultural Psychology. The purpose of a university, and my course in particular, is to struggle intellectually with some of life's most difficult topics that may not have one right answer, and try to come to some conclusion about what may be “the better answer” (It typically is not the case that all views are equally valid; some views are more defensible than others). Another purpose of a university, and my course in particular, is to engage in open discussion in order to critically examine beliefs, behaviors, and customs. Finally, another purpose of a university education is to help students who typically are not accustomed to thinking independently or applying a critical analysis to views or beliefs, to start learning how to do so. We are not in class to learn “facts” and simply regurgitate the facts in a mindless way to items on a test. Critical thinking is a skill that develops over time. Independent thinking does not occur overnight. Critical thinkers are open to having their cherished beliefs challenged, and must learn how to “defend” their views based on evidence or logic, rather than simply “pounding their chest” and merely proclaiming that their views are “valid.” One characteristic of the critical, independent thinker is being able to recognize fantasy versus reality; to recognize the difference between personal beliefs which are nothing more than personal beliefs, versus views that are grounded in evidence, or which have no evidence.Last class meeting and for 15 minutes today, we addressed “religious bigotry.” Several points are worth contemplating:Religion and culture go “hand in hand.” For some cultures, they are so intertwined that it is difficult to know with certainty if a specific belief or custom is “cultural” or “religious” in origin. The student in class tonight who proclaimed that my class was supposed to be about different cultures (and not religion) lacks an understanding about what constitutes “culture.” (of course, I think her real agenda was to stop my comments about religion).Students in my class who openly proclaimed that Christianity is the most valid religion, as some of you did last class, portrayed precisely what religious bigotry is. Bigots—racial bigot or religious bigots—never question their prejudices and bigotry. They are convinced their beliefs are correct. For the Christians in my class who argued the validity of Christianity last week, I suppose I should thank you for demonstrating to the rest of the class what religious arrogance and bigotry looks like. It seems to have not even occurred to you (I'm directing this comment to those students who manifested such bigotry), as I tried to point out in class tonight, how such bigotry is perceived and experienced by the Muslims, the Hindus, the Buddhists, the non-believers, and so on, in class, to have to sit and endure the tyranny of the masses (the dominant group, that is, which in this case, are Christians).The male student who stood up in class and directed the rest of the class to “not participate” by not responding to my challenge, represented the worst of education. For starters, the idea that a person—student or instructor—would instruct other students on how to behave, is pretty arrogant and grossly disrespects the rights of other students who can and want to think for themselves and decide for themselves whether they want to engage in the exchange of ideas or not. Moreover, this “let's just put our fingers in our ears so we will not hear what we disagree with” is appallingly childish and exemplifies “anti-intellectualism.” The purpose of a university is to engage in dialogue, debate, and exchange ideas in order to try and come to some meaningful conclusion about an issue at hand. Not to shut ourselves off from ideas we find threatening.Universities hold a special place in society where scholarly-minded folks can come together and discuss controversial, polemic, and often uncomfortable topics. Universities, including UCF, have special policies in place to protect our (both professors’ and students’) freedom to express ourselves. Neither students nor professors have a right to censor speech that makes us uncomfortable. We're adults. We're at a university. There is no topic that is “off-limits” for us to address in class, if even only remotely related to the course topic. I hope you will digest this message, and just as important, will take it to heart as it may apply to you.Charles Negy
It occurs to me that those students for whom this email was intended ought to be attending Liberty University, or Oral Roberts. They'd feel and be more at home at either. And, it would leave space in the classroom for people who're genuinely interested in a liberal education. There's a reason they're called the Liberal Arts!
     As for the title. I make no apologies for the broad brush approach. I say this because it's my feeling that the bigotry alluded to in Negy's email is the very essence of Christianity, and is deeply rooted in the other Abrahamic religions, Judaism and Islam. 
Thou shalt have no other gods before me. 
Kinda sums it up nicely. Don't you think? 
'Scuse me. Tourette's moment coming.
POPPYCOCK!


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Germane. Timely. Appropriate. That's The Subversive Archaeologist!

http://phys.org/news/2012-08-science-threatens-person-world-view.html#nwlt

It appears as if there's a reason that my commentaries on archaeological inference-making often [mostly?] fall on deaf ears. From PhysOrg and University of Queensland.
'UQ Global Change Institute research fellow John Cook said reporting evidence that is perceived to threaten a person's view of the world can actually backfire. “People derive a large part of their sense of identity from their world view, how they see the world. So they react defensively to any information that threatens their world view,” he said. “What's fascinating, is that new, contradictory evidence can actually cause people to feel stronger in their initial beliefs.” Mr Cook, the mastermind behind the successful Skeptical Science website, is developing a psychological model that simulates how people react to evidence that threatens their world view. One of the features of the model is that distrust of science is a key factor in the so-called “backfire effect”. “If you distrust the science that threatens your world view, then more scientific evidence will make you react with suspicion, causing you to double down on your beliefs,” Mr Cook said. Mr Cook hopes the model will shed light on how people process information and give way to better, more effective approaches in science communication. “If distrust in science is a key element to denial, maybe we're better off targeting trust in the science - by explaining the peer-reviewed process and the checks and balances in the scientific method,” he said. Mr Cook's model, however, predicts that this approach will have minimal impact at the extreme end of the ideological scale. “When people have extreme views, you can't pull trust one way and world view the other. By and large, world view wins,” he said. “A better tack is to attempt to reduce the biasing influence of the world view, by showing that science doesn't threaten it.” According to Mr Cook's model, this works better when delivered by someone that shares the values of the recipient.'
Live and learn.



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Monday 20 August 2012

Pyrene, Good Night, Pyrene...With Apologies to the Immortal Lead Belly

Huddie William Ledbetter (January 20, 1888 – December 6, 1949)

[Update: Stephen Buckley continues his riposte in the Comments. Just click on the link at the foot of this post. 2012.08.21]

The other day I wrote about fact-checking Hardy et al.'s recent treatise 'Neanderthal Medics?' I pointed out that there was no substantive reason to accept their claim that the presence of four carbon compounds--flourene, fluoranthene, pyrene and phenanthene--implied that the El Sidrón Neanderthals had inhaled wood smoke. 
     Tonight I'd like to take up another of their conclusions, that several other chemical compounds indicated the presence, in dental calculus, of bitumen or oil shale. I should remind you that dental calculus largely comprises dead oral bacteria. As the authors put it
Also identified were a series of hopanes (carbon numbers C29 to C33), indicative of an oil shale or bitumen and corroborated by the presence of the isoprenoid hydrocarbon biomarkers phytane and pristane ... (p. 620)
Hopanes? Hopanoids. According to my favorite encyclopaedia, Wiki, the main function of hopanoids 'is to improve plasma membrane strength and rigidity in bacteria.' Hmm. Bacteria. Arrrr, Jim. Bacteria be the creaturs that make the biofilm that forms dental plaque, first off, and then calculus. Arrrr. It may well be the case that hopanes occur in bitumen or oil shale, but that may well be because both substances are the end-product of organic decomposition, decomposition that would in all likelihood have involved bacteria and other microorganisms. 
     'Pristane is a natural saturated terpenoid alkane obtained primarily from shark liver oil, from which its name is derived (Latin pristis, "shark"). ... It is also found in mineral oil and some foods. Biosynthetically, pristane is derived from phytol.' Among other sources of phytol, '... [i]n ruminants, the gut fermentation of ingested plant materials liberates phytol, a constituent of chlorophyll, which is then converted to phytanic acid and stored in fats.' Phytane is a diterpenoid alkane that's formed by the breakdown of phytol. 
     Granted, as Hardy et al. mention, these are all products that might be found in bitumen or oil shale. But, as I've pointed out, there's nothing unambiguous about the source of these compounds in the Neanderthal dental calculus at El Sidrón. And, for all we know, the (stable isotopically characterized) carnivorous Neanderthals, along with the meat and connective tissue, were consuming the contents of the rumen of their prey, much in the way the !Kung men on the hunt once did as a way of acquiring water where none occurred on the landscape.
     I find it really hard to believe that the editors of Naturwissenschaften gave more than a second's thought to the authors' interpretations, so taken must they have been by the study's results. After all, it's not every day that you get to see a report based on sequential thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS) and pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS), such as that of Hardy et al. Only problem is, when an archaeologist fails to rule out natural occurrences before imputing Neanderthal behaviour, it's like popcorn without butter. It's indigestible.
     For my part, I'll go back to imagining the Neanderthals occasionally inhaling the smoke of wildfires, and waiting for extinction while they fed on whatever they could of the animals they brought down or scavenged.
     Do I really need to go on in this manner? Or, have I satisfactorily demonstrated the wrong-headedness of Hardy et al. I don't see the point. Anyone care to take the wheel?
    
     
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Sunday 19 August 2012

Drop Dead! One Of These Days I'm Really Gonna Lose It! Sima de los Huesos Was a Cemetery????

Did he fall? Was he pushed? Or, did he jump?

If I didn't know it was a story from Spain I'd have to say that this is truly *cough* galling!
 El hallazgo de la falange de un niño en esta campaña ha venido a reforzar la teoría que manejaban los investigadores de que la Sima de los Huesos alberga un santuario en el que se realizarían ritos funerarios. «Se trataría del primer santuario de la humanidad», explicó Arsuaga, quien argumentó que no existen restos en toda Eurasia de este calibre. «Es la prueba más antigua de un comportamiento funerario y de una acumulación colectiva», recalcó.
The short paraphrase is this: according to its excavation team, northern Spain's extremely well known hominid site, Sima de los Huesos, near Atapuerca (Burgos, Castile and León), is rife with the remains of Homo heidelbergensis [or H. antecessor, if you prefer] because it was the site of ritual disposal of the dead! Make. It. Stop. Please!
     It's been said before, of course, and lately it has sparked Sheffield's Paul Pettitt to invoke no end of totally untestable hypotheses about the 'evolution' of mortuary behaviour. And, of course, the media everywhere love to report spectacular archaeological claims. But what are we talking about, here? Graves? Tombs? A mausoleum? Perhaps a columbarium? Well, no.

That's gotta hurt!


     In fact, the circumstances of deposition can easily be guessed by translating the site's name into English. The word 'sima' en Español means, variously, abyss, chasm, or deep fissure]. And the phrase 'de los huesos' means 'of the bones.' Yes, subversive archaeologists everywhere, the Sima de los Huesos is what's commonly called, in palaeontological circles, a natural trap.

Journal of Human Evolution (1997) 33, 109–127

What's the archaeologist's 'prime directive'? That's right. Make every effort to rule out natural causes before imputing the observed phenomenon to hominid behaviour. So. Have J.L. Arsuaga et al. attempted to rule out natural processes? Hardly. They might as well claim that the thousands of cave bear and other animal bones were disposed of in a ritual fashion. I dunno...maybe they have already. Talk about myth-making in archaeology!
     I'm outa here.

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Saturday 18 August 2012

Spoilers! Next Up: Hardy et al.'s "Neanderthal medics? Evidence for food, cooking, and medicinal plants entrapped in dental calculus"

Phenanthrene
Fluorene


Pyrene
Fluoranthene

[Update: Please have a look at the four-part response from the biologist who undertook the chemical composition study of the El Sidrón Neanderthal's dental calculus. It's in the comments, at the foot of this post. 2012.08.21]

You may be wondering why I didn't jump on this when it was first announced. Published online on July 18 Hardy et al. claim to have extracted *cough* hard evidence of Neanderthal behaviours akin to those of modern humans from the dental calculus that formed on the teeth of 5 individuals from the Iberian Peninsula.
     I've been waiting for the time to look in detail at their claims, and although I haven't finished the fact-checking, I can say that Hardy et al.'s inferences are looking awfully shaky. As before when Very Serious Archaeologists have published chemical analyses, my focus is the authors' interpretation of their findings. I'll give but one example of this from their paper.
     They claim the following:
The additional presence [in the calculus] of the main combustion markers, fluorathene [sic], and pyrene, along with smaller amounts of fluorene and phenanthrene, strongly supports the evidence for cooking/smoke inhalation in this sample (621).      
For this exciting discovery they cite two studies: one on the chemicals produced during charcoal production, and the other on smoked salmon. Seems reasonable. No? Well, not really.
     Pyrene and fluoranthene are the products of combustion, it's true. However, they are characteristic of incomplete combustion, i.e. combustion in a reducing atmosphere--one in which there is insufficient oxygen for complete combustion to occur. That describes perfectly the 'cooking' environment only if you're producing charcoal or, indeed, smoked salmon. Phenanthrene is found in tobacco smoke and that of coal-burning appliances. Fluorene occurs naturally, and according to the EPA, '[f]umes from vehicle exhaust, coal, coal tar, asphalt, wildfires, agricultural burning and hazardous waste sites are all sources of exposure.'
     Now, remember that it was the authors' intention to produce evidence for cooking, fire, and plant use. Their inference here--that the Neanderthals were inhaling smoke-- depends entirely on the erroneous claim that the four compounds are present in the Neanderthal's dental calculus because of smoke inhalation. I have to ask, 'How likely is it that this group of Neanderthals inhaled smoke from charcoal production or salmon smoking in a reducing environment, tobacco smoke, vehicle exhaust, or hazardous waste?      
     I think you can guess the answer to my rhetorical question. But that doesn't address the possibility that the Neanderthals in question weren't dry-distilling birch or coal tar, and sniffing asphalt. After all, as the authors remind us others have made claims that Neanderthals were capable of dry-distilling birch tar and using asphaltum to haft points on wooden shafts. Why couldn't these Neanderthals have been doing just that? 
     I suppose they could have been dry-distilling birch or coal tar (if either Betula or coal were components of the El Sidrón environment--an open question at the moment). Except, if so, they'd have been inhaling the smoke from the wood fires used to 'cook' the two substances, rather than inhaling any of the compounds given off while the birch or coal were 'cooking,' because it's necessary to keep the substances being 'cooked' in hermetically sealed vessels throughout the process! Likewise, they might have been inhaling asphaltum while they were gluing a rock to a stick. But...well, I think you get the point.
     And the point is this. The authors have done nothing, not a thing, to rule out the natural sources of the chemicals they report on. And that is a subversive's take on but one of the claims made by Hardy et al. I'll have more on this cockamamy paper in a subsequent post.


     
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Friday 17 August 2012

Google Street View at Tulum (For Example)

 Nothing short of amazing.

Street View courtesy of Google Earth.

 The Washington Post: 
"Google using 3-wheeled bike to add panoramic views of Mayan ruins to ‘Street View’ feature"
Go ahead. Open Google Earth and search for Tulum, Mexico. Do a little coastal survey and drill down when you see the little evergreen tree that denotes the archaeological ruins. Then drag the Street View icon over it and amazement follows. I've never been to Tulum. Now I won't feel like I've missed it.
     If I could afford one, I think I'd go and buy a share of Google right now!



Must Be A Slow News Day! 'Mayans may have sacrificed ancient domestic turkeys'

     Hat's off to CBS News and who-knows-who-else for this up-to-the-minute breaking news! We now know that the Maya domesticated turkeys a thousand years earlier than previously known. Staggering. Truly. But the really startling part is that these gobblers are believed to have been sacrificed as part of some ritual or other, and their inedible parts used for medicine or Hallowe'en jokes or something like that.
     Kinda makes ya wonder what sorta people they were, sacrificing those poor bird-brains for some sorta pagan ceremony! Savages! PETA should be boycotting the ancient Maya. 
     By the way, got any plans for Thanksgiving?
Gabriel Stabile photo from the
New Yorker's online only edition, November 23, 2011.

By the way, CBSNews could use a good online editor. I can't see any reason why the Ancient Maya would have wanted to sacrifice 'ancient' turkeys, whether domesticated or not. If you've ever had an old Tom turkey, you'll know what I'm talkin' 'bout. Ancient turkeys are way harder to chew--that's if they have any meat left on them at all!

Thursday 16 August 2012

What's Up With That, Dr. Science?

Updated 2012 08 16 15:00 Z: see below

The media are very much in character this week, after publication of Eriksson and Manica's 'Effect of ancient population structure on the degree of polymorphism shared between modern human populations and ancient hominins' in PNAS and that of Leakey et al., in Nature,  'New fossils from Koobi Fora in northern Kenya confirm taxonomic diversity in early Homo.'    
     It's like a Bizarro world, or the curious story of Henny-Penny [A.K.A. Chicken Little]. The Sky is Falling! And it happens every time someone presumes to erect a new hominid taxon or publishes a contradictory interpretation of an extant archaeological or other dataset. The take-home message of the current headlines is something like
Holy Shit! We Didn't Breed with the Neanderthals After All! Or did we? How are we ever gonna know?
and
Fossil Hunters Change Their Interpretation of Human Evolution More Often Than I Change My Underwear! Maybe the Crazy Creationist Christian Supremacists are right, after all--there is no irrefutable evidence of evolution.
And, as far as I'm concerned, at such times science is the unintended victim of its own success as much as it is of its own failure. But how did it get like this? 
     I'll be the first to admit that many before me have sputtered on about the media and the public's attitude toward science, especially so-called soft, or social, science [e.g. anthropology & archaeology]. The human palaeontologists manage to escape the worst of the criticisms, but they're not completely out of hot water, 'specially amongst those aforementioned Christianists.
     If I may, I'd like to turn the whole problem on its head and give it a subversive spin. A long time ago I wrote a synthetic piece on archaeological science. Brave hearts can find it here. In brief, while no one was watching [least of all the 'hard' scientists] a revolution of sorts has taken place. As Alison Wylie* puts it
...archaeologists can and do use fragmentary data to achieve an understanding of the cultural past in a way that positivist, empiricist theories of science are entirely incapable of comprehending.. 
And therein hangs a tale.  
     I don't expect many among you to be familiar with the root of Wylie's question. Suffice it to say that in the 1980s there was considerable, rancorous, disagreement between what was then the unfolding Post-Modern worldview and the practitioners of what Binford called Processual Archaeology [also known as the New Archaeology]. Before Wylie, Thomas Kuhn had been widely embraced for his historical, sociological study of what he termed Scientific Revolutions [paradigm shifts, he called them, and Binford and others saw themselves as the movers and shakers of a revolution--a paradigm shift--in archaeology]. 
     By the time I arrived at UC Berkeley in 1988 it was all-out war in the literature. I found myself confronting what was prematurely deemed to have been the end of the so-called scientific project. Fellow graduate students were all set to forego what they thought of as science in favour of a research program based on the insight that no one is able to step out of their cultural and disciplinary experience to achieve the 'objectivity' espoused by most scientists. The quite erroneous conclusion seemed to be that 'anything goes' when it comes to understanding anything more complex than a light switch.
     I shan't undertake a commentary on Post-Modernism at this juncture. I'd rather explain what I've just alluded to. As Wylie has tried to explain since the late 1980s, as others have attempted to do with varying degrees of success, the 'problem' of science isn't so much the culture or [sometimes more importantly the gender] of its practitioners, the problem is the way science, itself, is understood. It almost seems old hat to me now, but it's worth remembering that for about, oh, four hundred years science was seen as a pathway to truth and an engine of 'sure and certain' knowledge, in opposition to superstition, personal experience, and supernatural explanations of physical phenomena. But you must understand that when Wylie refers to 'empiricists' she's not talking about people like you and me, who rely on empirical observation to make knowledge. She's talking about a way of thinking about science that for a long time maintained that science was all about 'sense' data.
     Those 'sense' data are presumed to be impervious to bias, and can be perceived by anyone--unlike, for example, a trance, or an epiphany, which can only be experienced by one, or a very few, persons. Science positioned itself against the Church almost from the beginning, which as everyone knows, spelled trouble for the likes of Galileo! So, for about 400 years, until some time after the middle of the 20th century, science had been thought of as a means of examining the physical world in a way that precluded interpretation, and instead made knowledge by building upon observation that was immune to the vicissitudes of intersubjectivity, bias, and speculation. 
     Unfortunately for most people alive today who call themselves scientists (social or otherwise), the empiricist train has left the station. But they're unaware that they've been left stranded on an empiricist platform. I'll give you a straightforward example of the difference between 'empiricist' science and what Wylie refers to as a 'realist' science that can, and does, explain the successes of the last 400 years as something well beyond the collection of observations and the creation of physical 'laws' [e.g. Gauss's]. My simple example is this. [By the way, this is an example taken from the voluminous philosophical literature about science, and refers to a rather big name in the history of science. But I won't spoil it by telling you who it is.]
     Empiricist A plucks the strings of a guitar. Empiricist A hears a sound. But Empiricist A, being the good little empiricist that he is, can't bring himself to say that plucking the string 'caused' the sound, since he was unable to 'observe' whatever it was that translated the pluck into the sound. [It sounds ludicrous to me. And I'm sure it does to you. But that is precisely the way 'science' has been practiced for centuries.] Empiricist A proposes a physical 'law' to explain the relationship between the pluck and the sound. However, his law has nothing to do with what occurs when the string is plucked, and its vibrations ripple through the air such that he could hear a sound. Instead, his law, the Law of Constant Conjuction, 'explains' the sound by proposing that whenever a guitar string is plucked it is followed immediately by a sound. That is the best that an empiricist science could do in the days before fancy instruments made it possible to break down the string-to-sound sequence into smaller--observable--bits long before oscilloscopes made it possible actually to aid in the empiricist understanding of acoustic phenomena.] But long before empiricists figgered out a way to explain the guitar sounds in a way that would fit within their uber-rationalist framework you and I had 'modelled' the process after the motion of the water after a stone is tossed into the middle of a pond, when a circle of ripples [waves] races across the surface.
     What Wylie is telling us, and what most of us always knew, is that there is more to making scientific knowledge than 'sense' data. Long before bevatrons and tevatrons and Large Hadron Colliders smart thinkers had modelled the motion of electrons in an atom by analogy to planets orbiting around stars. Yet, such 'models' for the way things work are anathema to empiricists. You can't make knowledge about anything you can't see, hear, taste, touch, or smell.
     By contrast, a 'realist' view of science is that we may never see, or otherwise perceive, the motion of electrons in an atom. But the knowledge we have, based on the planetary model, is no less scientific, it's no less successful as a means of understanding physical reality, than the Law of Constant conjunction. Instead, it's actually better, because it's sensible, and realistic, and is the best way we have of interpreting the observations we can make. And if you don't believe me, try standing next to an atomic bomb when it's detonated. Models or not, I think those pesky physicists have figgered it out!
     Getting back to the reason for tonight's diatribe, the Frantic Press and the Far Right [Far Out] Christian Supremacists, and an unbelievably large number of your fellow citizens think that science has failed, or is not to be trusted when someone like yours truly interprets the archaeological record in a way that flies in the face of decades of received knowledge, or someone suggests that we can't state unequivocally that the Neanderthals and modern humans interbred, or that there's [yet] another species of hominid in East Africa that co-existed with the two others we've known about since the 1980s. That way of viewing science--as right or wrong, with no gray--is the result of very influential people who cleave to a failed view of science. And from here on out, it's not gonna be our problem. Now is it?

* Wylie, M. Alison. 1982. Positivism and the New Archaeology. PhD dissertation, History and Philosophy of the Social and Behavioral Sciences, State University of New York at Binghamton.

Update:
I'm fairly certain that I can't be as eloquent or as expansive as one needs to be when engaging in discussions of this sort. Be that as it may. A comment on the above has compelled me to try saying it a different [and far more brief] way than the above. Here goes nothing!
     The point to be understood is that "pure" [or "hard"] science was never what it proclaimed itself to be, and that archaeologists and what many call "pure" scientists make knowledge using the same kind of reasoning, by reference to the empirical realm. Moreover, the empiricist "account" of Science was never a "realistic" description of how scientific knowledge is made. A narrow, Empiricist, view of science is, in very "real" terms, incapable of accounting for some of the greatest successes of Science over the centuries [e.g. no one's yet 'seen' gravity, but we know it exists; no one's seen the past, but we know it exists AND that we can make reasonable sense of it--the past does not exist in the empirical world--an idea that was (and still is) anathema to Empiricist accounts of science].
 Hence, a 'realist' view of science, which recognizes that we don't make knowledge ONLY by Empiricist 'rules of engagement', and which says that we can create knowledge of the physical world even when we can't put our fingers on the 'sense data', or can't describe our inferences in an IF A, THEN B equation...a realist view of the creation of scientific knowledge is a far more accurate account of how science works than that of the Empiricists.
Ipso facto, forget the dichotomous (and divisive), and specious distinction between "pure" or "hard" science and what we so-called social scientists do. We're all in the same game, epistemologically speaking! And it really doesn't matter if no one else 'believes' what I'm parroting here--you can't change what is, you can only be hampered by what you think "IS" if it leads you to constrain yourself in irrational ways. That's where the New Archaeology fell over--its goals were 'realist' but its methods were 'empiricist' and it couldn't get past that untenable tug-of-war.