"The Barefoot Professor", a behind-the-scenes look at the new Nature paper.
Humans that had to escape from saber-toothed cats, giant hyenas, and charging mammoths did not wear Nike or Adidas sneakers. They ran barefoot, but don't feel too bad that they did not have good running shoes to help them. As suggested by a team of researchers led by Daniel Lieberman in the latest issue of Nature, habitually shoeless runners have a unique step that may be better for our feet than even the most expensive, cushioned running shoe. Read the rest of this post... | Read the comments on this post...... Read more »
Lieberman, D., Venkadesan, M., Werbel, W., Daoud, A., D’Andrea, S., Davis, I., Mang’Eni, R., & Pitsiladis, Y. (2010) Foot strike patterns and collision forces in habitually barefoot versus shod runners. Nature, 463(7280), 531-535. DOI: 10.1038/nature08723
Ten days ago, the Sunday Times - Britain's "newspaper of record" - recorded thatBlonde women born to be warrior princessesWomen with fair hair are more aggressive and determined to get their own way than brunettes or redheads, according to a study by the University of California... “We expected blondes to feel more entitled than other young women — this is southern California, the natural habitat of the privileged blonde,” said Aaron Sell, who led the study...Well who'da thought it. Other sources repeated the story. The problem is, it was all made up. The study in question had nothing to do with blondes, or indeed hair at all. As originally reported over at Neuroworld, Dr. Aaron Sell, the lead author, denies saying the things he is quoted as saying in the article. His response -Journalistic ethics requires, at a minimum, that you remove from this article all references to me, and to the research I and my collaborators have conducted. This article consists almost entirely of empirical claims and quotes about blonde women that Mr. Harlow fabricated, and then attributed to me. Please take the article offline immediately. Once your investigation is completed, please issue a retraction...The Times has done neither - the article's still online. According to Dr. Sell, what happened was that journalist John Harlow noticed the paper, which is about, amongst other things, physical attractiveness and anger. Harlow, whose recent output includes "Brad Pitt and Angelina Jolie no more" and that incisive piece of reportage, "Sandra Bullock overtakes Streep in dash for awards glory", wrote to Sell saying that he was writing an article about blondes, and asking whether Sell's data was relevant.Sell hadn't considered hair color in his research, but he reanalyzed his data on Harlow's request. He found no association between blondness and personality, which is not surprising because it's hair we're talking about. Harlow, apparently unhappy with this, wrote the article anyway, simply making up various claims about blondes and attributing them to Sell and his paper, backed up with some fake quotes.That's what Sell says, anyway. Maybe the Times dispute it, but since they haven't responded in any way, I guess we have to assume they agree. Science blogger Satoshi Kanazawa commented that "by American standards, all British newspapers are tabloids because they don’t distinguish between what is true and what they make up. " You can see his point. But I think the problem is especially serious when it comes to science journalism.A journalist who faked an interview with a politician would be sacked on the spot - so noone would even consider doing that. Scientists, apparently, are fair game. The standard of British journalism in general may not be fantastic, but what appears on the "Science" pages is bad even by the standards of the rest, as Neuroskeptic readers know. To be fair to other journalists, Harlow's article is even worse than average. But it's not unique - a couple of years ago the Guardian ran a front-page story about autism research which was also largely made-up.*In all the excitement over the Times, though, the paper itself hasn't attracted much discussion. What Sell et al actually found was that in men, physical strength (as measured by ability to lift weights, etc.) correlates with the tendency to get angry, and feelings of entitlement. And in both men and women, perceived physical attractiveness was also correlated with angriness and entitlement. Specifically, the men and women were University of California students.What does this mean? Sell et al describe their results as empirical proof of the "recalibrational theory" of anger. This is the idea that evolution provided us with anger to make other people treat us better, because early humans who got angry reaped benefits from it -The function of anger is to orchestrate behavior in the angry individual that creates incentives in the target of the anger to recalibrate upwards the weight he or she puts on the welfare of the angry individual.In essence: we get mad when we think that someone's not giving our interests the weight they deserve. Anger signals to the offender that if they don't pay the proper respect, we'll make them sorry, so they'd better fall into line... or else.Sell et al say that the recalibrational theory predicts that people with more power to make others sorry - people with "formidability" - should get angry more easily, because their formidability means that they're likely to triumph if things came to blows (either literally or metaphorically).They further say that in men, physical strength is an important part of formidability, while in women, attractiveness is more important. While men have the muscles, women have the babies, at least if they're fertile, so having a hot (a signal of fertility according to some accounts) woman, decide not to sleep with you is the ultimate evolutionary defeat for any male who wants to propagate his DNA, which, according to evolutionary psychology, is all of us -males will tend to preempt and hence monopolize ... Read more »
BMC Biology has recently published a paper (It’s Open Access!) which explores trends in brain size in the Primates. A trend toward a larger brain is usually considered one of the “hallmarks” of the Primates, but Stephen Montgomery and his colleagues have shown that in many lineages, there is a trend towards secondarily “shrunken” brains.
The [...]... Read more »
Montgomery, S., Capellini, I., Barton, R., & Mundy, N. (2010) Reconstructing the ups and downs of primate brain evolution: implications for adaptive hypotheses and Homo floresiensis. BMC Biology, 8(1), 9. DOI: 10.1186/1741-7007-8-9
The paper I discussed earlier about evidence that corn was imported to Chaco was interesting, but while it provided important information about the poorly understood “Mesa Verdean” period after the fall of the Chaco system it didn’t address the question of food imports during the operation of that system. This has been a topic of [...]... Read more »
BENSON, L., STEIN, J., & TAYLOR, H. (2009) Possible sources of archaeological maize found in Chaco Canyon and Aztec Ruin, New Mexico. Journal of Archaeological Science, 36(2), 387-407. DOI: 10.1016/j.jas.2008.09.023
A new study in PLoS Biology suggests one of the most common Western European Y halplogroups, R1b1b2, might have originated in Turkey and radiated into Europe with the spread of agriculture during the Neolithic. This is significant because this haplogroup is the most frequent in Western Europe, and has been posited as a signal from [...]... Read more »
Balaresque P, Bowden GR, Adams SM, Leung HY, King TE, Rosser ZH, Goodwin J, Moisan JP, Richard C, Millward A.... (2010) A predominantly neolithic origin for European paternal lineages. PLoS biology, 8(1). PMID: 20087410
Cinnioğlu C, King R, Kivisild T, Kalfoğlu E, Atasoy S, Cavalleri GL, Lillie AS, Roseman CC, Lin AA, Prince K.... (2004) Excavating Y-chromosome haplotype strata in Anatolia. Human genetics, 114(2), 127-48. PMID: 14586639
Somewhere between 700 and 900 AD, the Maya civilisation in Central America seemed to collapse. Why? For some time, the conventional explanation has been deforestation. They were so efficient at chopping down trees for timber and for farmland that they got rid of the forest, and without it, the fertile soil was eroded. It’s not [...]... Read more »
McNeil, C., Burney, D., & Burney, L. (2009) Evidence disputing deforestation as the cause for the collapse of the ancient Maya polity of Copan, Honduras. Proceedings of the National Academy of Sciences, 107(3), 1017-1022. DOI: 10.1073/pnas.0904760107
Ford, A., & Nigh, R. (2009) Origins of the Maya Forest Garden: Maya Resource Management. Journal of Ethnobiology, 29(2), 213-236. DOI: 10.2993/0278-0771-29.2.213
Since it seems to be Linguistics Week here at Gambler’s House, here’s another post on Jane Hill’s theory that the spread of agriculture into the Southwest was associated with a migration of speakers of Proto-Northern-Uto-Aztecan (PNUA) from somewhere in Mexico. Previously I discussed an article of hers from 2001 in which she tried to show [...]... Read more »
Hill, J. (2008) Northern Uto‐Aztecan and Kiowa‐Tanoan: Evidence of Contact between the Proto‐Languages?. International Journal of American Linguistics, 74(2), 155-188. DOI: 10.1086/587703
Well, what do you know... it looks as though Neanderthals in Mediterranean Spain were up to all sorts of interesting stuff ca. 55-50kya! Hot on the heels of the news that ornaments and coloring materials were found in Mousterian deposits at Cueva Anton and Cueva de los Aviones, we get news that Neanderthals at Abric Romaní (Spain, near Barcelona) appear to have had well defined sleeping areas that bear striking resemblance to those found in rockshelters used by extant hunter-gatherers (Vallverdú et al. 2010). But wait, there's more! The evidence reported by Vallverdú et al. (2010) also includes the impression of a ca. 5m-long worked wooden post (see image below) likely used as part of some kind of ephemeral wooden structure like a lean-to or a hut/tent pole. And as if that wasn't enough, an analysis of the hearths and occupied area suggests that level N (dated to ca. 55kya by U series) formed as the result of repeated occupations by small groups of 8-10 hominids who used the for brief periods of time, one of the first empirically derived for Neanderthal group size.From Vallverdú et al. (2010:141) - color image available from the online edition of Current Anthropology.There's a lot to digest in that preliminary report. First, the sleeping areas. This is important since it relates to the structured use of space, which is often argued to be something that differentiates modern humans from Neanderthals. Of course, the recent paper on Lower Paleolithic spatial organization at Gesher Benot Ya'aqov in Israel has done a lot to dispel that preconception lately, but it's still framing how many researchers conceptualize Neanderthals. The Romaní investigators identified 19 hearths in Level N (you can see them as the dark patches in the picture above), and identified that they were arranged in three distinct areas within the rockshelter: inner (closest to the backwall), frontal (around the largest travertine accumulations), and frontal (in the center of the shelter). An analysis of the hearths indicates that they were used repeatedly in a smouldering manner for brief periods of time. As well, the distance between the hearth and the distance between the hearths and the backwall in the inner zone all combine to "suggest that this space represents a sleeping-and-resting area in the Romaní record (Vallverdú et al. 2010:142). As the authors emphasize, there is a small but growing number of studies that have documented similar types of spatial organization at other Middle Paleolithic sites, including notably Tor Faraj, Jordan (Henry et al. 2004). These all suggest that Neanderthals were able to segregate their activities as well as to use the thermal characteristics of shallow hearths and rockshelter morphology to create comfortable sleeping areas, including at sites like Abric Romaní that faces N/NE and would not have mostly shaded and humid without such effective accommodations.The wooden pole that the authors describe was identified on the basis of its impression in travertine deposits (see part b of the picture above which also shows what appears to be the pattern created by bark on the impression). "The travertine wood imprint measures 510cm in length and 6cm in width at one end and 3cm at the other. It has a rectilinear form, an absence of branches, and it ir fragmented, indicating probably that this piece of wood was subject to human modifications" (Vallverdú et al. 2010:140). Its position at the edge of the inner zone which is where evidence for a sleeping area was identified suggest to the authors that it was part of some sort of larger structure, maybe "a simple triangular structure leaning against the wall' (Vallverdú et al. 2010:143). Here, I'll simply point out that there is evidence for wooden structures at other Middle Paleolithic (and by extension Neanderthal) sites in Europe, including notably at the site of La Folie, France (which I discussed at length in another post), and which dates to ca. 57.2kya, roughly the same age as Level N at Abric Romaní.The aspect of the paper which I thought was especially thought-provoking concerns the estimation of Neanderthal group size. Based on the size of the inner zone, the authors "assume that a density of individuals using 1.5-2m2 each or a group of 8-10 hominids could occupy this area. Hearth spacing in sleeping areas [based on ethnographic examples - JRS] suggests an occupation number of 4-6 individuals." (Vallverdú et al. 2010:143). While this estimate is extremely interesting in light of what it may tell us about Neanderthal social organization, before people go out and use this paper to show that Neanderthals lived in extremely small groups, it is important to emphasize that this group size is characteristic of fleeting occupations of the site. If anything, this may be telling us something about the size of task group (or some similar social unit) more than anything about overall group size in Neanderthals. If Level N at Romaní reflects a satellite site to a larger 'home base' type settlement, then we may start extrapolating from that 8-10 person figure some more grounded estimates of the extent of Neanderthal social units broadly speaking. Fascinating. ReferencesHenry, D. O., H. J. Hietala, A. M. Rosen, Y. E. Demidenko, V. I. Usik and T. L. Armagan. 2004. Human Behavioral Organization in the Middle Paleolithic: Were Neanderthals Different? American Anthropologist 106:17-31.Vallverdú, J., Vaquero, M., Cáceres, I., Allué, E., Rosell, J., Saladié, P., Chacón, G., Ollé, A., Canals, A., Sala, R., Courty, M., & Carbonell, E. (2010). Sleeping Activity Area within the Site Structure of Archaic Human Groups Current Anthropology, 51 (1), 137-145 DOI: 10.1086/649499... Read more »
Vallverdú, J., Vaquero, M., Cáceres, I., Allué, E., Rosell, J., Saladié, P., Chacón, G., Ollé, A., Canals, A., Sala, R.... (2010) Sleeping Activity Area within the Site Structure of Archaic Human Groups. Current Anthropology, 51(1), 137-145. DOI: 10.1086/649499
For a brief change of topic, let's take a look at language evolution! I wrote up the following novel review paper blog post for a non-biological evolution seminar course I'm involved with. We're essentially first examining various key topics in evolutionary biology (alas too briefly!), exploring how the by-now well-established field of evolutionary linguistics successfully applies evolutionary theory to languages (technically much of it before biology came along...linguists invented phylogeny!), and then playing around in the vast and violent Wild West that is cultural evolution, hopefully sufficiently equipped by then to discriminate shit from gold and ward off the marauding bands of pseudoscientists.For the record, I have a very limited linguistics training - only a handful of undergrad courses as my electives, so please point out and criticise any inaccuracies (and be generally skeptical, although I'd imagine most of my readers are by now =P) Any errors in attempts at explaining the linguistics behind the following paper are mine, and mine alone. Slightly edited to suit broader audience. Enjoy!Have you ever wondered why English seems so simple compared to some other languages, particularly those notious for complex grammar like Russian or German? Have you wondered whether there was any reason why the local [Pacific Northwest] languages are so complex and filled with intricate grammar? May I interest you in a very recent awesome paper from PLoS ONE: Language Structure Is Partly Determined by Social Structure Lupyan & Dale 2010 (open access) They examined 2236(!) languages and looked for correlation between their morphological complexity and the 'linguistic niche' -- whether the language is spoken over a vast area mostly by strangers, or used within a small tightly-knit community. The majority of the world's languages are 'esoteric' (smaller population, fewer neighbouring languages, smaller area; eg. Tatar, Piraha, Ju|'hoan, Nuu-chah-nulth), contrary to what is most obvious to us, ie the 'exoteric' languages like English or Swahili. One would expect that the use of an exoteric language as a lingua franca may result in some changes in its structure, as its 'purpose' or 'function', if you will, is quite different. Anyway, they found that: 1. Exoteric languages tend to be isolating; that is syntactic stuff (tense, person, etc) is marked by independent morphemes rather than affixes or other inflections. For example, in Russian (which is still very exoteric, but less than English or Mandarin) house would be /dom/, but to say "of [the] house" (that is, house[gentitive]) you say /doma/, using a suffix instead of a preposition to indicate the case. In this case, English would be more of an isolating language, whereas Russian is more of a fusional one. By the way, we Russians do use a mixture of both suffixes and prepositions -- would be interesting to see if the use of prepositions intensified over time as Russian became more dominant in its region. 2. Exoteric languages tend to have fewer case markings (see Russian example above); furthermore, Exoteric languages seem to use the Nominative/Accusative system (English, Russian, German, etc) rather than the Ergative/Absolutive system (eg. Basque), which still completely eludes me. Probably because it's rare and unusual. As far as I can 'understand', ergative languages basically use the object as the subject of the verb. Ie, 'dog walked' would actually mean 'walked' acted on the dog, ie the 'dog was walked'. Now 'dog walked boy' would mean 'the dog was walked by the boy', so the primary argument of the verb is the object, not the subject. Or something like that. When I was randomly reading up on some German back in the day, it was interesting to find their case system to be completely in ruins -- it was obviously about to become the grammatical analogue of a pseudogene! Many of their suffixes either repeat in different instances, or don't even exist anymore. It's a mess to learn, and it seems like modern German relies on their case system less and less. Furthermore, Old English had cases. Yes, this language once had a hard-core, well-structured and absolutely essential case system, just a few centuries ago! I wouldn't be surprised if German cases go the way of the English ones in a few hundred years... for the record, Proto-indoeuropean had something like 8 or 9 of them. 3. Exoteric languages have fewer grammatical categories marked in the verb -- some of you may remember from learning French (or Spanish, or German) the billions of different conjugation schemes you had to memorise for the verbs -- damn things had to agree in number, gender, various intricate tenses, aspects etc. English seems to be much simpler morphologically. And it is. This is how we inflect 'walk' in English: (remember I'm talking strictly about morphology -- the syntax is still quite complex and intricate) I, we, you, they - walk; he, she, it - walks past - walked progressive - walking Now to compare with Russian: infinitive -- /gulyat'/ (to go for a walk) (picking regular verbs) [1st person singular] /gulyayu/ [2nd p sg] /gulyayesh/ [3rd p sg] /gulyayet/ [1st p plural] /gulyayem/ [2nd p pl] /gulyayete/ [3rd p pl] /gulyayut/ past: [masculine signular] /gulyal/ [fem sg] /gulyala/ [neuter sg] /gulyalo/ [plural] /gulyali/ adverbial participle: /gulyaya/ imperative: [2sg] /gulyay/ [2pl] /gulyayte/ And probably a few more I missed. Now, Russian is a piece of cake compared to perhaps MOST of the world's languages! 4. Exoteric languages tend not to mark noun-verb agreement. As we've seen above, English is strikingly simple in that department -- there's only number agreement! Now, if French or Russian are intimidating, try thinking about inflecting the verb based on the subject AND the object AND how the verb is done by the subject onto the object... apparently, many languages do that. We had to look at Nuu-chah-nulth (aka "Nootka") in an introductory grammar&syntax course and oh my do they inflect for EVERYTHING. You have one word sentences that go on for a few rows of syllables...fascinating! 5. Exoteric languages seldom mark evidentiality by affixation -- that is, how a certain thing is known about is instead marked by verb choice and random modifiers. You may have noticed that academic writing requires a lot of cumbersome qualifiers and disclaimers embedded in every sentence, apparently. It tends to be that this may well be an inherent feature in research writing, or so I've heard. Some languages not only allow you to identify the nature of evidence for a statement, but actively require it much like English always requires tense (which, btw, not every language does; after all, 'today', 'in the past' and 'tomorrow' work perfectly fine instead!). It seems that this feature tends to mostly happen in the 'obscure' esoteric languages. Wikipedia has some nice examples from Pomo in the intro. 6. Exoteric languages are more likely to: a) encode negation lexically (eg. by EN 'no', FR 'ne...pas', RU 'nye', etc) rather than inflectionally (eg. JP -nai) b) have obligatory plural markers (as in EN 'one cat - two cats', RU 'odin kot - dva kota'; in contrast, Japanese and Mandarin don't bother with obligatory plural markings, although in JP you could add -tachi ('many') if you really want (disclaimer: not a JP speaker...) This is why English with the stereotypical Chinese accent lacks plural marking: "Very cheap -- two dollar!" It is very curious that this is one of the very few increases in morphological complexity in exoteric languages... Read more »
Lupyan, G., & Dale, R. (2010) Language Structure Is Partly Determined by Social Structure. PLoS ONE, 5(1). DOI: 10.1371/journal.pone.0008559
The prehistoric peoples of the American Southwest were agriculturalists. Different societies may have calibrated their mix of farming, hunting, and gathering differently, but they all seem to have done all three eventually, and for most it’s quite apparent in the archaeological record that farming was the predominant method of subsistence. The crops they grew were [...]... Read more »
Hill, J. (2001) Proto-Uto-Aztecan: A Community of Cultivators in Central Mexico?. American Anthropologist, 103(4), 913-934. DOI: 10.1525/aa.2001.103.4.913
Although it can be rather difficult to define what it means to be Navajo, it is quite clear from a variety of lines of evidence that speakers of Athapaskan languages, including Navajo and the various Apache languages, have not been in the Southwest for very long compared to most of the other language groups there, [...]... Read more »
Sapir, E. (1936) Internal Linguistic Evidence Suggestive of the Northern Origin of the Navaho. American Anthropologist, 38(2), 224-235. DOI: 10.1525/aa.1936.38.2.02a00040
The last three issues of the 2009 volume of L'Anthropologie are dedicated to prehistoric art, and one the papers contained in that special volume concerns five vault fragments from Fumane Cave (Veneto region, Italy) that were recovered during excavation and that bear designs made in red ochre. The art itself is already well known and has been published in great detail as part of a monograph a few years ago (Broglio and Dalmieri 2005), but this study presents some new data on the likely age of the fragments, as well as on the composition of the pigments from which they're made.View of the inside of Fumane Cave.http://www.grottadifumane.it/FOTOGALLERY-DELLA-GROTTA.htmlThe issue with these fragment has been to precisely determine how old they are, since they are in secondary position, that is to say, they were not found where they were painted. It seems that during a cold snap following the moment on which the designs were painted on the cave, the vault surface spalled off and the fragments fell on deposits that were, logically, more recent than the paintings themselves. The oldest fragment (Fragment I in the figure below) bears a representation of some kind of quadruped was recovered in Unit A2, which is the base of the Aurignacian deposits at the site, whereas Fragment II ("the shaman", so called because the anthropomorphic figure it bears also shows some horn-like features) was recovered from the a pile mound of stones located at the cave's mouth, while the other decorated blocks were recovered in later (i.e., more recent) Aurignacian and Gravettian layers. In Italy, the Gravettian is securely attributed to modern humans, who are also widely thought to be the makers of the Aurignacian, and its earliest expression, the Protoaurignacian.The five decorated vault fragments from Grotta di Fumane.From: Broglio et al. (2009:756, Plate 2).The main issue, chronologically speaking, has been to determine when the figures were painted on the cave vault, since the layers in which they were recovered only provide a terminus ante quem for their age, in other words, an upper limit for their age. So, at first glance, there is no evidence for the age of these paintings beyond that of the layers in which they were recovered. However, in this study, Broglio et al. (2009) make the case that all the paintings date to the earliest Aurignacian at the site, that is to level A2. Historically, the dating of the earliest Aurignacian at Fumane has been hotly debated, but the authors present new dates for previously dated charcoal samples that have undergone, for the new dates, a new, more thorough pretreatment (i.e., ABOx SC). This has provided two statistically equivalent age determinations of 35,640 +/- 220 and 35,180 +/- 220 BP for level A2. Interestingly, and fittingly in light of my recent post on the presentation of calibrated and uncalibrated radiocarbon dates, they conclude that, by reference to the calibration curve based on the Cariaco Basin data and the GISP2 Greenland ice core, that "the chronological data show that Protoaurignacian Unit A2 dates to between 43,250 to 40,500 BPGISP2, with an age of 41,000BPGISP2 being statistically more likely" (Broglio et al. 2009:760; my translation, emphasis added).What allows them to tie the paintings to that age determination is the study of ochre found in Unit A2. The base and top of that layer include conspicuous concentrations of red ochre, and some ochre crayons were also recovered from A2. The clincher is that these crayons are made of the same ochre as that which was used for the parietal art. This is demonstrated by a brief compositional analysis of the pigments using various methods, that also indicates that these ochres are circum-local in provenience, being found in the Lessini Mountains, at the southern edge of which Fumane sits.In sum, while the decorated pieces themselves were not dated directly, this study provides some strong circumstancial evidence for their being of early Aurignacian age. If this attribution is correct, it provides us with some solid data about some of the iconographic canons and artistic techniques used by early Aurignacian foragers in northern Italy and some insights into the variability in artistic behavior within this cultural tradition at the beginning of the Upper Paleolithic.ReferencesBroglio, A., and G. Dalmieri (eds.). 2005. Pitture paleolitiche nelle Prealpi venete: Grotta di Fumane e Riparo Dalmieri. Memorie del Museo Civico di Storia Naturale di Verona, 2 serie. Sezione Scienze dell'Uomo. Verona, Italy.Broglio, A., De Stefani, M., Gurioli, F., Pallecchi, P., Giachi, G., Higham, T., & Brock, F. (2009). L’art aurignacien dans la décoration de la Grotte de Fumane L'Anthropologie, 113 (5), 753-761 DOI: 10.1016/j.anthro.2009.09.016... Read more »
Broglio, A., De Stefani, M., Gurioli, F., Pallecchi, P., Giachi, G., Higham, T., & Brock, F. (2009) L’art aurignacien dans la décoration de la Grotte de Fumane. L'Anthropologie, 113(5), 753-761. DOI: 10.1016/j.anthro.2009.09.016
There are a lot of oddities about the burials found at Chaco. For one thing, there are remarkably few of them. This seemed particularly strange to archaeologists in the early twentieth century who thought that the great houses all held large resident populations and that the canyon population must have been very high, and they [...]... Read more »
Kohler, T., & Turner, K. (2006) Raiding for Women in the Pre‐Hispanic Northern Pueblo Southwest? A Pilot Examination. Current Anthropology, 47(6), 1035-1045. DOI: 10.1086/508697
One of the most interesting and potentially productive lines of research in Southwestern archaeology these days involves the use of chemical analyses of various archaeological materials to extract more information about the societies that used them than is apparent just from looking at them. The oldest and most established type of research like this is [...]... Read more »
Benson, L. (2010) Who provided maize to Chaco Canyon after the mid-12th-century drought?. Journal of Archaeological Science, 37(3), 621-629. DOI: 10.1016/j.jas.2009.10.027
Nicole Waguespack and a bunch of others (including four of the Mythbusters gang, which leads one to wonder whether this will be the basis of a future episode) ask the question: "Given that so many hunter-gatherers use/d stone-tipped projectile, what are the advantages of a stone tip relative to one whose point is simply sharpened wood?" This is a good question to ask, since crafting an projectile point from stone consumes more time, effort and resources than simply sharpening the end of the shaft that you'll be making anyway. Hell, one could even argue that knapping a stone point incurs some additional risk since you risk slicing up your hand as you do so, as anyone who's ever tried their hand (eh!) at flintknapping knows all too well. These costs are all the more important to keep in mind given the frequency at which stone points break during use (Waguespack et al. 2009:787).As the authors argue, it's generally assumed that stone makes for a more effective projectile point, though this has rarely, if ever, been tested empirically. As they state:"Numerous ‘common knowledge’ explanations appear to be generally accepted regarding the superiority of stone, and to a lesser extent, osseous point tips relative to sharpened staves (e.g. Guthrie 1983; Arndt & Newcomer 1986). Assumptions concerning performance (e.g. durability of the tip), lethality (e.g. length of cutting edge, depth of penetration) and aerodynamics (e.g. weight distribution, flight paths) abound. Unfortunately, few of these assumptions have been verified experimentally (Waguespack et al. 2009:787)." To test whether stone is actually more efficient, Waguespack et al. (2009) (available as a free pdf here)made replicas of six wooden and six stone-tipped arrows and shot them at a human torso-shaped block of ballistic gel, draping it with caribou hide in some cases to simulate the arrow having to pierce the thick skin of some animals. They conducted two tests. The first, designed to see whether stone and wood tips penetrate a target more or less deeply, had the arrows shot from a compound bow 1.1m away from the target. The second, designed to see if the two types of arrowheads have different degrees of accuracy, had the arrows shot from the same contraption but at a distance of ca. 16.75m.Picture of the experimental set-up used by Waguespack et al. 2009.(from Waguespack et al. 2009: Figure3, p. 794.)The results of these experiments indicate that both arrow types bestow equal degrees of precision to their users and, most importantly, that stone-tipped arrows provide only marginally higher degrees of target penetration (about 10% more), especially considering that both arrow types penetrated more than 20cm into the target. These observations lead the authors to conclude that the benefits of using stone-tipped arrows probably do not make up for the extra time, resources and risk involved in making them. Therefore, they argue, it is likely that the ubiquity of stone tips is driven by some other consideration, either other parameter of hunting effectiveness or social dimensions of projectile point making, such as the prestige derived from skillful stone working.While there is some ethnographic evidence for the functional argument (e.g., Ellis 1997), Waguespack et al. (2009) provide a good discussion of why stone points are effective conveyors of social identities and/or a form of costly signaling. Costly signaling basically refers to behaviors that are not strictly functional but nonetheless serve to augment the social standing of the people able to effectively engage in them, be it through more finely honed skills or access to resources unavailable to others (or their profligate use).Currently having lithics on the brain since I'm preparing to teach my Lithic Analysis seminar this coming terms (there's still some open seats if you're an interested student living in Colorado!), I thought this was a really good study that yields both interesting results and a powerful demonstration of how experimental archaeology can help answer long-standing anthropological questions (and, in this case, in a manner appealing to a wide audience!). With that in mind, I was nonetheless left wondering whether results might have differed if other types of projectiles had been used (e.g., darts propelled using a spear thrower, or hand-cast spears or javelins). Likewise, I would have been really interested in seeing the penetration results of both point types in the accuracy experiment, since 16.75m (ca. 50 feet) is likely to have been a more appropriate prey-hunter distance approximation than 1.1m (ca. 4 feet) used in the penetration experiment.In any case, if the authors are right, this opens up some really interesting avenues to research technologically-mediated costly signaling in the deep past. Since stone points were used as far back as the Middle Paleolithic and Middle Stone Age (ca. 300,000 years BP), it implies this practice may be quite old. In sum, this paper provides a good theoretical and empirical basis to ground studies of costly signaling as reflected in some classes of chipped stone implements (i.e., points) which are certainly better in that respect than handaxes, as I've discussed recently.ReferencesEllis, C.J. 1997. Factors influencing the use of stone projectile tips: an ethnographic perspective, in Projectile technology (H. Knecht, ed.), pp. 37-74. New York, Plenum Press.Waguespack, N.M., Surovell, T.A., Denoyer, A., Dallow, A., Savage, A., Hyneman, J., & Tapster, D. (2009). Making a point: wood- versus stone-tipped projectiles Antiquity, 83: 786-800... Read more »
Waguespack, N.M., Surovell, T.A., Denoyer, A., Dallow, A., Savage, A., Hyneman, J., & Tapster, D. (2009) Making a point: wood- versus stone-tipped projectiles. Antiquity, 786-800. info:/
As a grad student in anthropological genetics, one of the more tedious tasks I had was aligning mtDNA sequences manually, noting the mutations (differences from the revised Cambridge Reference Sequence, which belongs to haplogroup H), and determining the haplogroup (or lineage). The difficulty was compounded by a lack of comprehensive definitions. I had a stack [...]... Read more »
van Oven, M., & Kayser, M. (2009) Updated comprehensive phylogenetic tree of global human mitochondrial DNA variation. Human Mutation, 30(2). DOI: 10.1002/humu.20921
There’s been a lot of buzz about the new paper by Zilhão et al. (2010) on the use of pierced shells and pigments by Neanderthals at the sites of Cueva de los Aviones and Cueva Antón, in southern Spain some 50,000 years ago, so I thought I’d give a few comments about it here.This is a very significant study in that it strengthens the conclusions of previous research that suggests that Neanderthals habitually used pigments (e.g., Soressi and d’Errico 2007, which I discussed here). Importantly, it also broadens the range of color of these pigments to include, beyond black, yellows, reds, and orange. This matters because of the contention by some (e.g., Watts 2002) that the red color of ochre has important symbolic connotations that black pigments couldn’t have (e.g., blood, life, menstruation, etc.), and that this is an important distinction between Neanderthal and ‘fully modern’ use of coloring. Credibly establishing the presence of a range of colorful pigments derived from external sources at both these sites (their mineral sources are at least 3-5km distant from either cave) is therefore a major contribution to our knowledge of Neanderthal behavior and some of its symbolic underpinnings. It of major interest in this paper is the description of a fragmented horse metatarsal with a pointed tip that bears traces of orange pigment at Cueva de los Aviones. The authors argue that “this naturally pointed bone may have been used as a stiletto for the preparation or application of mineral dyes or as pin or awl to perforate soft materials (e.g., hides) that were themselves colored with such dyes.” The relevance of this observation is highlighted by the manganese ‘crayons’ that were found at the Mousterian site of Pech de l’Aze, France (Soressi and d’Errico 2007), since it establishes that Neanderthals were not only using pigments in a range of color, but also that they had a range of manners of applying it to surfaces. This strongly hints at Neanderthal pigment use being a flexible behavior that varied from context to context, in contrast to their oft-repeated characterization of people who knew how to do only a limited range of things but do them quite well (which was one of the recurrent sound bites in the Human Spark documentary recently shown on PBS and which I will discuss on this blog in coming days). Of course, in this ornament-obsessed period of paleoanthropological research, much of the buzz the paper has been getting derives from the fact that pierced shells were also recovered from both sites, many of which bore pigments. Early shell ornaments and associated pigments, of course, have recently been in the news (and discussed on this blog) and the focus of much attention in helping identify behavioral modernity (e.g., d’Errico et al. 2009). The authors make a strong case for the pierced shells having been purposefully selected by humans as ornaments (even if it’s a bit hard to get a clear idea of the trends in other periods based on the graph in the supplementary info), even if some of the perforations appear natural, artfully pointing out the interpretive double-standard that is sometimes applied to evidence associated with Neanderthals as opposed to that associated with modern humans. The discussion of Cueva Antón’s Pecten maximus upper shell valve as most likely representing an ornament is also very good. By describing that it was the external surface of this comparatively flat valve that was colored, and by stressing that Antón is currently 60km distant from the shore, the authors make a strong case for this interpretation. Even the most ardent critic is going to have to explain why and how this large and comparatively fragile colored marine shell reached this site, and the patterning of its coloration. From a parsimony standpoint, viewing it as an ornament is imminently reasonable.Overall, I think the authors are fully justified in concluding "that these innovations were fulfilling a need—aiding in thepersonalor social identification of people—that did not exist in the preceding two million years of human evolution. Our findings therefore support models of the emergence of behavioral modernity as caused by technological progress, demographic increase, and social complexification and show that there is no biunivocal correlation between “modern” anatomy and “modern” behavior" (Zilhão et al. 2010:5).They also argue that the null hypothesis about the authorship of ornaments found with ‘transitional industries’ can now reasonably argued to be Neanderthals. The argument about population pressures driving social innovation is a convincing one in this context, since the northern Mediterranean shore appears to have served repeatedly as a Neanderthal refugium during their evolutionary history and the range of food resources available in these more mesic regions likely could have sustained larger populations than elsewhere across their range.As is usual in studies of early ornaments, however, the sample size remains low, and we must remain careful about inferring too much from them. At present, what these new discovery establish is that Neanderthals used pigments in different parts of their range and applied them in different ways. As well, it establishes that Neanderthals in southern Spain used pierced shells as ornaments at least for a moment of their evolutionary history. This raises the thorny question of why such evidence has not been found in other Neanderthal sites. Is it because archaeologists were not looking for it? Or is it because this was a short-lived phenomenon that emerged in response to localized demographic conditions? And given that there are no transitional industries documented in Spain, is it warranted to link the ornaments from Los Aviones and Antón to those found in France, Italy and East-Central Europe during the transition interval? Whatever the case may be, it now is clear that archaeologists need to pay extra attention when dealing with Mousterian sites yielding shells, as we have convincing evidence that Neanderthals did, in some cases, use shell ornaments well before the transition. Referencesd'Errico, F., M. Vanhaeren, N. Barton, A. Bouzouggar, H. Mienis, D. Richter, J.-J. Hublin, S. P. McPherron, and P. Lozouet. 2009. Additional evidence on the use of personal ornaments in the Middle Paleolithic of North Africa. PNAS 106:16051-16056.Soressi, M., and F. d’Errico. 2007. Pigments, gravures, parures: Les comportements symboliques controversées des Néandertaliens. In Les Néandertaliens. Biologie et cultures (B. Vandermeersch and B. Maureille, eds.), pp. 297-309. Editions du CTHS, Paris.Watts, I. 2002. Ochre in the Middle Stone Age of Southern Africa: Ritualised Display or Hide Preservative? South African Archaeological Bulletin 57:1-14.Zilhao, J., Angelucci, D., Badal-Garcia, E., d'Errico, F., Daniel, F., Dayet, L., Douka, K., Higham, T., Martinez-Sanchez, M., Montes-Bernardez, R., Murcia-Mascaros, S., Perez-Sirvent, C., Roldan-Garcia, C., Vanhaeren, M., Villaverde, V., Wood, R., & Zapata, J. (2010). Symbolic use of marine shells and mineral pigments by Iberian Neandertals Proceedings of the National Academy of Sciences DOI: 10.1073/pnas.0914088107... Read more »
Zilhao, J., Angelucci, D., Badal-Garcia, E., d'Errico, F., Daniel, F., Dayet, L., Douka, K., Higham, T., Martinez-Sanchez, M., Montes-Bernardez, R.... (2010) Symbolic use of marine shells and mineral pigments by Iberian Neandertals. Proceedings of the National Academy of Sciences. DOI: 10.1073/pnas.0914088107
We had lots of clues that this was the case before Ardi, but now that we’ve got Ardi- the palmigrade extraordinaire, we know that humans did not go through a knuckle-walking phase, and that chimpanzee knuckle-walking has evolved since the split with our last common ancestor with them. Which would also means that it [...]... Read more »
Lovejoy, C., Simpson, S., White, T., Asfaw, B., & Suwa, G. (2009) Careful Climbing in the Miocene: The Forelimbs of Ardipithecus ramidus and Humans Are Primitive. Science, 326(5949), 70-70. DOI: 10.1126/science.1175827
Svante Pääbo’s group at the Max Plank Institute have a paper coming out in the February issue of Cell Biology. In it, they describe sequencing a complete early human mitochondrial genome from the Markina Gora specimen from the Kostenki 14 site in Russia. The remains date to around 30,000 years ago, not the oldest human [...]... Read more »
Krause J, Briggs AW, Kircher M, Maricic T, Zwyns N, Derevianko A, & Pääbo S. (2009) A Complete mtDNA Genome of an Early Modern Human from Kostenki, Russia. Current biology : CB. PMID: 20045327
UPDATE - READ COMMENTS - LEAD AUTHOR HAS GOTTEN PRESS RELEASE CHANGED
A new paper just showed up on PLoS One and it has some serious potential to be important The paper (PLoS ONE: The Effects of Circumcision on the Penis Microbiome) reports on analyses that show differences in the microbiota (which they call the microbiome - basically what bacterial species were present) in men before and after circumcision. And they found some significant differences. It is a nice study of a relatively poorly examined subject - the bacteria found on the penis w/ and w/o circumcision. This is a particularly important topic in light of other studies that have shown that circumcision may provide some protection against HIV infection.
In summary here is what they did - take samples from men before and after circumcision. Isolate DNA. Run PCR amplification reactions to amplify variable regions of rRNA genes from these samples. Then conduct 454 sequencing of these amplified products. And then analyze the sequences to look at the types and #s of different kinds of bacteria.
What they found is basically summarized in their last paragraph
"This study is the first molecular assessment of the bacterial diversity in the male genital mucosa. The observed decrease in anaerobic bacteria after circumcision may be related to the elimination of anoxic microenvironments under the foreskin. Detection of these anaerobic genera in other human infectious and inflammatory pathologies suggests that they may mediate genital mucosal inflammation or co-infections in the uncircumcised state. Hence, the decrease in these anaerobic bacteria after circumcision may complement the loss of the foreskin inner mucosa to reduce the number of activated Langerhans cells near the genital mucosal surface and possibly the risk of HIV acquisition in circumcised men."
And this all sounds interesting and the work seems solid. I note that some friends / colleagues of mine were involved in this including Jacques Ravel who used to be at TIGR and now is at U MD and Paul Kiem who is associated with TGen in Arizona. For anyone interested in HIV, the human microbiome, circumcision, etc, it is probably worth looking at.
However, the press release I just saw from TGen really ticked me off. The title alone did me in "Study suggests why circumcised men are less likely to become infected with HIV". Sure the study did suggest a possible explanation for why circumcised men are less likely to get HIV infections - the paper was justifiably VERY cautious about this inference. They basically state that there are some correlations worth following up.
The press release goes on to say "The study ... could lead to new non-surgical HIV preventative strategies for the estimated 70 percent of men worldwide (more than 2 billion) who, because of religious or cultural beliefs, or logistic or financial barriers, are not likely to become circumcised." Well sure, I guess you could say that. I think they are iplying you could change the microbiome somehow and therefore protect from HIV but that implies (1) that there really is a causal relationship between the microbial differences in HIV protection and (2) that one could change the microbiome easily, which is a big big stretch given how little we know right now.
Anyway - the science seems fine and not over-reaching. But the press release is annoying and misleading. Shocking I know. But this one got to me.
UPDATE - SEE COMMENTS HERE AND IN FRIENDFEED. LEAD AUTHOR GOT PRESS RELEASE CHANGED.
Price, L., Liu, C., Johnson, K., Aziz, M., Lau, M., Bowers, J., Ravel, J., Keim, P., Serwadda, D., Wawer, M., & Gray, R. (2010). The Effects of Circumcision on the Penis Microbiome PLoS ONE, 5 (1) DOI: 10.1371/journal.pone.0008422
This is from the "Tree of Life Blog"
of Jonathan Eisen, an evolutionary biologist and Open Access advocate
at the University of California, Davis. For short updates, follow me on Twitter.
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Price, L., Liu, C., Johnson, K., Aziz, M., Lau, M., Bowers, J., Ravel, J., Keim, P., Serwadda, D., Wawer, M.... (2010) The Effects of Circumcision on the Penis Microbiome. PLoS ONE, 5(1). DOI: 10.1371/journal.pone.0008422
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