A new method conclusively solves an ancient linguistic riddle.... Read more »
G. Artioli, V. Nociti, & I. Angelini. (2011) Gambling with Etruscan dice: a tale of numbers and letters. Archaeometry. info:/http://onlinelibrary.wiley.com/doi/10.1111/j.1095-9270.2011.00317.x/abstract
G. Bonfante, & L. Bonfante. (2002) The Etruscan language: an introduction. New York University Press. info:other/7190 5539 3
New research on ancient Chinese burials identifies male and female slave sacrifices.... Read more »
H. Zhang, F. Liu, W. Liu, J. Du, X. Wu, X. Chen, & G. Liao. (2011) Sex identification of slave sacrifice victims from Qin State tombs in the Spring and Autumn Period of China using ancient DNA. Archaeometry. info:/10.1111/j.1475-4754.2010.00553.x
Back when I was a mere first year biology student, the first thing we were taught was this:DNA makes RNA makes Protein.This is the Central Dogma of Molecular Biology, and it describes the intricate and beautiful process by which genes influence living things. The whole thing really is remarkable.Unfortunately, some people in psychiatry seem to have forgotten this. Reading some of the literature, you would think that:DNA makes DSM DiagnosesOr if you're feeling especially adventurous and concious of the fact that diagnoses are not necessarily real entitiesDNA makes Symptoms (which add up to make DSM Diagnoses)In fact, DNA has nothing to do with symptoms either, not directly. DNA makes proteins. Proteins interact with each other, and with all kinds of hormones and other signalling molecules, to control the growth and function of cells. Cells don't get symptoms. People get symptoms - and people are very complex systems made of billions of cells.So it would be extremely weird if a particular genetic variant only ever caused one specific disease. That would mean that, whenever you have that variant, and regardless of any other variants or environmental factors, it will always mess up cell function such that it causes the same ultimate symptoms.That does happen. There are lots of single-gene disorders - or to put it another way, single-disorder genes. But they may well be the exception. Rather, as Matthew State says in a short paper just out in Biological Psychiatry, the latest research suggests that genes that are linked to one psychiatric disorder are usually linked to lots of them, sometimes ones with quite different symptoms.I previously wrote about the case of "The ADHD Gene" that's actually a gene for lots of stuff including, sometimes, ADHD. State focusses on the example of the gene CNTNAP2, variants in which have been linked to (deep breath): epilepsy, mental retardation, autism, social anxiety, schizophrenia and Tourette's. Sometimes the same variant causes multiple different disorders in different people. Sometimes one variant causes one thing and protects against another, related, thing. Hmm.As State says, one possibility is that any given mutation always causes the same symptoms, it's just that our diagnostic categories are imperfect so the same symptoms get labelled as many different things. That's certainly true but as he points out, there's a more radical possibility: the same variant might cause genuinely different symptoms.mutations at single gene or locus may carry significant risks for truly divergent neurodevelopmental outcomes, neither demonstrating specificity for a clinically observable phenomenon nor conferring any reliable overlap among disparate behavioral phenotypes.How? Well, suppose there was a variant, "pinker", that codes for a fluorescent protein that makes half of your brain cells glow bright pink. By itself, that wouldn't cause symptoms. No-one would even know.Yet imagine another variant, "pinkophobe", that made cells refuse to communicate with pink cell. That wouldn't cause any symptoms either, by itself. But in conjunction with "pinker", where it would cause serious problems: half of your cells would be effectively out of action.But suppose you carried "pinker" and yet another variant, "welovepink", that made your cells respond much more strongly to pink cells. Then, you would have the opposite problem. Half of your cells would be super-responsivie to the other half, and that would probably cause epilepsy, amongst other things. You'd get symptoms, but they would be completely different symptoms from people who had "pinker" and "pinkophobe".So what symptoms does "pinker" cause? It doesn't cause symptoms. It's just a gene. The symptoms come much later. "pinker" would be associated with all kinds of stuff, even though it has a very specific role. It just codes for one protein. Genes are pretty simple folk. The complexity comes later.This is a silly example, but maybe not so far fetched after all. Neurons don't glow pink, but they do release neurotransmitters, and they don't have color preferences, but they do have receptors that respond to transmitters.State MW (2011). The Erosion of Phenotypic Specificity in Psychiatric Genetics: Emerging Lessons from CNTNAP2. Biological psychiatry, 69 (9), 816-7 PMID: 21497679... Read more »
State MW. (2011) The Erosion of Phenotypic Specificity in Psychiatric Genetics: Emerging Lessons from CNTNAP2. Biological psychiatry, 69(9), 816-7. PMID: 21497679
Life as we know it has taken some strange courses. Of all the things an animal could do with its time, pretending to be an ant is apparently pretty popular. According to a review article in the latest Current Biology, there are probably over 2000 abhorrent species of myrmecomorphs (ant impersonators), including spiders, caterpillars, mites, beetles, and other types of arthropod biodiversity I'm not familiar with, that have come to resemble ants in some form or another.
It's interesting how and why different life forms have come to p-ant-omime. For example, in the picture above, (Maderspacher & Stensmyr 2011, Fig. 3) on the left side is the crab spider (Aphantochilus rogersi) mimicking ant species in the genus Cephalotes - which the spider comes upon unawares and then feeds upon (getting pwned on the right side of the photo). If imitation is the sincerest form of flattery, then mimicry must be the most malevolent means of creepy.
Or here's a treehopper (Cyphonia clavata, an insect and not a spider like above) that doesn't just disguise itself as an ant, but rather has a whole ant-shaped appendage bursting from its back in a disgusting perversion of alien birth in the Alien series (Maderspacher & Stensmyr 2011, Fig. 1). It is quite remarkable that a surprisingly common yearning to be perceived as an ant has resulted in convergent evolution of an ant-ish figure in myriad of nature's more disgusting creations, not to mention in ants themselves.
ReferenceFlorian Maderspacher & Marcus Stensmyr (2011). Myrmecomorphomania Current Biology, 21 (9) : R291-293. doi:10.1016/j.cub.2011.04.006... Read more »
Florian Maderspacher, & Marcus Stensmyr. (2011) Myrmecomorphomania. Current Biology, 21(9). info:/doi:10.1016/j.cub.2011.04.006
True story.... Read more »
Marzluff, J., Walls, J., Cornell, H., Withey, J., & Craig, D. (2010) Lasting recognition of threatening people by wild American crows. Animal Behaviour, 79(3), 699-707. DOI: 10.1016/j.anbehav.2009.12.022
A little over 2 million years ago there a major divergence of hominids, leading on the one hand to our earliest ancestors in the genus Homo, and on the other hand to a group of 'robust' australopithecines, the latter group a failed evolutionary experiment in being human. In our ancestors, parts of the skull associated with chewing began to get smaller and more delicate, while the robust australopithecines increased the sizes of their crushin'-teeth and chewin'-muscle attachments...... Read more »
Cerling TE, Mbua E, Kirera FM, Manthi FK, Grine FE, Leakey MG, Sponheimer M, & Uno KT. (2011) Diet of Paranthropus boisei in the early Pleistocene of East Africa. Proceedings of the National Academy of Sciences of the United States of America. PMID: 21536914
McCollum, M. (1999) The Robust Australopithecine Face: A Morphogenetic Perspective. Science, 284(5412), 301-305. DOI: 10.1126/science.284.5412.301
Ungar PS, Grine FE, & Teaford MF. (2008) Dental microwear and diet of the Plio-Pleistocene hominin Paranthropus boisei. PloS one, 3(4). PMID: 18446200
A comparison between modern UFO abductions and supernatural abductions in folklore... Read more »
The hymen: you know it as the tissue that gets removed when you lose your virginity, but is there more you might be missing?... Read more »
Hobday, A.J., Haury, L., . (1997) Function of the human hymen. Medical Hypotheses, 171-173. info:/
Last year, the world of psychiatric genetics was rocked by the news that a highly-studied gene, believed to be associated with depression, wasn't in fact linked to depression at all.The genetic variant was 5-HTTLPR. It's a length variant in the gene coding for the serotonin transporter protein (5HTT) which the target of antidepressants like Prozac. There are two flavors of this variant, short and long.Many studies have shown that the short ("s") variant is associated with a high risk of getting depression in response to stress - but then last year a large meta-analysis of all the evidence concluded that there was in reality no link. Bummer.Now another team of researchers have done a new analysis of the 5-HTTLPR & stress & depression data and they claim that there is a link after all: hooray! So who's right? I'm not sure, but the new paper raises many questions.The new paper puts together the results of all 54 studies which have looked at this gene in the context of depression, caused by any kind of stress. The authors were intentionally liberal in their inclusion criteria: studies in any population were OK, for example they included people with Parkinson's disease or heart disease.They say that this is the main difference between the present work and earlier meta-analyses that found no link. The famous 2010 paper, for example, only included 14 studies because they only considered certain kinds of stress.Anyway, the short variant is associated with depression after all, across all of the studies. They extracted the p values from the results of all previous studies, and took the average of those, weighted by the sample size. They found a very significant association: P=.00002.Here's all the results. Each square is a study, the further to the left, the more strongly they found an association. Bigger squares mean larger studies. As you can see, most studies found a link but the three largest studies - which were much larger than the others - found none. Hmm.In terms of specific kinds of stress, they found strong evidence that "specific stressors" (like medical illness), and childhood trauma, were associated with more depression in s-allele carriers. However, in the studies on "Stressful Life Events", which is a broad category meaning pretty much anything bad that happens, the evidence was weaker. The previous meta-analyses only considered these studies.Ultimately, I think this analysis should remind us that the issue of 5HTTLPR is still "open", but I have concerns about the dataset. The fact that larger studies seem less likely to be positive is a classic warning sign of publication bias.The authors do consider this and say that they calculate that there would have to be over 700 unpublished, negative studies out there, in order to make the overall data negative. They also find that you could ignore the smallest 45 studies and still find a result. But still. Something doesn't feel right. Maybe I just have the wrong 5HTTLPR variant.Karg K, Burmeister M, Shedden K, & Sen S (2011). The Serotonin Transporter Promoter Variant (5-HTTLPR), Stress, and Depression Meta-analysis Revisited: Evidence of Genetic Moderation. Archives of general psychiatry, 68 (5), 444-54 PMID: 21199959... Read more »
Karg K, Burmeister M, Shedden K, & Sen S. (2011) The Serotonin Transporter Promoter Variant (5-HTTLPR), Stress, and Depression Meta-analysis Revisited: Evidence of Genetic Moderation. Archives of general psychiatry, 68(5), 444-54. PMID: 21199959
A few months ago, Henry et al. (2011a) published a truly remarkable study that analyzed the phytoliths and starch grains that had gotten encrusted in the dental calculus (i.e., plaque) of three Neanderthal individuals, two from the site of Spy (Belgium), and another from the site of Shanidar (Iraq). Their study provided the first direct evidence that plant foods were an integral part of the ... Read more »
Henry, A., Brooks, A., & Piperno, D. (2010) Microfossils in calculus demonstrate consumption of plants and cooked foods in Neanderthal diets (Shanidar III, Iraq; Spy I and II, Belgium). Proceedings of the National Academy of Sciences, 108(2), 486-491. DOI: 10.1073/pnas.1016868108
Henry, A., Brooks, A., & Piperno, D. (2011) Reply to Collins and Copeland: Spontaneous gelatinization not supported by evidence. Proceedings of the National Academy of Sciences. DOI: 10.1073/pnas.1104199108
Science has a post on their website about a little study (Gillespie et al. 2009) that came out a couple of years ago that applied some key biogeographical principles to provide a prediction of where Osama bin Laden might have been hiding. The paper was discussed in Scientific American when if first came out, but now has received a ton of attention because the authors' predicted hiding place for ... Read more »
Banks, W., Zilhão, J., d'Errico, F., Kageyama, M., Sima, A., & Ronchitelli, A. (2009) Investigating links between ecology and bifacial tool types in Western Europe during the Last Glacial Maximum. Journal of Archaeological Science, 36(12), 2853-2867. DOI: 10.1016/j.jas.2009.09.014
Lozier, J., Aniello, P., & Hickerson, M. (2009) Predicting the distribution of Sasquatch in western North America: anything goes with ecological niche modelling. Journal of Biogeography, 36(9), 1623-1627. DOI: 10.1111/j.1365-2699.2009.02152.x
I have to admit this made me laugh.
So, it's kind of a silly comic, definitely good for a few chuckles. Yet, when you take a second to think about it, there's a lot packed into it. In two little panels, the cartoonist manages to bring up two of the biggest misconceptions about prheistoric hunter-gatherers: 1) that hunter-gatherers spend only a small amount of ... Read more »
Bird-David, N. (1992) Beyond "The Original Affluent Society": A Culturalist Reformulation. Current Anthropology, 33(1), 25. DOI: 10.1086/204029
Mellars, P. (2005) The impossible coincidence. A single-species model for the origins of modern human behavior in Europe. Evolutionary Anthropology, 14(1), 12-27. DOI: 10.1002/evan.20037
A little while ago, someone contacted me asking if there was any evidence that Neanderthals had ever used coal. This is an interesting question, and one about which there is only little available information. In fact, there is almost no evidence of Neanderthals using coal, but the proof that does exist is very intriguing. The single instance comes from the Mousterian site of Les Canalettes, ... Read more »
Goldberg, P., & Sherwood, S. (2006) Deciphering human prehistory through the geoarcheological study of cave sediments. Evolutionary Anthropology, 15(1), 20-36. DOI: 10.1002/evan.20094
Roebroeks W, & Villa P. (2011) On the earliest evidence for habitual use of fire in Europe. Proceedings of the National Academy of Sciences of the United States of America, 108(13), 5209-14. PMID: 21402905
Théry, I., J. Gril, J.L. Vernet, L. Meignen, and J. Maury. (1996) Coal used for Fuel at Two Prehistoric Sites in Southern France: Les Canalettes (Mousterian) and Les Usclades (Mesolithic). Journal of Archaeological Science, 23(4), 509-512. DOI: 10.1006/jasc.1996.0048
By now, you're all way too familiar with the Egyptian Facebook activism. And everybody and his sister has spent the last year-and-a-half discussing how wrong was Malcolm Gladwell in dismissing Moldovan Twitter activism. And millions of you have smiled at Gaddafi's crazy rant against Tunisian Wikileaks activism. But I'm sure the notion of Avatar activism appeals to a more restricted audience.... Read more »
Mark Deuze. (2010) Survival of the mediated. Journal of Cultural Science, 3(2). info:/
Was a young British woman murdered by Romans?... Read more »
What is learning?
Most psychologists (indeed, most people in general) would agree that learning is the acquisition of new knowledge, or new behaviors, or new skills. Hungarian psychologists Gergely and Csibra offer a deceptively simple description: "Learning involves acquiring new information and using it later when necessary." What this means is that learning requires the generalization of information to new situations - new people, objects, locations, or events. The problem is that any particular piece of information that a human or animal receives is situated within a particular context. Learning theorists refer to this as the problem of induction. Most learning theories invoke statistical learning mechanisms to account for this: as infants or animals have experiences in the world, they can identify correlations among events or encounters, and use those statistical correlations to form the basis of generalizations for novel events or encounters. However, this does not explain the situations in which infants rapidly learn information after only one or a few instances - certainly not enough time for any statistical learning mechanism to provide reliable information. Human communication might provide a shortcut.
Gergely and Csibra offer the following examples:
If I point at two aeroplanes and tell you that 'aeroplanes fly', what you learn is not restricted to the particular aeroplanes you see or to the present context, but will provide you generic knowledge about the kind of artefact these planes belong to that is generalizable to other members of the category and to variable contexts... If I show you by manual demonstration how to open a milk carton, what you will learn is how to open that kind of container (i.e. you acquire kind-generalizable knowledge from a single manifestation). In such cases, the observer does not need to rely on statistical procedures to extract the relevant information to be generalized because this is selectively manifested to her by the communicative demonstration.
The key here is that the learner does not need to statistically infer the generalizable information. Rather, the generalizability of the information is indicated within the communicative interaction itself. You don't tell the child "that airplane is flying"; you say "airplanes fly." This sort of teaching is not restricted to linguistic communication, as in the case of the milk carton.
What Gergely and Csibra are hypothesizing is that human communication is an evolutionary adaptation designed to aid in the transmission of generic knowledge between individuals. Specifically, they speculate that the emergence of tool-making led to the selection for the capacity for the communication of generic knowledge, during hominin evolution. The argument is that observational learning mechanisms would not be sufficient for the cognitively opaque process of making and using tools.
What does this mean?
Read the rest of this post... | Read the comments on this post...... Read more »
A parrel bead from the Mary Rose warship goes up with the Endeavour shuttle launch.... Read more »
L. Bell, J. Lee-Thorp, & A. Elkerton. (2009) The sinking of the Mary Rose warship: a medieval mystery solved?. Journal of Archaeological Science, 166-173. DOI: 10.1016/j.jas.2008.08.006
A. Millard, & H. Schroeder. (2010) 'True British sailors': a comment on the origin of the men of the Mary Rose. Journal of Archaeological Science, 37(4), 680-682. info:/
By now, you've surely heard all the media hoopla about the alleged 'gay caveman' found in the Czech Republic that's been all over the news and internet for the past few weeks. Ugh! Y'know, I just got done reading Ben Goldacre's fantastic book Bad Science in which he bemoans (and entertainingly skewers!) the way medical findings are consistently distorted in the media, where flashy headlines seem ... Read more »
Potter, J., & Chuipka, J. (2010) Perimortem mutilation of human remains in an early village in the American Southwest: A case for ethnic violence. Journal of Anthropological Archaeology, 29(4), 507-523. DOI: 10.1016/j.jaa.2010.08.001
This Post is a reaction on the Post from “Ariel Cast out Caliban” by Eric Michael Johnson.There are many things in the world that annoy me: People in the bus who desperately hammer on the “stop” button to open the door, Professors who seem to know where my exact interests are although they haven’t talked in years and stupid ideologies which use biological examples to justify their view on the world. Although I’d love to talk about all those things (especially the first one) let’s stick to the third one for now.Every now and then, I encounter the following sentence in some way or another: “We should be like Bonobos.”What’s really interesting is that the extremes of what could be called “human nature” are represented by our closest living relatives: Chimpanzees and Bonobos, at least if we rely on popular representations of those two species. Chimpanzees are usually presented as egoistic, brutal and aggressive. Whether Bonobos are the ultimate pacifists, their groups are led by the female individuals and conflicts and stress are usually resolved by some way of sexual interaction -instead of just bashing the head of a rival or tearing apart a helpless Colobus Monkey.One of my favourite German biologists, Hubert Markl wrote in 1983 that all models on human nature usually have two aspects. The first one is the description of the present state of human nature, which is always pretty negative. The second one is the ideologically tainted vision of how humanity should be.If we use this model on our closest relatives, the Chimpanzees represent our present state, while the Bonobos is the Vision of what we should become. From time to time I encounter this case, be it in the media or from people I meet and it might come up again in the next time, after some of the results of this study from Perelman et al. (2011) get more public attention.This study, which deals with the Phylogenetic relationships of all primates, found that after the split between Chimpanzees and Bonobos, there was a higher rate of Change within the Genome of Chimpanzees as within the one of Bonobos. To make a long story short: This higher rate of change could lead to the conclusion that Bonobos are closer related to us, then Chimpanzees. Until now it was assumed that both species are equally related to us.This of course changes everything! Our closely related living relative is the ultimate example for altruism and cooperation. The true picture of our own nature! Once again, Man cut himself from his own natural heritage. Now we simply have to return to our own biological roots and all our problems are solved! I’d bet a large amount of money that someone will write something like that, just a little more elaborated and maybe a little more esoteric. Maybe I should write this stuff myself, put in a book and sell it to bolster my very slim budget.Jokes aside, my point is as follows:Both Chimpanzees and Bonobos are just models for our own ancestors. Those Models fit in some cases more and in some cases less well on our past. We can’t just transfer our observations on present day animals into the past, just to help us to support some kind of weird ideology, as we can’t use them to justify acts of brutality against ourselves.Furthermore, these genetic differences between chimpanzees and Bonobos are by now just statistical differences. We have no Idea if those differences are within regions which are related to behaviour or not.If we look at ourselves, we can see that we’re capable of both extremes: exceptional brutality as well as exceptional altruism. Bonobos and Chimpanzees could help us to understand how we acclaimed those behaviours and how they’re funded in our own biological heritage. Sure, there’s no potentially World-saving conclusion within this stuff, but we need it, if we want to understand our biological “nature”.Ideologies are always made by humans; and Primates, especially apes, were always used as a screen on which we can project ourselves on. The Chimpanzees were used for all that’s negative about us, while the Bonobos stand for everything positive. But we must not forget that both species are not “unfinished humans” or “almost human”, they are Apes. They got their own history, as we do. Their history might help us to understand our own history, and therefore our “nature”, in a much better way, but as closely as we’re related to them, they can never be role models for us.References:Markl, H. (1983) Wie unfrei ist der Mensch? Von der Natur in der Geschichte. In: Markl, H. (ed.). Natur und Geschichte. R. Oldenbourg, München, Wien. p. 11-40.Perelman P, Johnson WE, Roos C, Seuánez HN, Horvath JE, Moreira MA, Kessing B, Pontius J, Roelke M, Rumpler Y, Schneider MP, Silva A, O'Brien SJ, & Pecon-Slattery J (2011). A molecular phylogeny of living primates. PLoS genetics, 7 (3) PMID: 21436896... Read more »
A new paper on raised field agriculture was published on line last week in the journal Ecological Engineering. The title, “Ecological engineers ahead of their time: The functioning of pre-Columbian raised-field agriculture and its potential contributions to sustainability today”, is a bit misleading. You would think it is just another paper claiming that the re-habilitation of raised field agriculture will provide means for sustainable, highly productive, flood/drought proof, politically correct and environment friendly tropical agriculture… ... Read more »
D. Renard, J. Iriarte, J.J. Birk, S. Rostain, B. Glaser, & D. McKey. (2011) Ecological engineers ahead of their time: The functioning of pre-Columbian raised-field agriculture and its potential contributions to sustainability today. Ecological Engineering. info:/
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