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  • October 13, 2010
  • 03:35 AM
  • 730 views

The revenge of history

by Jeremy in Agricultural Biodiversity Weblog

Three papers today which look into the role of history in determining patterns of diversity, at the species and genetic level. I don’t have much time today, so descriptions will have to be quick and dirty for now. In Molecular Ecology, Hoban et al. used microsatellites to genotype 29 populations of Juglans cinerea from throughout [...]... Read more »

  • October 11, 2010
  • 04:40 PM
  • 964 views

My IVF story: conclusions

by Kate Clancy in Context & Variation

I discuss aging and reproductive health, reproductive choice, and the naturalistic fallacy in my concluding post on IVF.... Read more »

  • October 11, 2010
  • 12:52 PM
  • 3,211 views

What Are Those Darned Neanderthals Up to Now?

by Krystal D'Costa in Anthropology in Practice



Scene from the Neanderthal diorama at the American Museum of Natural History.
Not shown: Male Neanderthal figure holding tool.
The Neanderthal story is quickly becoming a favorite serial—who knows what new drama the day will bring! Once regarded as brutish and stupid, it was accepted that they could not compete technologically and socially with early modern human (EMH) populations and were eradicated as the latter spread throughout the globe. But in the last few years, the reputation of our Neaderthal cousins has changed. In fact, we've learned that they were surprisingly like us in many ways: they painted shells for jewelry, provided care for those in need, and had a sophisticated tool industry (see more here). Their diorama at the American Museum of Natural History shows them in a family unit. Their genome has revealed few conspicuous differences, instead demonstrating that Neanderthals may have in fact left a trace of themselves in our own genes.
The Neanderthal story stimulates the imagination because for all the similarities and newly credited skills the fact remains that they disappeared completely (in geological terms), leaving the earth to Homo sapiens. And I think part of the reason we're so intrigued is that on one level we wonder as a species whether we could disappear in the same way—gone but for a few instances in the fossil record. The Discovery Channel has done an excellent job of presenting the disaster possibilities: an asteroid could strike, global warming could do us in, the sun will eventually die, and so on. All the scenarios present events with immense environmental impact that would threaten our ability to find sustenance and cripple our overall well-being. A recent paper in Current Anthropology proposes that Neanderthals fell victim to one such devastating environmental event—volcanic activity—and illustrates the ways the fallout from the event would have made their environment inhospitable.


The skeleton called the "Ring Lady"
unearthed in Herculaneum.
Credit: Wikipedia
Neanderthals lived in Europe from about 400,000 to about 40,000 years ago. And they were used to adverse conditions: their environment was a very cold one, and may have included a severe ice age known as glacial period OIS 4. Like EMHs, they were accustomed to and could manage the climatic variables of the northern European landscape they frequented. For example, they clothed themselves against the elements. However, we know from Vesuvius that volcanic activity can present an insurmountable challenge. The charred remains of Pompeii are a testament to the speed and finality with which ash can cover the surrounding area. And ash is a troublesome thing: it spreads easily, carrying its effects far and wide. When the Eyjafjallajökull Volcano erupted earlier this year, NASA documented the spread of the ash over the Atlantic. Ash can have a cooling effect, causing crop failures and widespread famine. If it reaches the stratosphere (upper atmosphere), these effects can be prolonged as sulfur lingers in a reflective layer above the earth keeping much needed sunlight from the planet's surface (and eventually falling as acid rain as an added bonus).
Researchers Golovanova et. al. (2010) believe that Neanderthals may have been overcome by the combined effects of three successive volcanic explosions, the largest of which would have been the Campanian Ignimbrite (CI) eruption from the Phlegraean Fields in Italy:We offer the hypothesis that the Neanderthal demise occurred abruptly (on a geological timescale) at around 40,000 BP after the most powerful volcanic activity in western Eurasia during the period of Neanderthal evolutionary history. We further hypothesize that this catastrophe not only drastically destroyed the ecological niches of Neanderthal populations but also caused their mass physical depopulation in most of their habitation areas across Europe and the Near East. This loss of viable source populations may have significantly contributed to the eventual extinction of Neanderthals throughout their range (673).Using soil samples from Mezmaiskaya Cave, a well-preserved site of occupation for both Neanderthals and EMHs in the Northern Caucasus, Golovanova et. al. were able to trace periods of occupation in the area, noting significantly that activity dropped in correlation to volcanic soil layers. This information not only demonstrates when the site was being used, but also provides us with a foundation with which to understand the apparent transition from Neanderthal occupation to EMH occupation of the region.
Soil samples from Mezmaiskaya Cave have revealed two distinct layers of volcanic ash, suggesting that the ash accumulated as a result of two different eruptions—neither of which are the CI eruption:Geochemical analysis suggests that eruptions in the Elbrus volcanic province between 45,000 and 40,000 years ago are the most likely sources of the ash in later 2B-1 at Mezmaiskaya Cave ... The basaltic chemical composition of the ash in layer 1D is closer to that of volcanic rocks of Mt. Kazbek in the Central Caucasus. The explosive volcanoes of Mt. Kazbek in the Terek River upper valley are the most likely sources of the ash in layer 1D at Mezmaiskaya (660).Soil analysis also suggests climatic shifts following the volcanic events as well, with low levels of pollen concentration and little arboreal spores (660). This would have made the area unsuitable for foraging and inhospitable for any animals that frequented the area as well, which in turn resulted in diminished activity in and around Mezmaiskaya. What is interesting, however, is that activity seems to have resumed at Mezmaiskaya following the Elbrus eruption:The first volcanic eruption produced ash in the later MP [Middle Paleolithic] layer 2B-1 and essentially resulted in the deterioration of ecological conditions in the region ... The intensity of site use increased, however, during the accumulation of the upper MP layers 2A and 2 when the climate became cool and wet. Although the lithic industry changed slightly after the environmental crisis of layer 2B-1, it still remained typically MP Eastern Micoquian. Skeletal and mtDNA evidence indicates that Neanderthals produced both the earlier and the later MP industries at Mezmaiskaya (667).The Kazbek eruption proved to have been more serious. The ash layer is about 0.7 m thick, and following the eruption signs of habitation are sparse. The CI eruption fits into this puzzle because it had a widespread ... Read more »

Liubov Vitaliena Golovanova,, & Vladimir Borisovich Doronichev, Naomi Elansia Cleghorn, Marianna Alekseevna Koulkova, Tatiana Valentinovna Sapelko, M. Steven Shackley. (2010) Significance of Ecological Factors in the Middle to Upper Paleolithic Transition. Current Anthropology, 655-691. info:/10.1086/656185

  • October 11, 2010
  • 10:18 AM
  • 1,188 views

Paleo Diet for Heart Patients With Diabetes and Prediabetes

by Steve Parker, M.D. in Diabetic Mediterranean Diet Blog

A Paleolithic diet lowered blood sugar levels better than a control diet in coronary heart disease patients with elevated blood sugars, according to Swedish researchers reporting in 2007. About half of patients with coronary heart disease have abnormal glucose (blood sugar) metabolism.  Lindeberg and associates wondered if a Paleolithic diet (aka “Old Stone Age,” “caveman,” or ancestral human diet) [...]... Read more »

  • October 11, 2010
  • 09:31 AM
  • 1,037 views

The 20th Anniversary of Steven Pinker & Paul Bloom: Natural Language and Natural Selection (1990)

by Michael in A Replicated Typo 2.0


The day before yesterday Wintz mentioned two important birthdays in the field of language evolution (see here): First, Babel’s Dawn turned four, and second, as both Edmund Blair Bolles and Wintz pointed out, Steven Pinker‘s and Paul Bloom‘s seminal paper “Natural Language and Natural Selection” (preprint can be found here) has its 20th anniversary.
Wintz wrote that he . . . → Read More: The 20th Anniversary of Steven Pinker & Paul Bloom: Natural Language and Natural Selection (1990)... Read more »

Pinker, Steven, & Bloom, Paul. (1990) Natural Language and Natural Selection. Behavioral and Brain Sciences, 13(4), 707-726. info:/

  • October 11, 2010
  • 09:05 AM
  • 689 views

Why I'm out online

by Jeremy Yoder in Denim and Tweed

Exactly a year ago today, I came out of the online closet. Now it's another National Coming Out Day, and it seems like as good a time as any to think out loud about why I made that decision.
.flickr-photo { }.flickr-frameright { float: right; text-align: left; margin-left: 15px; margin-bottom: 15px; width:40%;}.flickr-caption { font-size: 0.8em; margin-top: 0px; } Image borrowed from Wikipedia under fair use rationale.My reasons aren't going to surprise anyone who has even a passing familiarity with gay rights history:Familiarity breeds acceptance. This is mainly a political argument. It's widely accepted (and supported by ongoing public opinion surveying) that people who personally know GLBT folks are overwhelmingly more likely to support treating GLBT people like full citizens. The psychology isn't hard to understand—it's easy to hate the nebulous, faceless, unknown Gays; it's rather harder to hate your son, or your niece, the nice neighbors who let you borrow their lawnmower, or (I hope) the guy who writes that one not-entirely-terrible science blog you check every so often.
Gotta give'em hope. And an example. This is more personal. I grew up without knowing any out gay people, which was, to put it mildly, not helpful. I was, to paraphrase the Onion headline, The Only Homosexual in the World; I didn't have any of the support, or visible examples, that would've helped me think critically about my sexual orientation or imagine a future in which I was out, and happy about it. (Which I very much am, these days.) By being open about my orientation, maybe I can help someone else figure out his (or hers) in a way I couldn't, and even show that, as confusing and frequently miserable as growing up gay is, it gets better.
And if there's one impression I hope to give a confused, lonely (and presumably nerdy) gay kid reading D&T, it's that it did get better for this formerly confused, lonely (and unquestionably nerdy) gay kid. And a large part of how it got better, for me, has to do with going into science.

Evolutionary biology has turned out to be a good field for me, in this personal respect. When I started my first genuine biology-related internship, I was surrounded for the first time by people who didn't talk about gays in the hushed, scandalized tones I'd heard through a lot of my childhood and schooling. Biologists are as human as the next ape descendent, but they're also a generally open-minded bunch who tend to be more interested in the quality of your work than what you do after you leave the lab. And, for what are probably obvious reasons, evolutionary biology doesn't attract the sort of people who hold doctrinaire conservative religious positions on any subject.

Evolutionary biology is also a pretty good academic discipline for me because evolutionary biology has something to say about sexual minorities, just as it has something to say about humans in general. Humans are biological beings, and we're part of an animal kingdom that exhibits a wide array of sexual behaviors, as elaborately documented by the evolutionary biologist Joan Roughgarden in her book Evolution's Rainbow. Exactly how to explain this diversity, particularly in the case of humans, is still quite controversial [$a]—but it's a question for which I have some expertise, and one I'd like to weave into the writing I do for D&T in the future.

References

Futuyma, D. (2005). Celebrating diversity in sexuality and gender. Evolution, 59 (5), 1156-9 DOI: 10.1111/j.0014-3820.2005.tb01052.x

Roughgarden, J. (2004). Evolution's Rainbow. Berkeley: University of California Press. Preview on Google Books.

... Read more »

  • October 11, 2010
  • 01:02 AM
  • 697 views

Welcome, Science Readers!

by teofilo in Gambler's House

In honor of the twentieth anniversary of the passage of NAGPRA, Science has an interesting special section of short articles on the impact of NAGPRA on archaeology and physical anthropology.  They’re all definitely worth reading, and free with an annoying registration.  Among them is an interview of Steve Lekson by Keith Kloor which is of [...]... Read more »

  • October 7, 2010
  • 09:45 PM
  • 481 views

Unique Strains of Yersinia pestis Caused the Black Death

by Michael Long in Phased

Barbara Bramanti (Johannes Gutenberg University, Germany) and coworkers present conclusive biochemical (DNA and protein) evidence that Yersinia pestis, of multiple and possibly extinct lineages, was responsible for the Black Death of medieval Europe. This news feature was written on October 7, 2010.... Read more »

Haensch, S., Bianucci, R., Signoli, M., Rajerison, M., Schultz, M., Kacki, S., Vermunt, M., Weston, D. A., Hurst, D., Achtman, M.... (2010) Distinct Clones of Yersinia pestis Caused the Black Death. PLoS Pathogens, 6(10). DOI: 10.1371/journal.ppat.1001134  

  • October 7, 2010
  • 09:50 AM
  • 904 views

Around the web: the dark side of behavioral biology

by Kate Clancy in Context & Variation

A link round-up on evolutionary psychology, rape, infanticide, and other nasty stuff.... Read more »

Thornhill, R, & Thornhill, NW. (1992) The evolutionary psychology of men's coercive sexuality. Behavioral and Brain Sciences, 363-421. info:/

  • October 7, 2010
  • 08:31 AM
  • 474 views

Israel and Palestine are Both Fighting Back...?

by Neuroskeptic in Neuroskeptic

There are three basic schools of thought on the Israel / Palestine thing.Those evil Israelis are out to destroy Palestine, and the Palestinians are just fighting back.Those evil Palestinians are out to destroy Israel, and the Israelis are just fighting back.It's a cycle of violence, where both sides are fighting back against the other.Which one you subscribe to depends mostly on where you were born. I'm not aware of many people who've changed their minds on this issue, perhaps because doing so would require a study of the last 2,500 years of history, religion and politics.Wouldn't it be handy if science could provide an answer? According to the authors of a new paper in Proceedings of the National Academy of Science, the "cycle" school is right: both sides are fighting back against the other: Both sides retaliate in the Israeli-Palestinian conflict.The authors (from Switzerland, Israel and the USA) took data on daily fatalities on both sides, and also of daily launches of Palestinian "Qassam" rockets at Israel. The data run from 2001, the start of the current round of unpleasantness, to late 2008, the Gaza War.They looked to see whether the number of events that happened on a certain day predicted the number of events caused by the other side on the following days, i.e. whether a Palestinian death caused the Palestinians to retaliate by firing more rockets and killing more Israelis, and vice versa.What happened? They found that both sides were more likely to launch attacks on the days following a death on their own side. The exception to this rule was that Israel did not noticeably retaliate against Qassam launches. This is perhaps because Qassams are so ineffective: out of 3,645 recorded launches, they killed 15 people.These graphs show the number of "extra" actions on the days following a event, averaged over the whole 8 years, according to a statistical method called the Impulse Response Function. Note that the absolute size of the effects is larger for the Israeli retaliations (the Y axis is bigger); there were a total of 4,874 Palestinian fatalities and 1,062 Israeli fatalitiesThe authors then used another method called Vector Autoregression to discover more about the relationship. In theory, this method controls for the past history of actions by a given side, so that it reveals the number of actions independently caused by the opposing side.the number of Qassams fired increases by 6% on the first day after a single killing of a Palestinian by Israel; the probability of any Qassams being fired increases by 11%; and the probability of any Israelis being killed by Palestinians increases by 10%. Conversely, 1 day after the killing of a single Israeli by Palestinians, the number of Palestinians killed by Israel increases by 9%, and the probability of any Palestinians being killed increases by 20%....retaliation accounts for a larger fraction of Palestinian compared with Israeli aggression: in the levels specification, 10% of all Qassam rockets can be attributed to prior Israeli attacks on Palestinians, but only 4% of killings of Palestinians by Israel can be attributed to prior Palestinian attacks on Israel.... 6% of all days on which Palestinians attack Israel with rockets, and 5% of all days on which they attack by killing Israelis, can be attributed to retaliation; in contrast, this is true for only 2% of all days on which Israel kills Palestinians.What are we to make of this? This is a good paper as far as it goes, and it casts doubt on earlier analyses finding that Israel is retaliating against Palestinians but not vice versa. However, the inherent problem with all of this research (beyond the fact that it's all based on correlations and can only indirectly imply causation), is that it focuses on individual acts of violence. The authors say, citing surveys, thatOver one half of Israelis and three quarters of Palestinians think the other side seeks to take over their land. When accounting for their own acts of aggression, Israelis often claim to be merely responding to Palestinian violence, and Palestinians often see themselves as simply reacting to Israeli violence.But I don't think many Israelis would argue that the IDF only kills individual Palestinians as a reflex reaction to a particular attack. They're claiming that the whole conflict is a defensive one, that the Palestinians are the aggressors, but that doesn't rule out their taking the initiative on a tactical level e.g. in destroying Palestinian military capabilities before they have a chance to attack. And vice versa on the other side.WW2 was a war of aggression by the Axis powers, but that doesn't mean that the Allies only killed Axis soldiers after they'd attacked a certain place. The Allies were on the offensive for the second half of the war, and eventually invaded the Axis's own homelands, but it was still a defensive war, because the Axis were responsible for it.For Israel and for Palestine, the other guys are to blame for the whole thing. Who's right, if anyone, is fundamentally a historical, political and ethical question, that can't be answered by looking at day-to-day variations in who's shooting when.Comment Policy: Please only comment if you've got something to say about this paper, or related research. Comments that are just making the case for or against Israel will get deleted.Haushofer J, Biletzki A, & Kanwisher N (2010). Both sides retaliate in the Israeli-Palestinian conflict. Proceedings of the National Academy of Sciences of the United States of America PMID: 20921415... Read more »

Haushofer J, Biletzki A, & Kanwisher N. (2010) Both sides retaliate in the Israeli-Palestinian conflict. Proceedings of the National Academy of Sciences of the United States of America. PMID: 20921415  

  • October 6, 2010
  • 05:04 PM
  • 742 views

My IVF story: after conception, being preggers

by Kate Clancy in Context & Variation

This is the second post of four on my experience with IVF and pregnancy, and my thinking on its broader meaning to the public and to anthropology. Find the first post here.PreggersA few weeks after the positive blood test, I had my ultrasound where we saw a tiny little bean and a beating heart. During this time I was having what felt like bad menstrual cramps. The nurse told me this was quite normal, but I still spent a lot of mental energy fretting over it. The rest of the first trimester was pretty uncomfortable. In addition to being exhausted, I was nauseous. I didn’t want to eat vegetables. In fact, all I really wanted was toast (gluten free, of course). I concocted a pretty awesome smoothie that I would drink once or twice a day, made of chocolate almond milk, peanut butter and ice cubes. It settled my stomach, and it’s probably because of those smoothies that I only lost four pounds.At this point we also transitioned from medical doctor care to a midwife. At first we were just given to the next available midwife in our practice. But when it became clear that in order to stay in that practice we’d have to have a hospital birth, we transferred to the Cambridge Birth Center in Cambridge, MA and the midwives there.Where to give birth and whyThe Cambridge Birth Center is a stand-alone birth center associated with (and across the street from) the Cambridge Hospital. There are no doctors, but you can get into the OR in four minutes for an emergency C-section if you need to (yes, they practice and time these things). So I was completely confident that, if I had a straightforward, low-risk pregnancy and labor, I would be best suited to the birth center, and if anything went wrong I was minutes from a doctor.We were a bit nervous about this decision, because of the stigma attached to IVF children. Do IVF pregnancies lead to more difficult pregnancies or labors? Are we going to have a child with greater or fewer limbs than the average? The reality is that, while the egg was fertilized in a rather special manner, a fertilized egg, then blastocyst, trophoblast, and so on that makes it to become a fetus, and then makes it trouble-free through the first trimester? That fetus is very, very likely to be healthy and normal.The other reason we were firm in our decision is that a number of interventions that are automatic upon entering a hospital are not physiologically necessary, and even increase the risk of later interventions. Pubic hair shaving is still a common practice in some hospitals, which is just plain dehumanizing. More common are continuous fetal monitoring and putting in an IV immediately. Continuous fetal monitoring is more likely to find false positives, which means it’s more likely to find pathology in a fetal heartbeat that goes up or down but resolves on its own naturally. IVs restrict movement and lower the barrier for a doctor to suggest, and a woman to agree to, pharmaceutical interventions. This is in addition to the many other criticisms I could launch but won’t because I find it all so exhausting.The biggest issue, for me, is that if you walk into a hospital you have at least a 33% chance of having a Cesarean section, and the reasons behind that are largely related to the ratcheting up of interventions as one intervention necessitates the next one. A C-section is major abdominal surgery. It takes a long time to recover. It is hard to breastfeed, it is hard to pick up your child, and you spend more days in the hospital. These are days when your sleep is more disrupted than when you’re home, and you increase your and your child’s chances of infection by being in a hospital, and extra days when you as a family could be figuring out a routine at home to make sure the mother isn’t the only one bonding to the new baby.Then there are indications that C-sections create health concerns for the baby as she gets older. Babies of C-sections have higher rates of allergy (i.e., Roduit et al 2009), asthma (i.e., Davidson et al 2010) and Celiac (gluten intolerance) (Decker et al 2010). I am a C-section baby myself and I have severe allergies, allergy-induced asthma, and gluten intolerance (a trifecta of awesomeness!). Given that I’ll be passing on some of the genetic proclivities for these things, I wasn’t too keen on giving my child the environmental components that would also increase her risk if I could avoid it.So we started seeing a midwife, and I got to know a different part of Cambridge better than I’d known before. I really fell in love with Inman Square.Going metaThroughout my pregnancy, I devoured popular books on pregnancy (good: anything by Sheila Kitzinger, bad: What to Expect When You’re Expecting) but also searched for a lot of information on PubMed and kept an Endnote library devoted to my results. I read about the craptastic relationship between symphysis-fundal height measurements (this is when they use measuring tape to measure the size of your belly) and birth weight (i.e., Johnstone et al 1996) – even in those studies that found a statistical correlation, SFH often explained very little of the variance in birth weight. I read about exercise during pregnancy (de Groot et al 1994) – and I played soccer through my first trimester, jogged through my second, and worked out five days a week through the whole pregnancy, up to the day before my due date. I read about meconium, I read about fetal monitoring, I read about maternal stress. When I wasn’t working I was reading, and when I wasn’t reading I was exercising. All the other time I was in prenatal appointments or sleeping.Of course, as excruciatingly long as the pregnancy felt, as boring and normal and yet delightful as it was, it did eventually come to a close. Family flew in from out of town to be around for my due date, and there was a lot of pressure – joking, but pressure nonetheless – to produce offspring before everyone left. When my due date brought with it the occasional half-hearted contraction, nothing I hadn’t felt before, I went to bed disappointed.The next morning I woke up, got out of bed, and my water broke all over the bedroom floor.* * *Next time, I’ll talk about the joys of drug-free labor.ReferencesDavidson, R., Roberts, S., Wotton, C., & Goldacre, M. (2010). Influence of maternal and perinatal factors on subsequent hospitalisation for asthma in children: evidence from the Oxford record linkage study BMC Pulmonary Medicine, 10 (1) DOI: 10.1186/1471-2466-10-14Decker, E., Engelmann, G., Findeisen, A., Gerner, P., Laass, M., Ney, D., Posovszky, C., Hoy, L., & Hornef, M. (2010). Cesarean Delivery Is Associated With Celiac Disease but Not Inflammatory Bowel Disease in Children PEDIATRICS, 125 (6) DOI: 10.1542/peds.2009-2260de Groot LC, Boekholt HA, Spaaij CK, van Raaij JM, Drijvers JJ, van der Heijden LJ, van der Heide D, & Hautvast JG (1994). Energy balances of healthy Dutch women before and during pregnancy: limited scope for metabolic adaptations in pregnancy. ... Read more »

Decker, E., Engelmann, G., Findeisen, A., Gerner, P., Laass, M., Ney, D., Posovszky, C., Hoy, L., & Hornef, M. (2010) Cesarean Delivery Is Associated With Celiac Disease but Not Inflammatory Bowel Disease in Children. PEDIATRICS, 125(6). DOI: 10.1542/peds.2009-2260  

de Groot LC, Boekholt HA, Spaaij CK, van Raaij JM, Drijvers JJ, van der Heijden LJ, van der Heide D, & Hautvast JG. (1994) Energy balances of healthy Dutch women before and during pregnancy: limited scope for metabolic adaptations in pregnancy. The American journal of clinical nutrition, 59(4), 827-32. PMID: 8147326  

Johnstone, F., Prescott, R., Steel, J., Mao, J., Chambers, S., & Muir, N. (1996) Clinical and ultrasound prediction of macrosomia in diabetic pregnancy. BJOG: An International Journal of Obstetrics and Gynaecology, 103(8), 747-754. DOI: 10.1111/j.1471-0528.1996.tb09868.x  

Roduit, C., Scholtens, S., de Jongste, J., Wijga, A., Gerritsen, J., Postma, D., Brunekreef, B., Hoekstra, M., Aalberse, R., & Smit, H. (2009) Asthma at 8 years of age in children born by caesarean section. Thorax, 64(2), 107-113. DOI: 10.1136/thx.2008.100875  

  • October 6, 2010
  • 04:10 PM
  • 778 views

My IVF story: after conception, being preggers

by Kate Clancy in Laboratory for Evolutionary Endocrinology

This is the second of a four part series on IVF, pregnancy and labor.... Read more »

Decker, E., Engelmann, G., Findeisen, A., Gerner, P., Laass, M., Ney, D., Posovszky, C., Hoy, L., & Hornef, M. (2010) Cesarean Delivery Is Associated With Celiac Disease but Not Inflammatory Bowel Disease in Children. PEDIATRICS, 125(6). DOI: 10.1542/peds.2009-2260  

de Groot LC, Boekholt HA, Spaaij CK, van Raaij JM, Drijvers JJ, van der Heijden LJ, van der Heide D, & Hautvast JG. (1994) Energy balances of healthy Dutch women before and during pregnancy: limited scope for metabolic adaptations in pregnancy. The American journal of clinical nutrition, 59(4), 827-32. PMID: 8147326  

Johnstone, F., Prescott, R., Steel, J., Mao, J., Chambers, S., & Muir, N. (1996) Clinical and ultrasound prediction of macrosomia in diabetic pregnancy. BJOG: An International Journal of Obstetrics and Gynaecology, 103(8), 747-754. DOI: 10.1111/j.1471-0528.1996.tb09868.x  

Roduit, C., Scholtens, S., de Jongste, J., Wijga, A., Gerritsen, J., Postma, D., Brunekreef, B., Hoekstra, M., Aalberse, R., & Smit, H. (2009) Asthma at 8 years of age in children born by caesarean section. Thorax, 64(2), 107-113. DOI: 10.1136/thx.2008.100875  

  • October 6, 2010
  • 11:27 AM
  • 1,424 views

Digital Literacy at What Price?

by Krystal D'Costa in Anthropology in Practice

A cultural and cognitive shift is well underway in terms of how we access and process information via digital media. And a recent study confirms our suspicions: though we are becoming more tech savvy, it may be at the expense of creative and critical thinking. Researchers from the University of Israel (2009), tested digital literacy with a group in 2002. In 2007, they tested this same group again and found statistically significant changes on the test scores.  Is this further proof of the widening double digital divide?

Digital literacy is defined in this study as the "ability to employ a wide range of cognitive and emotional skills in using digital technology" (713). This range covers six skills:Photovisual literacy: ability to work with digital environments that employ graphical communication, such as user interfaces.
Reproduction literacy: ability to create authentic, meaningful  written and artwork by reproducing and manipulating digital media.
Branding literacy: ability to construct knowledge by nonlinear navigation through knowledge domains (i.e., hyperlinks).
Information literacy: ability to consume information critically and sort out false and biased views.
Socioemotional literacy: ability to communicate in online communication platforms (e.g., chat, bulletin boards).
Real Time Thinking: ability to process and evaluate large amounts of information in real time, such as in computer games and chatrooms.
Participants were given tasks in four of these areas (photovisual, reproduction, branching, and information). When tested five years later, and compared to a control group, there was a significant change in digital skills.


From Changes Over Time in Digital Literacy, 2009.
© CyberPsychology and Behavior.
The results demonstrate that all age groups in the study responded similarly: all were able to demonstrate an increased grasp of technology. However, on tasks that creativity and critical thinking (reproduction and information), the scores for younger participants dipped slightly in comparison to adults, whose scores increased.
With the ever increasing amount of information readily available via hyperlinks, and a growing willingness to use digital media to access that information, how can we encourage digital literacy and maintain critical thinking skills? How can we change students' relationships with information? And how can we ensure that everyone has access to the tools necessary to build a solid foundation of digital media?
Does the diminished critical thinking skill will add another level to the digital divide: those without access, those with access but with poor understanding of the tools, and those with access and understanding. What kinds of issues do you foresee these groups facing?
Cited:Eshet-Alkalai, Y., & Chajut, E. (2009). Changes Over Time in Digital Literacy CyberPsychology & Behavior, 12 (6), 713-715 DOI: 10.1089/cpb.2008.0264

... Read more »

Eshet-Alkalai, Y., & Chajut, E. (2009) Changes Over Time in Digital Literacy. CyberPsychology , 12(6), 713-715. DOI: 10.1089/cpb.2008.0264  

  • October 5, 2010
  • 08:50 PM
  • 651 views

A Lack of Energy May Increase the Size of Human Civilization

by Michael Long in Phased

John DeLong (Yale University, United States) and coworkers present a paradoxical finding, namely that a lack of available energy supplies will enable the human population to keep on growing, rather than stabilize, in the coming decades. This news feature was written on October 5, 2010.... Read more »

  • October 5, 2010
  • 09:51 AM
  • 563 views

Family and Culture Affect Whether Intelligence Leads to Education

by APS Daily Observations in Daily Observations

Intelligence isn’t the only thing that affects your education: family, culture, and other factors are important, too. A new study published in Psychological Science, compared identical and fraternal twins in ... Read more »

Johnson, W., Deary, I.J., Silventoinen, K., Tynelius, P., & Rasmussen, F. (2010) Family background buys an education in Minnesota but not in Sweden. Psychological science : a journal of the Association for Psychological Science / APS. PMID: 20679521  

  • October 4, 2010
  • 11:37 PM
  • 1,047 views

The Ignobel Prizes – A computational study of the Peter Principle

by Croor Singh in Learning to be Terse

This year’s Ignobel Prizes have been announced. Among the winners are an engineering solution to the problem of collecting whale snot, a prize in Medicine for the people who discovered that asthma can be treated by putting the patient on a roller coaster (I’m having a hard time imagining clinical trials for this!), a Peace [...]... Read more »

Pluchino, A., Rapisarda, A., & Garofalo, C. (2010) The Peter principle revisited: A computational study. Physica A: Statistical Mechanics and its Applications, 389(3), 467-472. DOI: 10.1016/j.physa.2009.09.045  

  • October 4, 2010
  • 12:35 AM
  • 540 views

ET Impact Probably Didn’t Wipe Out Clovis

by cfeagans in A Hot Cup of Joe



In a paper published in PNAS in 2007[1], Firestone and others suggested that there was evidence that shows that the Younger Dryas period in the Northern Hemisphere was interrupted by a barrage of extraterrestrial comets at about 12.9 ka. This … Continue reading →... Read more »

  • October 1, 2010
  • 12:26 PM
  • 662 views

Sex, Evolution, and the Case of the Missing Polygamists

by Eric Michael Johnson in The Primate Diaries in Exile

The latest stop in the #PDEx tour is being hosted at Psychology Today by Sex at Dawn:There is no greater mystery in human evolution than the origins of our sexuality. Following the trail of clues available researchers have independently concluded that humans evolved through systems of monogamy, polygyny, as well as polyamory. However only one can be the culprit and, like a detective interrogating multiple suspects, the solution ultimately depends on which account you're willing to believe. Last year Owen Lovejoy made the case for monogamy based on the fossil remains of the early human ancestor Ardipithecus ramidus. Meanwhile, Christopher Ryan and Cacilda Jethá have argued that polyamory (or, more precisely, a multimale-multifemale mating system) is the most likely scenario from an analysis that emphasized anthropology, behavioral biology, and physiology. To further complicate matters the third suspect in this mystery, polygyny, has been the conclusion from scientists conducting DNA analyses. These conflicting accounts therefore require careful detective work in order to determine which story is the most convincing.Read the rest of the post here and stay tuned for the next entry in The Primate Diaries in Exile tour.Hammer, M., Mendez, F., Cox, M., Woerner, A., & Wall, J. (2008). Sex-Biased Evolutionary Forces Shape Genomic Patterns of Human Diversity PLoS Genetics, 4 (9) DOI: 10.1371/journal.pgen.1000202... Read more »

  • October 1, 2010
  • 05:17 AM
  • 645 views

Genes for ADHD, eh?

by Neuroskeptic in Neuroskeptic

The first direct evidence of a genetic link to attention-deficit hyperactivity disorder has been found, a study says.Wow! That's the headline. What's the real story?The research was published in The Lancet, and it's brought to you by Wilson et al from Cardiff University: Rare chromosomal deletions and duplications in attention-deficit hyperactivity disorder.The authors looked at copy-number variations (CNVs) in 410 children with ADHD, compared to 1156 healthy controls. A CNV is simply a catch-all term for when a large chunk of DNA is either missing ("deletions") or repeated ("duplications"), compared to normal human DNA. CNVs are extremely common - we all have a handful - and recently there's been loads of interest in them as possible causes for psychiatric disorders.What happened? Out of everyone with high quality data available, 15.6% of the ADHD kids had at least one large, rare CNV, compared to 7.5% of the controls. CNVs were especially common in children with ADHD who also suffered mental retardation (defined as having an IQ less than 70) - 36% of this group carried at least one CNV. However, the rate was still elevated in those with normal IQs (11%).A CNV could occur anywhere in the genome, and obviously what it does depends on where it is - which genes are deleted, or duplicated. Some CNVs don't cause any problems, presumably because they don't disrupt any important stuff.The ADHD variants were very likely to affect genes which had been previously linked to either autism, or schizophrenia. In fact, no less than 6 of the ADHD kids carried the same 16p13.11 duplication, which has been found in schizophrenic patients too.So...what does this mean? Well, the news has been full of talking heads only too willing to tell us. Pop-psychologist Oliver James was on top form - by his standards - making a comment which was reasonably sensible, and only involved one error:Only 57 out of the 366 children with ADHD had the genetic variant supposed to be a cause of the illness. That would suggest that other factors are the main cause in the vast majority of cases. Genes hardly explain at all why some kids have ADHD and not others.Well, there was no single genetic variant, there were lots. Plus, unusual CNVs were also carried by 7% of controls, so the "extra" mutations presumably only account for 7-8%. James also accused The Lancet of "massive spin" in describing the findings. While you can see his point, given that James's own output nowadays consists mostly of a Guardian column in which he routinely over/misinterprets papers, this is a bit rich.The authors say thatthe findings allow us to refute the hypothesis that ADHD is purely a social construct, which has important clinical and social implications for affected children and their families.But they've actually proven that "ADHD" is a social construct. Yes, they've found that certain genetic variants are correlated with certain symptoms. Now we know that, say, 16p13.11-duplication-syndrome is a disease, and that its symptoms include (but aren't limited to) attention deficit and hyperactivity. But that doesn't tell us anything about all the other kids who are currently diagnosed with "ADHD", the ones who don't have that mutation."ADHD" is evidently an umbrella term for many different diseases, of which 16p13.11-duplication-syndrome is one. One day, when we know the causes of all cases of attention deficit and hyperactivity symptoms, the term "ADHD" will become extinct. There'll just be "X-duplication-syndrome", "Y-deletion-syndrome" and (because it's not all about genes) "Z-exposure-syndrome".When I say that "ADHD" is a social construct, I don't mean that people with ADHD aren't ill. "Cancer" is also a social construct, a catch-all term for hundreds of diseases. The diseases are all too real, but the concept "cancer" is not necessarily a helpful one. It leads people to talk about Finding The Cure for Cancer, for example, which will never happen. A lot of cancers are already curable. One day, they might all be curable. But they'll be different cures.So the fact that some cases of "ADHD" are caused by large rare genetic mutations, doesn't prove that the other cases are genetic. They might or might not be - for one thing, this study only looked at large mutations, affecting at least 500,000 bases. Given that even a deletion or insertion of just one base in the wrong place could completely screw up a gene, these could be just the tip of the iceberg.But the other problem with claiming that this study shows "a genetic basis for ADHD" is that the variants overlapped with the ones that have recently been linked to autism, and schizophrenia. In other words, these genes don't so much cause ADHD, as protect against all kinds of problems, if you have the right variants.If you don't, you might get ADHD, but you might get something else, or nothing, depending on... we don't know. Other genes and the environment, presumably. But "7% of cases of ADHD associated with mutations that also cause other stuff" wouldn't be a very good headline...N. M. Williams et al (2010). Rare chromosomal deletions and duplications in attention deficit hyperactivity disorder: a genome-wide analysis The Lancet... Read more »

N. M. Williams et al. (2010) Rare chromosomal deletions and duplications in attention deficit hyperactivity disorder: a genome-wide analysis. The Lancet. info:/

  • September 30, 2010
  • 11:29 AM
  • 513 views

Around the web: sexuality

by Kate Clancy in Context & Variation

The "Around the Web" series highlights informative websites, and also targeted blog posts and news articles, relevant to the courses I teach. This semester I teach Anth 143: Biology of Human Behavior, an introductory-level course that covers the basics of evolution, behavioral biology, and the interaction of biology and culture. My hope is that these posts are useful not only for my current students, but other reasons hoping to gain background or insight into these topics.This week I have been trying to finish up two large writing projects: a new IRB and a manuscript draft. So posting has been light. I also admit to having a little trouble figuring out whether to foreground this particular Around the Web post with some of my own thoughts about this topic. I've decided to risk it.I have two main thoughts I want to offer, one on each half of the lecture I gave Tuesday; these comments will ground the links I'm sharing.Honest signaling and mate preferencesDue to time constraints, I didn't feel I could go into much detail about my unease about this particular field of research. Much of the work done on human mate preferences is quite good, especially the work that either links the preferences to fecundity/fertility (i.e., Jasienska et al 2004), or to actual reproductive success (i.e., Apicella et al 2007). What worries me when I teach this material in a large, introductory setting is that, despite any caveats I may offer about the research, students often walk away from lecture thinking that all women like strong, masculine men who are good hunters, and all men like young, feminine women with big birthing hips. This is simply not true. You can look at the assortment of who marries who and find a lot more variation, and that's because there is so much variation in mating strategy. Perhaps if someone gives you a range of faces and asks you which you prefer you choose one in line with honest signals for immune health or fertility. But do you have sex with this person or enter into a long-term relationship with this person? Not necessarily, because honest signals of health are only ONE of many factors you consider when choosing a mate. Cultural conditioning, humor, kindness, proximity, religion, political leanings... these are all issues that confound choice purely for good genes. And that's not necessarily a bad thing.In fact, an interesting article just came out that shows how some traits in preferred versus actual mates are similar, and how some are different. Definitely worth a read!Dr. Petra Boynton, sexpert, therapist, blogger, and all-around cool person, has a wonderful blog relevant to this week's topic. I'll send you over with one of my favorite posts, but check out the whole site: ten tips for successful dating.I also have to pass on an article sent to me by a student (hooray, I love when students send me stuff!). I'm very glad Davis Shannon sent me this article about body versus face preferences in men looking for one night stands. Of course, the style of the story is pretty offensive. I was also pretty appalled at the quote from the lead author. But in addition to exposing you all to a new study on this topic, it exposes you to an example of very bad science reporting. I think this is very useful to students learning to filter good information from bad.Finally, in an example of GOOD science journalism, I give you several selections from Not Exactly Rocket Science: one on male bowerbirds influencing mate choice in nestmaking, and one that is only barely related to this week's topic, on masturbating squirrels. You heard me right. Go read it, it's great.SexualityI had a rather devastating interaction with a student after class this week. This student approached me and asked me why I thought there was such a thing as homophobia. The student explained that a group of male students behind him/her were making offensive jokes during my portion of the lecture on homosexuality and were dismissive of the idea that there is a spectrum of human sexual preference that is quite normal and reflected in behaviors we see in the animal kingdom. Both the student, and I, were very upset by this, and I didn't have a particularly good answer.Oppressive behaviors of one group of people towards another are not new. But I find it especially disappointing when I hear of my own students behaving in this way, especially when I have invested so much in creating lectures with active learning components that give them space to think critically. Like I said, I have no good answers, except to have zero tolerance for such behavior if I am ever in earshot. Perhaps if more people understood that, for some people in our society, it is a huge personal risk to simply express who you love, and those of us who have a more socially-condoned sexual preference can never quite understand the toll this can take on a human being.Of course, it may be an additional condolence to find out that those individuals who are most homophobic are most likely to have hidden gay urges. No, I didn't make that up. It's SCIENCE!And for every story of teachers suspended for assigning articles on gay animals or assistant attorney generals using internet bullying tactics on gay students, there are stories of LGBT-inclusive immigration legislation or UN efforts to end laws that discriminate against homosexuals.ReferencesApicella, C., Feinberg, D., & Marlowe, F. (2007). Voice pitch predicts reproductive success in male hunter-gatherers Biology Letters, 3 (6), 682-684 DOI: 10.1098/rsbl.2007.0410Jasienska, G., Ziomkiewicz, A., Ellison, P., Lipson, S., & Thune, I. (2004). Large breasts and narrow waists indicate high reproductive potential in women Proceedings of the Royal Society B: Biological Sciences, 271 (1545), 1213-1217 DOI: 10.1098/rspb.2004.2712... Read more »

Jasienska, G., Ziomkiewicz, A., Ellison, P., Lipson, S., & Thune, I. (2004) Large breasts and narrow waists indicate high reproductive potential in women. Proceedings of the Royal Society B: Biological Sciences, 271(1545), 1213-1217. DOI: 10.1098/rspb.2004.2712  

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