A handful of fossil teeth found in Israel’s Qesem Cave, described in the American Journal of Physical Anthropology and attributed to 400,000 year old members of our own species in multiple news reports, are said to rewrite the story of human evolution. This discovery doubles the antiquity of Homo sapiens, the articles say, and identify [...]... Read more »
Hershkovitz, I., Smith, P., Sarig, R., Quam, R., Rodríguez, L., García, R., Arsuaga, J., Barkai, R., & Gopher, A. (2010) Middle pleistocene dental remains from Qesem Cave (Israel). American Journal of Physical Anthropology. DOI: 10.1002/ajpa.21446
Earlier this year, I discussed the publication of a mitochondrial DNA study from a 50,000 year old pinky bone from Denisova in Siberia. The big story there was that the mtDNA of this specimen was twice as divergent (different) from modern humans as Neandertal mtDNA. This suggested to researchers that there was this rogue human group (some [not I] might say 'species') running around Eurasia around the time of the Upper Paleolithic.
Well now they've sequenced the nuclear genome of one of a Denisova denizen. The picture painted is that a Denisova-Neandertal 'lineage' split off from that of modern humans some time in the distant past, then the Denisovans split from Neandertals some time later. Most interesting, modern-day Melanesians seem to derive about 4% of their genes from this 'archaic' Denisovan lineage, whereas this archaic genetic baggage isn't present in other modern human populations.
AMAZING! Think back to the draft of the Neandertal nuclear genome, also published earlier this year. Green and colleagues (2010) reported that the Neandertal nuclear genome revealed that Neandertals contributed up to 4% of the genomes of modern-day non-Africans. Now, the Denisova genome shows that a different and more specific group of modern humans (Melanesians) appears to uniquely share a different set of nuclear genes from an 'extinct' human group.
But if they contributed their genes to modern people, are they really extinct? Of course not! I'm admittedly not a geneticist, but I think what we're seeing here are the genetic signatures of a single, ancient structured population of modern humans. That is to say, all modern humans derive different amounts of their genes from various ancient subpopulations of 'archaic' humans (for 'archaic,' think 'people that lived a long time ago'). There was just little enough contact between these populations for them to have diverged slightly from one another, but still enough contact for them all to have contributed different parts and amounts of genes to people today.
It is weird, then, to see the ancient DNA geneticist Svante Pääbo (out of whose lab this ancient genetic work is done) say this to BBC News:"It is fascinating to see direct evidence that these archaic species did exist (alongside us) and it's only for the last few tens of thousands of years that is unique in our history that we are alone on this planet and we have no close relatives with us anymore."Why are these 'archaic species...alongside us"? The fact that these groups were mixing means that they are a single species - the ability (and propensity) to interbreed is the standard definition of 'species' used in modern biology.
So contrary to Pääbo's quote, I'd say we do have close relatives with us, it's just that modern humans are much more closely to one another related than ancient human populations were to one another. Probably there is more contact between modern human populations, beginning a few tens of thousands of years ago, because population sizes explode to the some 7 billion people we have on earth today. This greater contact means less chance for populations to diverge from one another.
The take-home: We all have multiple ancestors, from various times and places. For more comprehensive and better-informed coverage, check out John Hawks's post on the topic.ReferencesGreen, R., Krause, J., Briggs, A., Maricic, T., Stenzel, U., Kircher, M., Patterson, N., Li, H., Zhai, W., Fritz, M., Hansen, N., Durand, E., Malaspinas, A., Jensen, J., Marques-Bonet, T., Alkan, C., Prufer, K., Meyer, M., Burbano, H., Good, J., Schultz, R., Aximu-Petri, A., Butthof, A., Hober, B., Hoffner, B., Siegemund, M., Weihmann, A., Nusbaum, C., Lander, E., Russ, C., Novod, N., Affourtit, J., Egholm, M., Verna, C., Rudan, P., Brajkovic, D., Kucan, Z., Gusic, I., Doronichev, V., Golovanova, L., Lalueza-Fox, C., de la Rasilla, M., Fortea, J., Rosas, A., Schmitz, R., Johnson, P., Eichler, E., Falush, D., Birney, E., Mullikin, J., Slatkin, M., Nielsen, R., Kelso, J., Lachmann, M., Reich, D., & Paabo, S. (2010). A Draft Sequence of the Neandertal Genome Science, 328 (5979), 710-722 DOI: 10.1126/science.1188021
Reich D, Green RE, Kircher M, Krause J, Patterson N, Durand EY, Viola B, Briggs AW, Stenzel U, Johnson PL, Maricic... Read more »
Green, R., Krause, J., Briggs, A., Maricic, T., Stenzel, U., Kircher, M., Patterson, N., Li, H., Zhai, W., Fritz, M.... (2010) A Draft Sequence of the Neandertal Genome. Science, 328(5979), 710-722. DOI: 10.1126/science.1188021
Reich D, Green RE, Kircher M, Krause J, Patterson N, Durand EY, Viola B, Briggs AW, Stenzel U, Johnson PL.... (2010) Genetic history of an archaic hominin group from Denisova Cave in Siberia. Nature, 468(7327), 1053-60. PMID: 21179161
Irving Kirsch, best known for that 2008 meta-analysis allegedly showing that "Prozac doesn't work", has hit the headlines again.This time it's a paper claiming that something does work. Actually Kirsch is only a minor author on the paper by Kaptchuck et al: Placebos without Deception.In essence, they asked whether a placebo treatment - a dummy pill with no active ingredients - works even if you know that it's a placebo. Conventional wisdom would say no, because the placebo effect is driven by the patient's belief in the effectiveness of the pill.Kaptchuck et al took 80 patients with Irritable Bowel Syndrome (IBS) and recruited them into a trial of "a novel mind-body management study of IBS". Half of the patients got no treatment at all. The other half got sugar pills, after having been told, truthfully, that the pills contained no active drugs but also having been told to expect improvement in a 15 minute briefing session on the grounds thatplacebo pills, something like sugar pills, have been shown in rigorous clinical testing to produce significant mind-body self-healing processes.Guess what? The placebo group did better than the no treatment group, or at least they reported that they did (all the outcomes were subjective). The article has been much blogged about, and you should read those posts for a more detailed and in some cases skeptical examination, but really, this is entirely unsurprising and doesn't challenge the conventional wisdom about placebos.The folks in this trial believed in the possibility that the pills would make them feel better. They just wouldn't have agreed to take part otherwise. And when those people got the treatment that they expected to work, they felt better. That's just the plain old placebo effect. We already know that the placebo effect is very strong in IBS, a disease which is, at least in many cases, psychosomatic.So the only really new result here is that there are people out there who'll believe that they'll experience improvement from sugar pills, if you give them a 15 minute briefing about the "mind-body self-healing" properties of those pills. That's an interesting addition to the record of human quirkiness, but it doesn't really tell us anything new about placebos.Kaptchuk, T., Friedlander, E., Kelley, J., Sanchez, M., Kokkotou, E., Singer, J., Kowalczykowski, M., Miller, F., Kirsch, I., & Lembo, A. (2010). Placebos without Deception: A Randomized Controlled Trial in Irritable Bowel Syndrome PLoS ONE, 5 (12) DOI: 10.1371/journal.pone.0015591... Read more »
Kaptchuk, T., Friedlander, E., Kelley, J., Sanchez, M., Kokkotou, E., Singer, J., Kowalczykowski, M., Miller, F., Kirsch, I., & Lembo, A. (2010) Placebos without Deception: A Randomized Controlled Trial in Irritable Bowel Syndrome. PLoS ONE, 5(12). DOI: 10.1371/journal.pone.0015591
A look at how meme theory can explain the wide spread misquotation of it's own "inventor" Richard Dawkins.... Read more »
Dawkins, R. (1979) The selfish gene By Richard Dawkins (1977). Oxford University Press. . Journal of Human Evolution, 8(6), 647-648. DOI: 10.1016/0047-2484(79)90117-9
The best-known examples of probably cannibalism in the prehistoric Southwest all cluster in a very short period of time and in a relatively small geographic area: around AD 1150 in the area surrounding the modern town of Cortez, Colorado. Perhaps the most solidly documented of these assemblages is the one at Cowboy Wash on the [...]... Read more »
Kuckelman, K., Lightfoot, R., & Martin, D. (2002) The Bioarchaeology and Taphonomy of Violence at Castle Rock and Sand Canyon Pueblos, Southwestern Colorado. American Antiquity, 67(3), 486. DOI: 10.2307/1593823
In comments to the previous post, Graham King raises an important question: assuming that the assemblages of broken, burned, and otherwise unusually treated bones at sites like 5MT10010 at Cowboy Wash represent incidents of cannibalism, what does this mean culturally and historically? After all, cannibalism has occurred in various contexts in many societies, including our [...]... Read more »
Lambert, P., Billman, B., & Leonard, B. (2000) Explaining variability in mutilated human bone assemblages from the American Southwest: a case study from the southern piedmont of Sleeping Ute Mountain, Colorado. International Journal of Osteoarchaeology, 10(1), 49-64. DOI: 10.1002/(SICI)1099-1212(200001/02)10:13.0.CO;2-B
In their critique of the article reporting evidence for alleged cannibalism at site 5MT10100 near Cowboy Wash on the southern piedmont of Sleeping Ute Mountain, Kurt Dongoske, Debra Martin, and T. J. Ferguson challenged many of the conclusions and lines of evidence presented in the article. Among these was the evidence of consumption of human [...]... Read more »
Marlar RA, Leonard BL, Billman BR, Lambert PM, & Marlar JE. (2000) Biochemical evidence of cannibalism at a prehistoric Puebloan site in southwestern Colorado. Nature, 407(6800), 74-8. PMID: 10993075
Near the very end of his report on the excavations at Pueblo Bonito by the Hyde Expedition in the 1890s, George Pepper wrote the following: The finding of cracked and calcined bones in some of the rooms brings up the question of the eating of human flesh by the people of this pueblo. There was [...]... Read more »
Billman, B., Lambert, P., & Leonard, B. (2000) Cannibalism, Warfare, and Drought in the Mesa Verde Region during the Twelfth Century A.D. American Antiquity, 65(1), 145. DOI: 10.2307/2694812
Dongoske, K., Martin, D., & Ferguson, T. (2000) Critique of the Claim of Cannibalism at Cowboy Wash. American Antiquity, 65(1), 179. DOI: 10.2307/2694813
Lambert, P., Leonard, B., Billman, B., Marlar, R., Newman, M., & Reinhard, K. (2000) Response to Critique of the Claim of Cannibalism at Cowboy Wash. American Antiquity, 65(2), 397. DOI: 10.2307/2694066
Sand Canyon Pueblo, which I discussed in the previous post, is one of the best-known prehistoric communities in the Southwest due to the multi-year research program conducted there by Crow Canyon Archaeological Center in the 1980s and 1990s. Crow Canyon selected it for this research for a variety of reasons, including its short period of [...]... Read more »
Kenzle, S. (1997) Enclosing Walls in the Northern San Juan: Sociophysical Boundaries and Defensive Fortifications in the American Southwest. Journal of Field Archaeology, 24(2), 195. DOI: 10.2307/530471
A paper just out reports on the changing patterns of treatment for depression in the USA, over the period from 1998 to 2007.The headline news is that increased: the overall rate of people treated for some form of "depression" went from 2.37% to 2.88% per year. That's an increase of 21%, which is not trivial, but it's much less than the increase in the previous decade: it was just 0.73% in 1987.But the increase was concentrated in some groups of people.Americans over 50 accounted for the bulk of the rise. Their use went up by about 50%, while rates in younger people stayed almost steady. In '98 the peak age band was 35-49, now it's 50-64, with almost 5% of those people getting treated in any given year.Men's rates of treatment went up by over 40% while women's only increased by 10%. Women are still more likely to get treated for depression than men, though, with a ratio of 1.7 women for each 1 man. But that ratio is a lot closer than it used to be.Black people's rates increased hugely, by 120%. Rates in black people now stand at 2.2% which is close behind whites at 3.2%. Hispanics are now the least treated major ethnic group at 1.9%: in previous studies, blacks were the least treated. (There was no data on Asians or others).So the increase wasn't an across the board rise, as we saw from 1985 to 1995. Rather the '98-'07 increase was more of a "catching up" by people who've historically had low levels of treatment, closing in on the level of the historically highest group: middle-aged white women.In terms of what treatments people got, out of everyone treated for depression, 80% got some kind of drugs, and that didn't change much. But use of psychotherapy declined a bit from 54% to 43% (some people got both).What's also interesting is that the same authors reported last year that, over pretty much the same time period ('96 to '05), the number of Americans who used antidepressants in any given year sky-rocketed from 5% to 10% - that is to say, much faster than the rate of depression treatment rose! And the data are comparable, because they came from the same national MEPS surveys.In other words, the decade must have seen antidepressants increasingly being used to treat stuff other than depression. What stuff? Well, all kinds of things. SSRIs are popular in everything from anxiety and OCD to premature ejaculation. Several of the "other new" drugs, like mirtazapine and trazodone, are very good at putting you to sleep (rather too good, some users would say...)Marcus SC, & Olfson M (2010). National trends in the treatment for depression from 1998 to 2007. Archives of general psychiatry, 67 (12), 1265-73 PMID: 21135326... Read more »
Marcus SC, & Olfson M. (2010) National trends in the treatment for depression from 1998 to 2007. Archives of general psychiatry, 67(12), 1265-73. PMID: 21135326
Mitochondrial DNA and human evolution: Mitochondrial DNA from 147 people, drawn from five geographic populations have been analysed by restriction mapping. All these mitochondrial DMAs stem from one woman who is postulated to have lived ab7out 200,000 years ago, probably in Africa. All the populations examined except the African population have multiple origins, implying that [...]... Read more »
Reich, David, Green, Richard E., Kircher, Martin, Krause, Johannes, Patterson, Nick, Durand, Eric Y., Viola, Bence, Briggs, Adrian W., Stenzel, Udo, Johnson, Philip L. F.... (2010) Genetic history of an archaic hominin group from Denisova Cave in Siberia. Nature. info:/10.1038/nature09710
When I was working at Chaco and would tell visitors that I was going to graduate school for city planning, most people would remark on what a difference that sounded like. And, indeed, there are a lot of differences between my life when I was at Chaco and my life here at school in New [...]... Read more »
Bradley, B. (1993) Planning, Growth, and Functional Differentiation at a Prehistoric Pueblo: A Case Study from SW Colorado. Journal of Field Archaeology, 20(1), 23. DOI: 10.2307/530352
At the end of the last ice age modern humans were migrating out of Africa, Neanderthals roamed Europe, and new research has shown that a previously unknown population of ancient humans lived in Asia. All that remains of this mysterious group is a section of finger bone and a wisdom tooth. The group has been named the Denisovans after Denisova Cave in Siberia where the tooth and bone segment were found. A few months ago researchers completed an analysis of mitochondrial DNA from the finger bone and concluded that it had belonged to a child who lived about 40,000 years ago and was genetically different from both modern humans and Neanderthals.... Read more »
Reich, D., Green, R., Kircher, M., Krause, J., Patterson, N., Durand, E., Viola, B., Briggs, A., Stenzel, U., Johnson, P.... (2010) Genetic history of an archaic hominin group from Denisova Cave in Siberia. Nature, 468(7327), 1053-1060. DOI: 10.1038/nature09710
Habituation: a necessary method for primate research, but is it ethical from a biocentric perspective?... Read more »
Doran-Sheehy, D., Derby, A., Greer, D., & Mongo, P. (2007) Habituation of western gorillas: the process and factors that influence it. American Journal of Primatology, 69(12), 1354-1369. DOI: 10.1002/ajp.20442
by Rita Handrich in The Jury Room
I remember being fascinated by Truman Capote’s In Cold Blood. And during my maternity leave after my first child was born, I watched most of the Jeffrey Dahmer trials on CNN aware of the irony inherent in rocking my sleeping newborn while tracking the testimony of Park Dietz. So, naturally, when I saw the new [...]
Related posts:Men married to rich women are more likely to cheat
Keep your eye on this one: A Depravity Scale
New research on men: What do we know now?
... Read more »
Vicary, A., & Fraley, R. (2010) Captured by True Crime: Why Are Women Drawn to Tales of Rape, Murder, and Serial Killers?. Social Psychological and Personality Science, 1(1), 81-86. DOI: 10.1177/1948550609355486
Remember the 90s, when No Fear stuff was cool, and when people still said "cool"?Well, a new paper has brought No Fear back, by reporting on a woman who has no fear - due to brain damage. The article, The Human Amygdala and the Induction and Experience of Fear, is brought to you by a list of neuroscientists including big names such as Antonio Damasio (of Phineas Gage fame).The basic story is nice and simple. There's a woman, SM, who lacks a part of the brain called the amygdala. They found that she can't feel fear. Therefore, it's reasonable to assume that the amygdala's required for fear. But there's a bit more to it than that...The amygdala is a small nugget of the brain nestled in the medial temporal lobe. The name comes from the Greek for "almond" because apparently it looks like one, though I can't say I've noticed the resemblance myself.What does it do? Good question. There are two main schools of thought. Some think that the amygdala is responsible for the emotion of fear, while others argue that its role is much broader and that it's responsible for measuring the "salience" or importance of stimuli, which covers fear but also much else.That's where this new paper comes in, with the patient SM. She's not a new patient: she's been studied for years, and many papers have been published about her. I wonder if her acronym doesn't stand for "Scientific Motherlode"?She's one of the very few living cases of Urbach-Wiethe disease, an extremely rare genetic disorder which causes selective degeneration of the amygdala as well as other symptoms such as skin problems.Previous studies on SM mostly focussed on specific aspects of her neurological function e.g. memory, perception and so on. However there have been a few studies of her "everyday" experiences and personality. Thus we learned that:Two experienced clinical psychologists conducted "blind" interviews of SM (the psychologists were not provided any background information)... Both reached the conclusion that SM expressed a normal range of affect and emotion... However, they both noted that SM was remarkably dispassionate when relating highly emotional and traumatic life experiences... To the psychologists, SM came across as a "survivor", as being "resilient" and even "heroic".These observations were based on interviews under normal conditions; what would happen if you actually went out of your way to try and scare her? So they did.First, they took her to an exotic pet store and got her to meet various snakes and spiders. She was perfectly happy picking up the various critters and had to be prevented from getting too closely acquainted with the more dangerous ones.What's fascinating is that before she went to the store, she claimed to hate snakes and spiders! Why? Before she developed Urbach-Wiethe disease, she had a normal childhood up to about the age of 10. Presumably she used to be afraid of them, and just never updated this belief, a great example of how our own narratives about our feelings can clash with our real feelings.They subsequently confirmed that SM was fearless by taking her to a "haunted asylum" (check it out, even the website is scary) and showing her various horror movie clips, as well as through interviews with herself and her son. They also describe an incredible incident from several years ago: SM was walking home late at night when she sawA man, whom SM described as looking “drugged-out.” As she walked past the park, the man called out and motioned for her to come over. SM made her way to the park bench. As she got within arm’s reach of the man, he suddenly stood up, pulled her down to the bench by her shirt, stuck a knife to her throat, and exclaimed, “I’m going to cut you, bitch!”SM claims that she remained calm, did not panic, and did not feel afraid. In the distance she could hear the church choir singing. She looked at the man and confidently replied, “If you’re going to kill me, you’re gonna have to go through my God’s angels first.” The man suddenly let her go. SM reports “walking” back to her home. On the following day, she walked past the same park again. There were no signs of avoidance behavior and no feelings of fear.All this suggests that the amygdala has a key role in the experience of fear, as opposed to other emotions: there is no evidence to suggest that SM lacks the ability to experience happiness or sadness in the same way.So this is an interesting contribution to the debate on the role of the amygdala, although we really need someone to do equally detailed studies on other Urbach-Wiethe patients to make sure that it's not just that SM happens to be unusually brave for some other reason. What's doubly interesting, though, is that Ralph Adolphs, one of the authors, has previously argued against the view of the amygdala as a "fear center".Links: I've previously written about the psychology of horror movies and I've reviewed quite a lot of them too.Justin S. Feinstein, Ralph Adolphs, Antonio Damasio,, & and Daniel Tranel (2010). The Human Amygdala and the Induction and Experience of Fear Current Biology... Read more »
Justin S. Feinstein, Ralph Adolphs, Antonio Damasio,, & and Daniel Tranel1. (2010) The Human Amygdala and the Induction and Experience of Fear. Current Biology. info:/
The effect of the eruption of Sunset Crater Volcano on the prehistoric population of northern Arizona has long been a topic of interest to archaeologists. As I’ve mentioned recently, in the 1930s and 1940s Harold Colton of the Museum of Northern Arizona in Flagstaff came up with a theory to explain the settlement dynamics of [...]... Read more »
ORT, M., ELSON, M., ANDERSON, K., DUFFIELD, W., & SAMPLES, T. (2008) Variable effects of cinder-cone eruptions on prehistoric agrarian human populations in the American southwest. Journal of Volcanology and Geothermal Research, 176(3), 363-376. DOI: 10.1016/j.jvolgeores.2008.01.031
Wupatki is a very dry place even by the standards of the Southwest, with annual precipitation averaging about 8 inches. Human habitation in such an arid landscape is therefore highly dependent on capturing as much available moisture as possible. It appears that the prehistoric inhabitants took advantage of the volcanic ash laid down over the [...]... Read more »
This week's theme is epistemological unease in the sciences: Complaints in a number of disciplines that studies didn't really find the effects they're reporting. One reason for these worries is that many studies nowadays are never repeated. So today I'm going to consciously and rationally resist ...Read More
... Read more »
Phillips, D., Kanter, E., Bednarczyk, B., & Tastad, P. (1991) Importance of the Lay Press in the Transmission of Medical Knowledge to the Scientific Community. New England Journal of Medicine, 325(16), 1180-1183. DOI: 10.1056/NEJM199110173251620
Markey, P., & Markey, C. (2010) Changes in pornography-seeking behaviors following political elections: an examination of the challenge hypothesis. Evolution and Human Behavior, 31(6), 442-446. DOI: 10.1016/j.evolhumbehav.2010.06.004
The paper by Glenn Davis Stone and Christian Downum that I mentioned in the last post, which evaluated the archaeological record of the Wupatki area of northern Arizona in the light of Ester Boserup‘s theory of agricultural intensification, was based largely on the data from an extensive archaeological survey of Wupatki National Monument done by [...]... Read more »
Sullivan, A., & Downum, C. (1991) Aridity, activity, and volcanic ash agriculture: A study of short-term prehistoric cultural-ecological dynamics. World Archaeology, 22(3), 271-287. DOI: 10.1080/00438243.1991.9980146
Do you write about peer-reviewed research in your blog? Use ResearchBlogging.org to make it easy for your readers — and others from around the world — to find your serious posts about academic research.
If you don't have a blog, you can still use our site to learn about fascinating developments in cutting-edge research from around the world.
Research Blogging is powered by SMG Technology.
To learn more, visit seedmediagroup.com.