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  • September 2, 2010
  • 04:23 PM
  • 1,686 views

Baseball Fans Behaving Badly

by Krystal D'Costa in Anthropology in Practice

So it's done. I've accepted it. There will be no playoff entry for the Mets this year—something that was evident earlier in the year, but the motto of this team is "Ya gotta believe." So you know, I had to believe. Am I disappointed? Yes. What fan wouldn't be? Am I surprised? No. What Mets fan would be? Does it mean that I won't be there come spring anxiously awaiting the crack of the bat?

... Read more »

Brearley M. (2000) Teams: lessons from the world of sport. BMJ (Clinical research ed.), 321(7269), 1141-3. PMID: 11061741  

  • September 2, 2010
  • 12:55 PM
  • 737 views

The Science of Sexism: Primate Behavior and the Culture of Sexual Coercion

by Eric Michael Johnson in The Primate Diaries in Exile

The latest stop in the #PDEx tour is being hosted by The Intersection at Discover magazine.Despite the advances our society has made for women’s rights and sexual equality during the last century this example is just one more sign of how far we still have to go. It’s not an isolated incident. According to statistics compiled by the US Equal Employment Opportunity Commission there were 12,696 workplace sexual harassment cases filed in 2009 (which would be a fraction of the number that actually occurred) and 84% of these cases were brought by women. Businesses have gotten increasingly serious about cracking down on such abuses but last year they were still held liable to the tune of $51.5 million, the largest figure since 2001. What is going on here? Could this kind of gender inequality be an intrinsic feature of human nature that we’re stuck with or is it simply a failure to create an environment that prevents such behaviors from reoccurring?Primatologists and evolutionary biologists have taken this question seriously and have developed some surprising conclusions that could inform our approach to this issue. Unlike Randy Thornhill and Craig Palmer’s book A Natural History of Rape, a thesis that was criticized by scholars both in biology and gender studies, other evolutionary researchers have developed a much more balanced analysis. One example is from the recent edited volume Sexual Coercion in Primates and Humans by Martin Muller and Richard Wrangham. As they wrote in their introduction:[M]ales in a number of primate species appear to use force, or the threat of force, to coerce unwilling females to mate with them. . . Although the utility of this distinction has been disputed, there is no doubt that sexual coercion is a potentially important mechanism of mating bias within the broad framework of sexual conflict theory.Read the rest of the post here and stay tuned for next week's post hosted by Sex at Dawn at Psychology Today magazine.Reference:Martin N. Muller and Richard W. Wrangham (2009). Sexual Coercion in Primates and Humans: An Evolutionary Perspective on Male Aggression Against Females Harvard University Press... Read more »

Martin N. Muller and Richard W. Wrangham. (2009) Sexual Coercion in Primates and Humans: An Evolutionary Perspective on Male Aggression Against Females. Harvard University Press. info:/

  • September 2, 2010
  • 12:55 PM
  • 901 views

The Science of Sexism: Primate Behavior and the Culture of Sexual Coercion

by Eric Michael Johnson in The Primate Diaries

The latest stop in the #PDEx tour is being hosted by The Intersection at Discover magazine.Despite the advances our society has made for women’s rights and sexual equality during the last century this example is just one more sign of how far we still have to go. It’s not an isolated incident. According to statistics compiled by the US Equal Employment Opportunity Commission there were 12,696 workplace sexual harassment cases filed in 2009 (which would be a fraction of the number that actually occurred) and 84% of these cases were brought by women. Businesses have gotten increasingly serious about cracking down on such abuses but last year they were still held liable to the tune of $51.5 million, the largest figure since 2001. What is going on here? Could this kind of gender inequality be an intrinsic feature of human nature that we’re stuck with or is it simply a failure to create an environment that prevents such behaviors from reoccurring?Primatologists and evolutionary biologists have taken this question seriously and have developed some surprising conclusions that could inform our approach to this issue. Unlike Randy Thornhill and Craig Palmer’s book A Natural History of Rape, a thesis that was criticized by scholars both in biology and gender studies, other evolutionary researchers have developed a much more balanced analysis. One example is from the recent edited volume Sexual Coercion in Primates and Humans by Martin Muller and Richard Wrangham. As they wrote in their introduction:[M]ales in a number of primate species appear to use force, or the threat of force, to coerce unwilling females to mate with them. . . Although the utility of this distinction has been disputed, there is no doubt that sexual coercion is a potentially important mechanism of mating bias within the broad framework of sexual conflict theory.Read the rest of the post here and stay tuned for next week's post hosted by Sex at Dawn at Psychology Today magazine.Reference:Martin N. Muller and Richard W. Wrangham (2009). Sexual Coercion in Primates and Humans: An Evolutionary Perspective on Male Aggression Against Females Harvard University Press... Read more »

Martin N. Muller and Richard W. Wrangham. (2009) Sexual Coercion in Primates and Humans: An Evolutionary Perspective on Male Aggression Against Females. Harvard University Press. info:/

  • August 31, 2010
  • 01:47 PM
  • 991 views

Adolescent Menstrual Variation and Oral Contraceptives

by Kate Clancy in Laboratory for Evolutionary Endocrinology

This post reviews current knowledge about adolescent menstrual cycling and oral contraceptive use, making recommendations for future research.... Read more »

American Academy of Pediatrics Committee on Adolescence, American College of Obstetricians and Gynecologists Committee on Adolescent Health Care, Diaz A, Laufer MR, & Breech LL. (2006) Menstruation in girls and adolescents: using the menstrual cycle as a vital sign. Pediatrics, 118(5), 2245-50. PMID: 17079600  

Andrist LC, Arias RD, Nucatola D, Kaunitz AM, Musselman BL, Reiter S, Boulanger J, Dominguez L, & Emmert S. (2004) Women's and providers' attitudes toward menstrual suppression with extended use of oral contraceptives. Contraception, 70(5), 359-63. PMID: 15504373  

APTER, D. (1997) Development of the Hypothalamic-Pituitary-Ovarian Axis. Annals of the New York Academy of Sciences, 816(1 Adolescent Gy), 9-21. DOI: 10.1111/j.1749-6632.1997.tb52125.x  

Morimatsu, Y., Matsubara, S., Watanabe, T., Hashimoto, Y., Matsui, T., Asada, K., & Suzuki, M. (2009) Future recovery of the normal menstrual cycle in adolescent patients with secondary amenorrhea. Journal of Obstetrics and Gynaecology Research, 35(3), 545-550. DOI: 10.1111/j.1447-0756.2009.01014.x  

  • August 31, 2010
  • 01:16 AM
  • 1,029 views

The new linguistic relativism: Guy Deutscher in the NYTimes

by gregdowney in Neuroanthropology

How does language affect thought and perception? It’s a question we’ve looked at here at Neuroanthropology.net on a number of occasions, but Prof. Guy Deutscher, offers a nice general survey of the current state of play in the research over at The New York Times in ‘Does Your Language Shape How You Think?’ Posts on [...]... Read more »

  • August 30, 2010
  • 07:03 PM
  • 528 views

Human Effigy Vases

by teofilo in Gambler's House

George Pepper’s article on the excavation of Room 33 at Pueblo Bonito is fairly well-known and frequently cited, but he also published a few other articles on specific finds by the Hyde Exploring Expedition that have remained more obscure.  Among these is a chapter in a Festschrift for Franz Boas, similar to the Festschrift for [...]... Read more »

  • August 26, 2010
  • 11:22 PM
  • 1,320 views

Bad faith migration programs

by Ingrid Piller in Language on the Move

In the past couple of years, I have been a passenger in Sydney taxis driven, inter alia, by an agricultural engineer from India, a civil engineer from Somalia, a surgeon from Vietnam, an MBA graduate from Pakistan, an architect from … Continue reading →... Read more »

  • August 26, 2010
  • 05:54 PM
  • 848 views

Spices as antiseptics… maybe

by Thomas Kluyver in Thomas' Plant-Related Blog

For today, I’ve dug up a paper (I forget how) from 1998, when I was still in primary school, about why people like spicy foods, and why some cultures use more spice than others. The idea that we acquired a taste for spices to keep harmful bacteria in check isn’t implausible, but the evidence in [...]... Read more »

Billing, J., & Sherman, P. (1998) Antimicrobial Functions of Spices: Why Some Like it Hot. The Quarterly Review of Biology, 73(1), 3-49. DOI: 10.1086/420058  

  • August 26, 2010
  • 01:22 PM
  • 890 views

Why flour matters

by Julien Riel-Salvatore in A Very Remote Period Indeed

A couple of days ago, I mentioned how excavations at a Paleoindian site in Utah has revealed that the site's occupants had been milling various seeds to produce different kinds of flours. In that post, I mentioned how this discovery re-emphasized the fact that hunter-gatherers in general hunt as well as gather. In fact, outside of the highest latitudes, plant foods often account for a majority of... Read more »

Aranguren,Biancamaria, Becattini, Roberto, Mariotti Lippi, Marta, & Revedin, Anna. (2007) Grinding flour in Upper Palaeolithic Europe (25000 years bp). Antiquity, 81(314), 845-855. info:/

  • August 25, 2010
  • 01:49 PM
  • 1,112 views

Neuroscience of Murder and Aggression: Genetics

by William Yates, M.D. in Brain Posts

This is the third in a five-part series examining neuroscience aspects of homicide and aggressive behavior.  The first post examined some of the general issues in this topic and the second focused on epidemiology.  In this post I will summarize some of the genetic research.  Part four will look at neuroimaging research and part five will summarize psychopharmacologic strategies.A series of twin and adoption studies support the role for significant genetic contributions to antisocial personality and aggressive behavior.   A recent meta-analytic review estimated that 56% of the variance in antisocial personality and behavior is explained by genetic factors with 31% due to unique environmental and 11% due to shared environmental effects.  However, some studies estimate the genetic contribution to variance in antisocial behavior as high as 80%.There is some support for overlap between the clinical diagnosis of antisocial personality disorder and the diagnosis of borderline personality disorder.  Antisocial personality disorder is a male predominant disorder while borderline personality disorder is more commonly found in women.  Kendler et al in a study of the genetics and environmental contributions to personality disorder, found a genetic factor that loads on both antisocial personality disorder and borderline personality disorder. There has been much less specific attention to the genetics of murder than of the broader antisocial personality disorder phenotype.There has been a significant amount of interest in identifying biomarkers and specific genes that might account for the genetic contribution to antisocial behavior.  Gunter et al recently review the molecular biologyCandidate biomarkers and genes include:Event-related P3 electrophysiologic markersResting state EEG brain activity-beta frequency bandReduced skin conductance to stressLow childhood resting heart rateMonoamine oxidase A genotypeCatechol-O-methyltransferase (COMT) polymorphismSerotonin transporter genesAnkyrin repeat and protein kinase domain-containing protein (ANKK1)Dopamine transporter (DAT)Dopamine receptors (DRD2)Serotonin receptors 1B, 2A and 3BTryptophan hydoxylase 1 and 2Androgen receptors (AR)The issue of genetic influence in risk for violent behavior has more than a scientific perspective.  Legal scholars and practicing attorneys have been interested in this issue as a method of reducing culpability in violent offenders.  A Italian judge recently reduced the jail time for a man convicted of murder based on evidence of a genetic risk for violent behavior.Epigenetic factors are also receiving increasing attention in antisocial personality disorder.  Smoking appears to modify  the expression of gene proteins for many genes.  Methylation of MAOA is associated with nicotine and alcohol use in women.  Alcohol use also appears to influence the methylation of the dopamine transporter gene.  Prenatal, perinatal and childhood stress and abuse also may increase risk for adult antisocial behavior through and epigenetic mechanism.Gunter et al summarize the future directions of the study of the genetics of antisocial personality disorder:“Undertaking a systems approach to the biology of complex illnesses such as antisocial spectrum disorders and psychopathy, using an interdisciplinary research team, is most likely to be useful in determining how individual genetic factors impact neural networks and ultimately behavior. Various laboratory tests and imaging technologies have been employed to identify intermediate phenotypes to better understand the downstream differences that might be attributable to specific polymorphisms.”In my next post, I will explore some of the potential imaging approaches to understanding murder, aggression and antisocial personality disorder.  Advances in imaging research paired with genetic findings may provide a powerful strategy for advancing the neuroscience understanding of violent behavior.Translation Genetic Image Courtesy of the NIH and is in the Public Domain.Gunter TD, Vaughn MG, & Philibert RA (2010). Behavioral genetics in antisocial spectrum disorders and psychopathy: a review of the recent literature. Behavioral sciences & the law, 28 (2), 148-73 PMID: 20422643Kendler KS, Aggen SH, Czajkowski N, Røysamb E, Tambs K, Torgersen S, Neale MC, & Reichborn-Kjennerud T (2008). The structure of genetic and environmental risk factors for DSM-IV personality disorders: a multivariate twin study. Archives of general psychiatry, 65 (12), 1438-46 PMID: 19047531Ferguson CJ (2010). Genetic contributions to antisocial personality and behavior: a meta-analytic review from an evolutionary perspective. The Journal of social psychology, 150 (2), 160-80 PMID: 20397592Forzano F, Borry P, Cambon-Thomsen A, Hodgson SV, Tibben A, de Vries P, van El C, & Cornel M (2010). Italian appeal court: a genetic predisposition to commit murder? European journal of human genetics : EJHG, 18 (5), 519-21 PMID: 20216573... Read more »

  • August 24, 2010
  • 12:36 PM
  • 1,150 views

Harvard Confirms Scientific Micsonduct by Marc Hauser

by Greg Laden in Greg Laden's Blog

I am sad to report that it is indeed confirmed by official sources that primatologist Marc Hauser engaged in several instances of what is being termed misconduct while carrying out experiments in his lab.

Dean Michael Smith issued the following letter to members of the Harvard community today: Read the rest of this post... | Read the comments on this post...... Read more »

  • August 24, 2010
  • 01:21 AM
  • 1,500 views

Portrait of the artist as a Neanderthal

by Julien Riel-Salvatore in A Very Remote Period Indeed

In a recent paper, O. Moro Abadia and M.R. Gonzales Morales (2010) argue that an important component of the 'multiple species model' (MSM) that sees Neanderthals as having essentially 'modern' behavioral capacities and that originated in the late 90's is based not so much on new discoveries as it is on new ways of looking at the archaeological record. Specifically, they make the case that part of... Read more »

  • August 23, 2010
  • 10:12 AM
  • 1,142 views

The dog-human connection in evolution

by gregdowney in Neuroanthropology

Evolutionary theorists have long recognized that the domestication of animals represented a major change in human life, providing not just a close-at-hand food source, but also non-human muscle power and a host of other advantages. Penn State anthropologist Prof. Pat Shipman argues that animal domestication is one manifestation of a larger distinctive trait of our [...]... Read more »

Bleed, Peter. (2006) Living in the human niche. Evolutionary Anthropology: Issues, News, and Reviews, 15(1), 8-10. DOI: 10.1002/evan.20084  

Miklósi A, Kubinyi E, Topál J, Gácsi M, Virányi Z, & Csányi V. (2003) A simple reason for a big difference: wolves do not look back at humans, but dogs do. Current biology : CB, 13(9), 763-6. PMID: 12725735  

Paxton, D. (2000) A Case for a Naturalistic Perspective. Anthrozoos: A Multidisciplinary Journal of The Interactions of People , 13(1), 5-8. DOI: 10.2752/089279300786999996  

Schleidt, Wolfgang M., & Shalter, Michael D. (2003) Co-evolution of Humans and Canids: An Alternative View of Dog Domestication: Homo Homini Lupus?. Evolution and Cognition, 9(1), 57-72. info:/

Shipman, Pat. (2010) The Animal Connection and Human Evolution. Current Anthropology, 51(4), 519-538. DOI: 10.1086/653816  

  • August 20, 2010
  • 11:25 PM
  • 1,396 views

Paleolithic whodunnit: Who made the Chatelperronian?

by Julien Riel-Salvatore in A Very Remote Period Indeed

The Chatelperronian is a lithic industry that springs up for several thousand years during the transition from Middle to Upper Paleolithic industries. Its precise age is debated, but it clearly is associated with this interval. One of the reasons the Chatelperronian is the subject of so much debate is because, since the discovery of a Neanderthal in a Chatelperronian level at the site of
St. ... Read more »

  • August 20, 2010
  • 02:38 PM
  • 810 views

The Scientist and the Anarchist - Part III

by Eric Michael Johnson in The Primate Diaries

The latest stop in the #PDEx tour is being hosted by Deborah Blum at her website Speakeasy Science.When an estimated 1,400 match-girls went on strike in July, 1888 to protest for better working conditions, it started a fire that became known as New Unionism. Soon after came the London dock workers’ strike, and within twelve months the UK’s Trade Union Congress had increased its membership from 670,000 to 1,593,000. [1]For Thomas Henry Huxley and Peter Kropotkin these labor developments were interpreted very differently, and yet both saw in them important connections with their work in evolutionary biology. Huxley, who had pulled himself out of East London poverty through a combination of sheer brilliance and stubborn determination, was greatly concerned about what the workers democracy movement meant for social stability. Now the President of the Royal Academy of Sciences and a living legend in the recently established field of evolutionary biology, Huxley had come to identify with the aristocracy he’d worked so hard to be accepted by. Kropotkin, however, had rejected the silver spoon he had once been fed with as a Russian prince after coming face to face with the exploitation that made such ostentatious luxury possible. For him, the growing workers movement was the only path by which the poor could achieve any justice in a world that was undergoing radical change. Both saw in these developments a force of nature — one ominous, the other hopeful — and these conflicting visions would ultimately collide on the pages of the Nineteenth Century.Read the rest of the post here (also Part I and Part II) and stay tuned for next week's post at Anthropology in Practice.Peter Kropotkin (1902). Mutual Aide: A Factor of Evolution New York: McClure, Philips & Co.... Read more »

Peter Kropotkin. (1902) Mutual Aide: A Factor of Evolution. New York: McClure, Philips . info:/

  • August 20, 2010
  • 02:38 PM
  • 672 views

The Scientist and the Anarchist - Part III

by Eric Michael Johnson in The Primate Diaries in Exile

The latest stop in the #PDEx tour is being hosted by Deborah Blum at her website Speakeasy Science.When an estimated 1,400 match-girls went on strike in July, 1888 to protest for better working conditions, it started a fire that became known as New Unionism. Soon after came the London dock workers’ strike, and within twelve months the UK’s Trade Union Congress had increased its membership from 670,000 to 1,593,000. [1]For Thomas Henry Huxley and Peter Kropotkin these labor developments were interpreted very differently, and yet both saw in them important connections with their work in evolutionary biology. Huxley, who had pulled himself out of East London poverty through a combination of sheer brilliance and stubborn determination, was greatly concerned about what the workers democracy movement meant for social stability. Now the President of the Royal Academy of Sciences and a living legend in the recently established field of evolutionary biology, Huxley had come to identify with the aristocracy he’d worked so hard to be accepted by. Kropotkin, however, had rejected the silver spoon he had once been fed with as a Russian prince after coming face to face with the exploitation that made such ostentatious luxury possible. For him, the growing workers movement was the only path by which the poor could achieve any justice in a world that was undergoing radical change. Both saw in these developments a force of nature — one ominous, the other hopeful — and these conflicting visions would ultimately collide on the pages of the Nineteenth Century.Read the rest of the post here (also Part I and Part II) and stay tuned for next week's post at Anthropology in Practice.Peter Kropotkin (1902). Mutual Aide: A Factor of Evolution New York: McClure, Philips & Co.... Read more »

Peter Kropotkin. (1902) Mutual Aide: A Factor of Evolution. New York: McClure, Philips . info:/

  • August 20, 2010
  • 10:02 AM
  • 865 views

Schizophrenia, Genes and Environment

by Neuroskeptic in Neuroskeptic

Schizophrenia is generally thought of as the "most genetic" of all psychiatric disorders and in the past 10 years there have been heroic efforts to find the genes responsible for it, with not much success so far.A new study reminds us that there's more to it than genes alone: Social Risk or Genetic Liability for Psychosis? The authors decided to look at adopted children, because this is one of the best ways of disentangling genes and environment.If you find that the children of people with schizophrenia are at an increased risk of schizophrenia (they are), that doesn't tell you whether the risk is due to genetics, or environment, because we share both with our parents. Only in adoption is the link between genes and environment broken.Wicks et al looked at all of the kids born in Sweden and then adopted by another Swedish family, over several decades (births 1955-1984). To make sure genes and environment were independent, they excluded those who were adopted by their own relatives (i.e. grandparents), and those lived with their biological parents between the ages of 1 and 15. This is the kind of study you can only do in Scandinavia, because only those countries have accessible national records of adoptions and mental illness...What happened? Here's a little graph I whipped up:Brighter colors are adoptees at "genetic risk", defined as those with at least one biological parent who was hospitalized for a psychotic illness (including schizophrenia but also bipolar disorder.) The outcome measure was being hospitalized for a non-affective psychosis, meaning schizophrenia or similar conditions but not bipolar.As you can see, rates are much higher in those with a genetic risk, but were also higher in those adopted into a less favorable environment. Parental unemployment was worst, followed by single parenthood, which was also quite bad. Living in an apartment as opposed to a house, however, had only a tiny effect.Genetic and environmental risk also interacted. If a biological parent was mentally ill and your adopted parents were unemployed, that was really bad news.But hang on. Adoption studies have been criticized because children don't get adopted at random (there's a story behind every adoption, and it's rarely a happy one), and also adopting families are not picked at random - you're only allowed to adopt if you can convince the authorities that you're going to be good parents.So they also looked at the non-adopted population, i.e. everyone else in Sweden, over the same time period. The results were surprisingly similar. The hazard ratio (increased risk) in those with parental mental illness, but no adverse circumstances, was 4.5, the same as in the adoption study, 4.7.For environment, the ratio was 1.5 for unemployment, and slightly lower for the other two. This is a bit less than in the adoption study (2.0 for unemployment). And the two risks interacted, but much less than they did in the adoption sample.However, one big difference was that the total lifetime rate of illness was 1.8% in the adoptees and just 0.8% in the nonadoptees, despite much higher rates of unemployment etc. in the latter. Unfortunately, the authors don't discuss this odd result. It could be that adopted children have a higher risk of psychosis for whatever reason. But it could also be an artefact: rates of adoption massively declined between 1955 and 1984, so most of the adoptees were born earlier, i.e. they're older on average. That gives them more time in which to become ill.A few more random thoughts:This was Sweden. Sweden is very rich and compared to most other rich countries also very egalitarian with extremely high taxes and welfare spending. In other words, no-one in Sweden is really poor. So the effects of environment might be bigger in other countries.On the other hand this study may overestimate the risk due to environment, because it looked at hospitalizations, not illness per se. Supposing that poorer people are more likely to get hospitalized, this could mean that the true effect of environment on illness is lower than it appears.The outcome measure was hospitalization for "non-affective psychosis". Only 40% of this was diagnosed as "schizophrenia". The rest will have been some kind of similar illness which didn't meet the full criteria for schizophrenia (which are quite narrow, in particular, they require 6 months of symptoms).Parental bipolar disorder was counted as a family history. This does make sense because we know that bipolar disorder and schizophrenia often occur in the same families (and indeed they can be hard to tell apart, many people are diagnosed with both at different times.)Overall, though, this is a solid study and confirms that genes and environment are both relevant to psychosis. Unfortunately, almost all of the research money at the moment goes on genes, with studying environmental factors being unfashionable.Wicks S, Hjern A, & Dalman C (2010). Social Risk or Genetic Liability for Psychosis? A Study of Children Born in Sweden and Reared by Adoptive Parents. The American journal of psychiatry PMID: 20686186... Read more »

  • August 19, 2010
  • 04:32 PM
  • 522 views

About Those Chaco Burials

by teofilo in Gambler's House

In discussing a recent paper using stable-isotope techniques to evaluate subsistence in the Southwest during the Basketmaker period, I mentioned that one of the control samples used for contextual comparisons of the Basketmaker results came from Chaco Canyon great house burials.  I don’t know how on earth the Utah-based researchers managed to get permission to [...]... Read more »

  • August 19, 2010
  • 01:29 PM
  • 580 views

Sacrifice on the Serengeti: Life History, Genetic Relatedness, and the Evolution of Menopause

by Eric Michael Johnson in The Primate Diaries

The latest stop in the #PDEx tour is being hosted by Dr. Carin Bondar at her website CarinBondar.com.Imagine you’re on the Serengeti Plateau and your children are hungry. For miles in every direction there’s nothing but dry scrub grass with the occasional flat-topped acacia tree marking the landscape. Your oldest has found a spot to dig for tubers but he and your daughter aren’t strong enough to scrape away the hard, baked earth by themselves. Your husband is tracking a wounded gazelle and could be gone for days. Meanwhile, the infant slung to your hip has started screaming and the distinctive sound triggers a release of oxytocin that causes your breasts to swell and leak. You have to feed her but you can’t do that and make sure your other children get enough to eat. There’s a very real chance that some of them will be too weak to survive the next time fever breaks out unless you can get help. You simply can’t be everywhere at once. It’s a desperate feeling but these are the daily realities among the East African Hadza. If it wasn’t for your mother, already kneeled on the ground and using a stick to claw through several layers of tough sediment, it might have been your reality as well. While your baby makes soft cooing sounds as she suckles you can only feel grateful that you were the youngest child in your family, or else your mother might well have had an infant of her own to care for.This scenario provides the backdrop behind a perplexing question about human evolution: the advent of female reproductive senescence. Between the ages of 45-50 all women undergo physiological changes commonly known as menopause that result in the cessation of ovarian function. Since most women live longer than 50, even in preindustrial and hunter-gatherer societies, this raises a profound evolutionary question: Why would a species “choose” to forego one-third (and sometimes as much as one-half) of their reproductive potential?Read the rest of the post here and stay tuned for the conclusion of The Scientist and the Anarchist tomorrow (see here for Part I and Part II) hosted by Deborah Blum at Speakeasy Science.References:Hawkes, K. (2010). How grandmother effects plus individual variation in frailty shape fertility and mortality: Guidance from human-chimpanzee comparisons Proceedings of the National Academy of Sciences, 107 (Supp. 2), 8977-8984 DOI: 10.1073/pnas.0914627107Fox, M., Sear, R., Beise, J., Ragsdale, G., Voland, E., & Knapp, L. (2010). Grandma plays favourites: X-chromosome relatedness and sex-specific childhood mortality Proceedings of the Royal Society B: Biological Sciences, 277 (1681), 567-573 DOI: 10.1098/rspb.2009.1660... Read more »

Fox, M., Sear, R., Beise, J., Ragsdale, G., Voland, E., & Knapp, L. (2009) Grandma plays favourites: X-chromosome relatedness and sex-specific childhood mortality. Proceedings of the Royal Society B: Biological Sciences, 277(1681), 567-573. DOI: 10.1098/rspb.2009.1660  

  • August 19, 2010
  • 01:29 PM
  • 566 views

Sacrifice on the Serengeti: Life History, Genetic Relatedness, and the Evolution of Menopause

by Eric Michael Johnson in The Primate Diaries in Exile

The latest stop in the #PDEx tour is being hosted by Dr. Carin Bondar at her website CarinBondar.com.Imagine you’re on the Serengeti Plateau and your children are hungry. For miles in every direction there’s nothing but dry scrub grass with the occasional flat-topped acacia tree marking the landscape. Your oldest has found a spot to dig for tubers but he and your daughter aren’t strong enough to scrape away the hard, baked earth by themselves. Your husband is tracking a wounded gazelle and could be gone for days. Meanwhile, the infant slung to your hip has started screaming and the distinctive sound triggers a release of oxytocin that causes your breasts to swell and leak. You have to feed her but you can’t do that and make sure your other children get enough to eat. There’s a very real chance that some of them will be too weak to survive the next time fever breaks out unless you can get help. You simply can’t be everywhere at once. It’s a desperate feeling but these are the daily realities among the East African Hadza. If it wasn’t for your mother, already kneeled on the ground and using a stick to claw through several layers of tough sediment, it might have been your reality as well. While your baby makes soft cooing sounds as she suckles you can only feel grateful that you were the youngest child in your family, or else your mother might well have had an infant of her own to care for.This scenario provides the backdrop behind a perplexing question about human evolution: the advent of female reproductive senescence. Between the ages of 45-50 all women undergo physiological changes commonly known as menopause that result in the cessation of ovarian function. Since most women live longer than 50, even in preindustrial and hunter-gatherer societies, this raises a profound evolutionary question: Why would a species “choose” to forego one-third (and sometimes as much as one-half) of their reproductive potential?Read the rest of the post here and stay tuned for the conclusion of The Scientist and the Anarchist tomorrow (see here for Part I and Part II) hosted by Deborah Blum at Speakeasy Science.References:Hawkes, K. (2010). How grandmother effects plus individual variation in frailty shape fertility and mortality: Guidance from human-chimpanzee comparisons Proceedings of the National Academy of Sciences, 107 (Supp. 2), 8977-8984 DOI: 10.1073/pnas.0914627107Fox, M., Sear, R., Beise, J., Ragsdale, G., Voland, E., & Knapp, L. (2010). Grandma plays favourites: X-chromosome relatedness and sex-specific childhood mortality Proceedings of the Royal Society B: Biological Sciences, 277 (1681), 567-573 DOI: 10.1098/rspb.2009.1660... Read more »

Fox, M., Sear, R., Beise, J., Ragsdale, G., Voland, E., & Knapp, L. (2009) Grandma plays favourites: X-chromosome relatedness and sex-specific childhood mortality. Proceedings of the Royal Society B: Biological Sciences, 277(1681), 567-573. DOI: 10.1098/rspb.2009.1660  

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