Ember & Ember show that the degree of sonority in a language is related to the frequency of extramarital sex in its community. Could this be linked to why smaller communities have a smaller phoneme inventory?... Read more »
EMBER, C., & EMBER, M. (2007) Climate, Econiche, and Sexuality: Influences on Sonority in Language. American Anthropologist, 109(1), 180-185. DOI: 10.1525/aa.2007.109.1.180
MUNROE, R., & FOUGHT, J. (2007) Response to Ember and Ember's “Climate, Econiche, and Sexuality: Influences on Sonority in Language”. American Anthropologist, 109(4), 784-785. DOI: 10.1525/aa.2007.109.4.784
We’ve written a fair bit about the System of Rice Intensification, or SRI, and our most recent little piece sparked what passes for a vociferous debate over at Facebook (which of course I cannot now link to). As I recall it all seemed to hinge on whether there was one SRI or several different systems, [...]... Read more »
Shepherd, C., & McWilliam, A. (2011) Ethnography, Agency, and Materiality: Anthropological * Perspectives on Rice Development in East Timor. East Asian Science, Technology and Society, 5(2), 189-215. DOI: 10.1215/18752160-1262876
In Ars Poetica (“The Art of Poetry”), the great Roman lyricist Horace counsels against using gods to resolve thorny plots. The deus ex machina is simply too tidy and unbelievable. When gods swoop in to save the day, the mundane becomes sacred. Metaphysics to the rescue.
I was reminded of Horace’s enduring wisdom by two recent [...]... Read more »
Delton AW, Krasnow MM, Cosmides L, & Tooby J. (2011) Evolution of direct reciprocity under uncertainty can explain human generosity in one-shot encounters. Proceedings of the National Academy of Sciences of the United States of America. PMID: 21788489
Mathew S, & Boyd R. (2011) Punishment sustains large-scale cooperation in prestate warfare. Proceedings of the National Academy of Sciences of the United States of America, 108(28), 11375-80. PMID: 21670285
This new article has gained substantial attention on the interwebs, and who can blame us? After all, knights, shining armor, it's what lots of people like to pretend to be (or pretend to be rescued by, goes both ways). Picture it if you would: a damsel in distress, inches from death in the maw of [...]... Read more »
Askew, G., Formenti, F., & Minetti, A. (2011) Limitations imposed by wearing armour on Medieval soldiers' locomotor performance. Proceedings of the Royal Society B: Biological Sciences. DOI: 10.1098/rspb.2011.0816
The Three Stooges was the source of an ongoing controversy between my parents. My dad introduced my brother and I to their antics and would often laugh along with us as we imitated their physical hijinks in front of the TV. But, for my mom, the Stooges’ fake violence and prat falls were simply ridiculous [...]
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Van Leeuwen, E., Zimmermann, E., & Ross, M. (2010) Responding to inequities: gorillas try to maintain their competitive advantage during play fights. Biology Letters. DOI: 10.1098/rsbl.2010.0482
According to the BBC, a new study has found that northern peoples have bigger eyes - and bigger brains.Actually, the paper in question talked about eyes but didn't make much of the brain finding, which is confined to the Supplement. Nonetheless, they did find an effect on brain size too. Peoples living further from the equator have larger eye sockets and also larger total cranial capacity (brain volume), apparantly. The authors include Robin Dunbar of "Dunbar's Number" fame.Their idea is that humans evolved larger eyes because further from the equator, there's on average less light, so you need bigger eyes to collect more light and see well.They looked at 19th century skulls stored in museum collections, and measured the size of the eye sockets (orbits). They did this by filling them with a bunch of little glass balls and counting how many balls fit. They had a total of 73 "healthy adult" skulls from 12 different places, ranging from Scandinavia to Kenya.Latitude essentially meant northern-ness because only one population (Australian Aborigines) were from far south of the equator.Total brain size also increased with latitude, but eye size increased even faster, so the eye:brain ratio increased. They don't really discuss the brain size finding, except to suggest that it might be accounted for by increased visual cortex (though there's no direct evidence of that), but here it is, showing latitude vs. cranial capacity in ml.The idea that northern peoples are brainier unfortunately has a long history. For example, it's been suggested that the coldness of northern climes meant that life was harder, so people evolved to be smarter to survive.The heat of the Sahara was easy living compared to the deadly horrors of an English winter, in other words. Hmm.The idea that higher latitudes are darker, so you'd need bigger eyes, and then a bigger brain (at least the visual parts of the brain) to process what you see, is certainly more plausible than that theory. However, the data in this paper seem pretty scanty.Measuring skulls by filling them with little balls was cutting edge neuroscience in the 19th century. However, nowadays, we have MRI scanners. Although usually intended to image the brain, many MRI scans of the head also give an excellent image of the skull and eyes. Millions of people of all races get MRI scans every year.Nowadays, people have medical records, so we can tell exactly how healthy people are. The people who became these skulls in a museum were said to be healthy, but how healthy a 19th century Indian or Kenyan could hope to be, by modern standards, I'm not sure. Certainly there's an excellent chance that they were malnourished and I suspect this would make your eyes and skull smaller.Pearce, E., & Dunbar, R. (2011). Latitudinal variation in light levels drives human visual system size Biology Letters DOI: 10.1098/rsbl.2011.0570... Read more »
Pearce, E., & Dunbar, R. (2011) Latitudinal variation in light levels drives human visual system size. Biology Letters. DOI: 10.1098/rsbl.2011.0570
Even if you stay free of Alzheimer's disease, the normal aging process is fairly destructive to your brain. Neurons disappear, connections lose their strength, protein gunk builds up, and the whole brain shrinks. Areas controlling learning and memory are among the hardest hit. A new study claims that our crumbling brains aren't just a fact of normal aging. Instead, they may be unique in the animal kingdom, the result of an evolutionary bargain our species has struck.Chet Sherwood at George Washington University led the study, which put humans and captive chimpanzees of various ages through MRI scanners. The humans ranged from ages 22 to 88. Chimps were between 10 and 45 years old, because 45 years is about as long as chimps can live in the wild (more on that in a moment).In humans, the researchers found a pattern of decreasing brain volume throughout life that accelerated into old age. That pattern was missing in chimpanzees, whose brains seemed to maintain a consistent size.Chimpanzees were used because they're our closest living relatives; we've been apart for only about 6 million years of evolution. The authors reason that because chimps' brains don't shrink as they age, our own brain degeneration must be a product of our recent evolution. We've developed brains that are big and energy-hungry, and to judge from our global population size, throwing our resources into our noggins seems to have been a good evolutionary strategy.Since splitting from our ape relatives, we've also evolved longer life spans. Women, in particular, are a curiosity because they can live decades past their fertile years. Evolutionary biologists have hypothesized that keeping infertile elderly women around is no accident, because these grandmothers can bolster the success of their own genes by helping to take care of their grandchildren. The authors of the chimp study suggest that these helpful grandmothers are to blame for our degenerating brains: we've evolved long lifespans and brains that can't quite keep up.The grandmother hypothesis, though, is hard to prove. And though 45 is elderly for a chimpanzee in the wild, the authors acknowledge that chimps under medical care in captivity can live into their 60s. Is a human today who lives into her 80s, thanks to medical care and disease prevention, comparable to a chimp in the wild? Or is a human "in the wild" better represented by someone in a southern African country with a life expectancy in the 30s or 40s?If this study included chimpanzees at the true upper end of their age potential, it might provide more insight. The authors acknowledge that some previous studies have shown different results; for example, a study of brain mass that included chimpanzees up to age 59 did find some shrinkage with age.The authors assume our damaging brain decline is a byproduct of evolution, but don't ask whether it might come from extending our life spans even further than evolution intended. Some perspective might come from studying another animal that no longer lives "in the wild": domestic dogs. Wolves live six to eight years in the wild, but many kinds of pet dogs can live for twice that long.Even though they're not close to us in evolutionary terms, dogs age much like humans do. Their brains shrink in old age, especially in the prefrontal cortex and the hippocampus--the same areas that are particularly vulnerable in humans. Dogs develop cognitive problems and behavioral changes. Their brains even accumulate deposits of amyloid-beta, the protein gunk that appears in humans and is linked to Alzheimer's disease. Maybe our aging brains are not only the result of our exceptional smarts, then, but also of our domestication.Sherwood, C., Gordon, A., Allen, J., Phillips, K., Erwin, J., Hof, P., & Hopkins, W. (2011). Aging of the cerebral cortex differs between humans and chimpanzees Proceedings of the National Academy of Sciences DOI: 10.1073/pnas.1016709108... Read more »
Sherwood, C., Gordon, A., Allen, J., Phillips, K., Erwin, J., Hof, P., & Hopkins, W. (2011) Aging of the cerebral cortex differs between humans and chimpanzees. Proceedings of the National Academy of Sciences. DOI: 10.1073/pnas.1016709108
Daniel Tammet's second book, Embracing The Wide Sky (2009), is enthralling. In his own words, the book is "a personal and scientific exploration of how the brain works". To my great delight, I discovered that it even indirectly features my work on Siwu ideophones. In this post I set out a few things we learn from his invention of a new Siwu ideophone, pambalaa.
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Tammet, Daniel. (2009) Embracing the Wide Sky: A Tour Across the Horizons of the Mind. New York: Free Press. info:/
With Julia spending the summer and most of the fall in The Republic of Georgia, I've been thinking about various political and historical aspects of that country, and one of the things that is claimed to be true is that wine was first invented there. Recently, someone asked me (always ask the archaeologist esoteric stuff like this) where wine was first invented. And, recently, we scored some Concord Grapes, which are native to North America (presumably thanks to some bird a long time ago) as opposed to most grapes, and which provide the roots for most (nearly all?) wine grape stock. And, a paper on the genetics of wine came out recently and has been staring at me for a few weeks now. All these things together made me want to update my current knowledge of the origin of wine. Read the rest of this post... | Read the comments on this post...... Read more »
Myles, Sean, Boyko, Adam, Owens, Christopher, Brown, Patrick, Grassi, Fabrizio, Aradhya, Mallikarjuna, Prins, Bernard, Reynolds,Andy, Chia, Jer-Ming, Ware, Doreen.... (2011) Genetic structure and domestication history of the grape. PNAS. info:/
Butter Milk Creek is a Texas archaeological site and an archaeological complex located rather symbolically a couple of hundred miles downstream from the famous Clovis site in New Mexico. It is the most recently reported alleged manifestation of a "pre-Clovis" archaeological presence. The most important thing about this site is probably this: It is well dated (though the dates need to be independently verified or otherwise run through the gauntlet of criticism dates of important sites are always subjected to) and there are a lot of artifacts at the site. The importance of the number of artifacts is two-fold: It means that the site is unambiguously evidence of human activities and not of the activities of, say, a ground squirrel burrow into which a random artifact from a later time fell, and it means that researchers will be able to say something interesting about the lithic (stone tool) technology represented there.
In order to understand why a "pre-Clovis" site is interesting, one needs to understand the peculiar nature of American archaeology and its conceptions of prehistory. Read the rest of this post... | Read the comments on this post...... Read more »
Waters, M., Forman, S., Jennings, T., Nordt, L., Driese, S., Feinberg, J., Keene, J., Halligan, J., Lindquist, A., Pierson, J.... (2011) The Buttermilk Creek Complex and the Origins of Clovis at the Debra L. Friedkin Site, Texas. Science, 331(6024), 1599-1603. DOI: 10.1126/science.1201855
There’s a sign hanging in my local deli that offers customers some tips on what to expect in terms of quality and service. It reads: Your order: Can be fast and good, but it won’t be cheap. Can be fast and cheap, but it won’t be good. Can be good and cheap, but it won’t [...]
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Laudan, R. (2001) A Plea for Culinary Modernism: Why We Should Love New, Fast, Processed Food. Gastronomica, 1(1), 36-44. DOI: 10.1525/gfc.2001.1.1.36
In 2006, archaeologists exhumed the remains of the legendary 18th century castrato, Carlo Maria Broschi, better known as Farinelli. As a boy, Farinelli showed talent as an opera singer and, when their father died young, his elder brother Riccardo made the decision to have Farinelli castrated, an illegal operation at the time, in order to preserve his voice. Farinelli became quite famous by the 1720s and sang daily until his death at the age of 78. An analysis of the bones has just been published in the Journal of Anatomy by Belcastro, Fornaciari, and Mariotti, with the most salient finding being that Farinelli's castration led to hormonal changes that likely caused him to develop internal frontal hyperostosis (or hyperostosis frontalis interna, depending on what side of the Atlantic you're from), a thickening of the frontal bone in the cranial vault that is found almost exclusively in postmenopausal women.
Farinelli's bones, circled
(credit: Belcastro et al., Fig. 1)
Crush fraction of an L vert
(credit: Belcastro et al., Fig. 5)
Farinelli's bones were eventually moved to the grave of his great-niece, Maria Carlotta Pisani, and placed at her feet (see photo). The bones were unfortunately not at all well-preserved. Belcastro and colleagues could only estimate sex based on the narrow sciatic notch and the absence of a preauricular sulcus. In terms of age, they found evidence of fused cranial sutures, porosity of the auricular surface, trabecular thinning, degenerative changes in the vertebrae, and a compression fracture of one of the lumbar vertebrae, all pointing to an advanced age for this individual. Interestingly, they noticed incomplete obliteration of the epiphyseal lines on the medial border of the left scapula and the left iliac crest. While epiphyseal lines can persist into adulthood, they almost never persist past about 35 years old. Based on the length of the right ulna, they estimate his stature at 6'3". Of the 14 teeth that could be properly examined, there was evidence of caries in two, leading them to conclude he had good oral hygiene.
Thickening of Farinelli's frontal bone
(credit: Belcastro et al., Fig. 8)
When Belcastro and colleagues reconstructed some of the cranial fragments, they discovered extreme thickening of the vault (see photo), up to 21mm at the thickest. As the area around the sagittal sulcus was unaffected, the authors conclude that the thickening is internal frontal hyperostosis rather than Paget's, acromegaly, fibrous dysplasia, or meningioma. The etiology of IFH is not actually very clear, but the fact that it's found almost exclusively in post-menopausal women and men with hormonal disturbances (e.g., Klinefelter's syndrome) points to a problem with the body's hormonal balance. Belcastro and colleagues succinctly review the clinical literature on IFH in men and conclude that Farinelli's IFH is most likely related to his castration. Interestingly, castration can also explain his height (due to delayed epiphyseal fusion) and the finding of unfused epiphyses in his skeleton.
It's no secret that I am not a fan of digging up famous dead Italians, but in this case, Belcastro and colleagues have published the only osteological analysis of a castrato or eunuch. Granted, the identification of this skeleton with Farinelli is not 100% clear because of the condition of the remains, but it's reasonable to assume that they did indeed find the man.
Portrait of Farinelli
(credit: Wikimedia commons)
The question remains, though, what effect IFH would have had on Farinelli's life, or on the lives of the numerous women who are also affected by this condition? The clinical literature suggests that IFH is basically asymptomatic - because the disease has such a slow progression, over the span of decades, even the most severe cases of cranial thickening are assumed to pose no problem for the individual, whose brain can compensate little by little to the change in skull shape. A short New Scientist piece, though, quotes Israel Hershkovitz as claiming that IFH is linked to "behavioral disorders, headaches, and neurological diseases like Alzheimer's." Because of this quote, New Scientist ran with the headline "Lack of testes gave castrato superstar headaches." Belcastro and colleagues, of course, didn't say anything about headaches, but apparently New Scientist thinks that discovering osteological evidence of a hormonal imbalance in the skeleton of a castrato isn't interesting enough for their readers.
I'll have to look into the claim that IFH does produce symptoms like headaches, though, as I'm quite interested in the pathology. IFH is often not noticed in a bioarchaeological population unless the skulls are broken in just the right places. Bioarchaeologists don't tend to have enough money to xray or CT hundreds of individuals as we collect data, so I suspect that we miss quite a few ancient cases of this condition. I looked at a couple hundred skeletons from Imperial Rome and found one case of IFH (below), and I looked at a couple dozen skeletons from Gabii and found another case.
IFH in an Imperial Roman woman in her early 40s
(credit: Killgrove 2010)
A project that I would like to undertake in the future deals with understanding the lives of post-menopausal women in Rome. These women were often seen as second-class citizens, even more so than women in general, because they were past their reproductive prime. Looking at the prevalence of IFH w... Read more »
MG Belcastro, G Fornaciari, & V Mariotti. (2011) Hyperostosis frontalis interna (HFI) and castration: the case of the famous singer Farinelli (1705-1782). Journal of Anatomy. PMID: 21740437
Today's Daily Mail and Wednesday's USA Today have short articles summarizing a recently-published study by Shane McLeod, called "Warriors and women: the sex ratio of Norse migrants to eastern England up to 900 AD." It's an interesting little piece, in which McLeod takes issue with the assumption that the Viking "warriors" were only men, an assumption that has been based primarily on grave goods and our own preconceptions about men and women in antiquity. Previous research into Viking graves has resulted in estimates of 80-85% males, and this has clearly affected how scholars viewed the Vikings and their contributions, writes McLeod. It's hard to tease out McLeod's data in this paper, which was written for the journal Early Medieval Europe and is historical in bent, but he seems to have limited his sample to those burials from which sex could be estimated osteologically and which chemical analysis revealed were almost certainly Viking immigrants (Budd et al. 2003). McLeod concludes:
The reappraisal of the burial evidence for Norse migrants in eastern England up to 900 has provided a different perception of the possible numbers of Norse women involved in the early settlement period. Based on jewellery finds and the notion of an undocumented secondary migration, it has been suspected by some scholars that substantial numbers of Norse women were involved in the settlements. But there has previously been little substantive evidence to validate this claim, leading other scholars to suggest that the Norse settlers were overwhelmingly male. Although the results presented here cannot be used to determine the number of female settlers, they do suggest that the ratio of females to males may have been somewhere between a third to roughly equal. Furthermore, there is osteologically sexed burial evidence of Norse women in England during the earliest campaigning period of the great army of 865. It is possible that with further advances in science more evidence is likely to appear, providing a larger sample to work with, and enabling similar reappraisals of burial evidence from other areas of Norse settlement. The present results suggest new ways of understanding Norse migration and acculturation in late ninth-century England.
Reconstruction of a Viking boat (credit)
While I like the fact that McLeod tackles old assumptions in this short article, there are a couple worrying aspects. The part about "acculturation" is not well laid out, as McLeod and others are assuming that Viking men would have acculturated to local habits more easily with Anglo-Saxon wives, and that having Viking wives may make researchers reevaluate acculturation. Attempting to figure out biocultural relationships between two groups of people who hadn't previously met is quite difficult. Witness, as one example, the centuries of literature on "Romanization" in the provinces in the Roman Empire. Only within the last decade has there been a backlash from scholars against a far too facile understanding of the bi-directional process of culture sharing.
The other worrying part is that McLeod uses terms like "wives" and "widowed" in his paper, which makes the assumption (and conveys the idea) that the Vikings were married in the contemporary sense. I could point to the literature on the Roman army as a cautionary tale here. It had been assumed for centuries that the Roman army was only composed of men and that women and children, if they were present, lived outside the fort. Finally, new evidence is being found and old evidence is being reevaluated, suggesting previous scholars were simply seeing what they wanted to see: Roman soldiers weren't married, and women certainly didn't live in the fort, in spite of the massive amount of evidence to the contrary. My point is, without further investigation, we don't know if the Viking men and women found were spouses - Could they have been siblings or other kin? How about slaves? Could the women have been warriors themselves? I don't know anything about Viking relationships, though, so perhaps the conclusion that the Viking women were wives is valid. McLeod does note that the sample may be biased, and there may not have been a 50/50 ratio of males to females, but the Daily Mail article picked up on this concept of "wives" and pairs of Vikings.
Overall, though, a nice article. It highlights how far we've come in archaeological and historical scholarship on issues of sex, gender, and cultural biases, but also shows how far we still need to go. It demonstrates that bioarchaeological research - even quite technical papers - can be used by social scientists and humanists to support arguments and conclusions. And it lets me mention the always-brilliant work of Budd, Chenery, Montgomery, and Evans, who do amazing things with isotopes in England.
(For more, see Katy Meyers' post at Bones Don't Lie. I'm woefully behind on my news feed at the moment and just noticed her summary of the article.)
P. Budd, C. Chenery, J. Montgomery, J. Evans, & D. Powlesland (2003). Anglo-Saxon Residential Mobility at West Heslerton, North Yorkshire, UK From Combined O- and Sr-Isotope Analysis Plasma Source Mass Spectrometry: Applications and Emerging Technologies, 195-208.
S. McLeod (2011). Warriors and women: the sex ratio of Norse migrants to eastern England up to 900 AD Early Medieval Europe, 19 (3), 332-353.... Read more »
S. McLeod. (2011) Warriors and women: the sex ratio of Norse migrants to eastern England up to 900 AD. Early Medieval Europe, 19(3), 332-353. info:/10.1111/j.1468-0254.2011.00323.x
Studying ancient microbes requires creativity. Contamination and preservation are the primary problems, dealing with limited and degraded tissues. We don’t find corpses in permafrost every day! Most of the time tissue is confined to bones and mummies kept in a wide variety of environments. This post will review some of the major tools I have [...]... Read more »
Drancourt, M., & Raoult, D. (2005) Palaeomicrobiology: current issues and perspectives. Nature Reviews Microbiology, 3(1), 23-35. DOI: 10.1038/nrmicro1063
A recently published article in the Journal of Quaternary Science by Strasser and colleagues suggests new dates for stone tools discovered on the island of Crete. Namely, the artifacts are associated with geological strata that date to the late Middle Pleistocene or early Late Pleistocene, meaning a terminus ante quem of 125,000 years ago.
An archaeological survey in the Plakias area of Crete between 2008-09 uncovered nine sites and over 400 artifacts. The stone tools discovered were Acheulean in type, with bifaces, cleavers, cores, and flake tools made out of quartz, and are similar to tools found elsewhere on the Greek mainland:
Bifaces from Crete. (Credit: Strasser and colleagues 2011, Figure 2)
Through an impressive array of geological and chemical analyses (which I don't have time to delve into at the moment), the authors conclude that these tools represent the earliest known occupation of Crete, placing it at around 125,000 years ago. This date contradicts the assumption that Crete was not occupied until the advent of anatomically modern humans. According to Strasser and colleagues:
The relatively large numbers of Palaeolithic artefacts found in this one small region (∼30 km2) – the first to be searched systematically for these materials and to be subjected to geological and chronostratigraphical analyses – suggest that a hominin presence on Crete may have been widespread and perhaps long lasting. This would indicate that early hominins were able to reach Crete from Greece, Turkey, the Near East or Africa by crossing open bodies of water. Only hominins with the technical means and cognitive skills required to build boats and to navigate among the islands would have been able to establish an enduring presence on the large and difficult-to-access island of Crete.This is a really interesting finding, and I hope it's only a matter of time until archaeologists start finding hominin fossils on Crete.
T. Strasser, E. Panagopoulou, C. Runnels, P. Murray, N. Thompson, P. Karkanas, F. McCoy, & K. Wegmann (2010). Stone Age seafaring in the Mediterranean: Evidence from the Plakias region for Lower Palaeolithic and Mesolithic habitation of Crete Hesperia, 79 (2), 145-190.
T. Strasser, C. Runnels, K. Wegmann, E. Panagopoulou, F. McCoy, C. Digregorio, P. Karkanas, & N. Thompson (2011). Dating Palaeolithic sites in southwestern Crete, Greece Journal of Quaternary Science, 26 (5), 553-560. DOI: 10.1002/jqs.1482.... Read more »
T. Strasser, E. Panagopoulou, C. Runnels, P. Murray, N. Thompson, P. Karkanas, F. McCoy, & K. Wegmann. (2010) Stone Age seafaring in the Mediterranean: Evidence from the Plakias region for Lower Palaeolithic and Mesolithic habitation of Crete. Hesperia, 79(2), 145-190. info:/
T. Strasser, C. Runnels, K. Wegmann, E. Panagopoulou, F. McCoy, C. Digregorio, P. Karkanas, & N. Thompson. (2011) Dating Palaeolithic sites in southwestern Crete, Greece. Journal of Quaternary Science, 26(5), 553-560. info:/10.1002/jqs.1482
For Dr. Mick Wilkinson barefoot running has got to have sole. More than just moving joints cuz their designed to move is to consider the surface of the foot, and what it's designed to do, and how that actually also needs to inform movement - and how movement is changed because of this feedback.... Read more »
LIEBENBERG, L. (2008) The relevance of persistence hunting to human evolution. Journal of Human Evolution, 55(6), 1156-1159. DOI: 10.1016/j.jhevol.2008.07.004
Carrier, D. (1984) The Energetic Paradox of Human Running and Hominid Evolution. Current Anthropology, 25(4), 483. DOI: 10.1086/203165
Divert, C., Mornieux, G., Freychat, P., Baly, L., Mayer, F., & Belli, A. (2008) Barefoot-Shod Running Differences: Shoe or Mass Effect?. International Journal of Sports Medicine, 29(6), 512-518. DOI: 10.1055/s-2007-989233
Lieberman, D., Venkadesan, M., Werbel, W., Daoud, A., D’Andrea, S., Davis, I., Mang’Eni, R., & Pitsiladis, Y. (2010) Foot strike patterns and collision forces in habitually barefoot versus shod runners. Nature, 463(7280), 531-535. DOI: 10.1038/nature08723
Robbins SE, Gouw GJ, & Hanna AM. (1989) Running-related injury prevention through innate impact-moderating behavior. Medicine and science in sports and exercise, 21(2), 130-9. PMID: 2709977
Unfortunately, the title is not in reference to a study demonstrating that early hominids fell prey to wild dogs. But Elaine Benes would have appreciated it.
As part of my Latitudes Tour, I'm in Nairobi for a couple of days, hoping to spend some quality time with the young Australopithecus boisei kids at the Nairobi National Museum. Recall (that is, if I've mentioned it here?) that my dissertation research is on growth of the lower jaw, in Australopithecus robustus as compared to modern humans. The study of growth obviously requires analyzing individuals across different age groups (an "ontogenetic series" is the fancy term). Admittedly, then, the focus on A. robustus is chiefly because this species has the largest ontogenetic sample of any early hominid (tho at nearly 15 subadults, it's still not as large as one could hope). Also because A. robustus was totally badass.
Australopithecus boisei makes an important comparison for A. robustus, because the two species are allegedly evolutionary 'sisters' - the "robust" australopithecines (though I'm personally not convinced that these two are each other's closest relative). So their growth should be pretty similar. At the same time, though, A. boisei shows much greater adaptations to heavy chewing - they've been referred to as "hyper-robust." So comparing growth in these species should elucidate how their differences arise.
Problem is, there just aren't enough kids! It's like that song by Arcade Fire. Wood and Constantino (2007) published a pretty comprehensive review of A. boisei, including a 1.5-page table of the skulls and teeth attributed to the species. So far as I know, only 4 specimens in this table are subadult mandibles, and so far as I can tell, they're all about the same age (right around the age that the first permanent molar comes in). There are so many jaws of adult A. boisei (although many of these are abraded mandibular bodies lacking teeth) - so how can there be fewer subadults?!?!
A very preliminary observation of infant-child pairs in the two species suggests they both increase in size fairly dramatically between when they only have baby (a.k.a. "deciduous" or "milk") teeth and when the first permanent molar comes in. But this is just a preliminary observation based on 2 specimens of each species! Take with a grain of salt!
On second thought, maybe I'll propose the nearly untestable hypothesis that bone-eating hyenas ate the boisei babes, and that's why we don't have their jaws. What could have been nicely preserved subadult boisei bones are instead coprolites (fossilized poops). A little spectacular, yes, but it's also been hypothesized that many of the A. robustus fossils we know and love came to us as carnivores' scraps.
further reading:Wood, B., & Constantino, P. (2007). Paranthropus boisei: Fifty years of evidence and analysis American Journal of Physical Anthropology, 134 (S45), 106-132 DOI: 10.1002/ajpa.20732... Read more »
Wood, B., & Constantino, P. (2007) Paranthropus boisei: Fifty years of evidence and analysis. American Journal of Physical Anthropology, 134(S45), 106-132. DOI: 10.1002/ajpa.20732
There is one topic which somehow touches almost every major debate in Paleoanthroplogy and this is the question about how speciation actually works. There were a lot of very smart people, who already wrote about this stuff, and I even read some of them. But a large proportion of what I’m going to say about this topic comes from my own thoughts on this topic. So if someone finds a mistake in my arguments, please let me know.When it comes to speciation, there are basically two different opinions on how speciation could work. The first one is sometimes called “punctualistic” or “phylogenetic” and says that speciation usually results in a split in which the ancestral species splits into two different “offspring-species” (there is probably a more suitable term for it, I just can’t remember the English translation).The second one is called “gradualistic” or “anagenetic” speciation and says that one species can, if there is enough time; evolve into another species without any form of splitting.Now although there are many species concepts out there, the main criterion to recognize a species is, if their members are able to interbreed with other animals. This means that no matter what type of speciation process we propose, at some point during this process there has to be some kind of “breeding barrier” (once again, I’ve no Idea how to translate this term), be it either geografical, behavioural or otherwise.Now let’s take a look on how this stuff actually works in case of a punctualistic speciation:Exdample for a punctualistic speciation: Assume a Species "A" lives in a certain habitat "X". Now due to some reasons (e.g. a geological event), a barrier arises in said habitat. This barrier changes the enviroment on both of its sides and furthermore prevents the now separated populations of "A" to exchange their genes. With time, those two sperate populations will adapt to their new enviroments and will become two distinct species.Ok, this was quite easy wasn't it? But how about gradualistic speciation? Her I'll have to admit that although I spent quite some time on this question, I just could come up with one scenario:1. Let’s assume the species we’re looking at is restricted to one habitat2. Let us further assume that all population of said species are able to exchange there genes with on another.3. Now the habitat of said species changes and due to the wonder of natural selection the species adapts to those changes.4. As time goes by the species within that habitat would differ significantly from the species we had before this process started, so that we could safely say that we have discovered a new species.There is only one big problem with this model. If we assume a constant gene flow between the seperate populations of our example species, than this means that there never was any kind of mating barrier at any point in time. So how can we be sure that the species we witnessed at the end of that process isn’t able to interbreed with the species we observed before this whole thing started? Sure, we could assume that since both “forms”, as I might call them right now, are so different that they probably wouldn’t have interbred, if they would’ve lived at the same time.This assumption is pretty similiar to the concept of a “Chrono-species” which defines species solely after their chronological appearances in the fossil record.The Problem here is that we’re not able to test, whether or not, those species really weren’t able to interbreed. It is as always when we have to deal with extinct species, we simply can’t be sure about it. In the end the only safe thing we can say is that every model on the evolution of a certain species, which relies on a gradualistic model of speciation, is highly speculative.There are two recent examples within Paleoanthropology where this Problem occurs. The first one is the possibility to draw a direct line from Australopithecus anamensis to Australopithecus afarensis (Kimbel et al. 2006, Haile-Selassie et al. 2010). The other one are the genetical evidences of interbreeding between modern Humans and Neandertals (Green ... Read more »
KIMBEL, W., LOCKWOOD, C., WARD, C., LEAKEY, M., RAK, Y., & JOHANSON, D. (2006) Was Australopithecus anamensis ancestral to A. afarensis? A case of anagenesis in the hominin fossil record. Journal of Human Evolution, 51(2), 134-152. DOI: 10.1016/j.jhevol.2006.02.003
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
Haile-Selassie, Y., Saylor, B., Deino, A., Alene, M., & Latimer, B. (2009) New hominid fossils from Woranso-Mille (Central Afar, Ethiopia) and taxonomy of early Australopithecus. American Journal of Physical Anthropology. DOI: 10.1002/ajpa.21159
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
In an early view article from the International Journal of Osteoarchaeology, authors Rubini, Cerroni, and Zaio report on the earliest known case of spondylocarpotarsal (SCT) synostosis, found in a middle-aged woman from the Imperial period site of Grottaferrata, near Frascati in the Roman suburbs. The skeleton was found within a large cemetery population (that is completely unpublished in English and, to my knowledge, is not published in Italian either), and the woman's bones were carbon dated to 50-125 AD.
40-45-year-old woman with
SCT syndrome, from Grottaferrata
(credit: Rubini and colleagues, IJOA)
Her skeleton showed immediate evidence of scoliosis, an abnormal curvature of the spine. The authors found atrophy of the left hand, with fusion of all carpals, several metacarpals, and the radius with the scaphoid. There were also numerous segmentation defects in the spine, which they interpret as evidence of congenital scoliosis. All of these bits of fusion and malformation combine to suggest a diagnosis of SCT, which is a rare, autosomal recessive condition. SCT was first described in 1973, and there are only 30 known cases worldwide.
Because of the provenance of the find - the bioarchaeology of Imperial Rome is my wheelhouse, and when I work at Gabii, we stay quite near Grottaferrata - I was interested to learn more about this skeleton and the diagnosis. I can't imagine I'll ever find something like this, since it's such a rare condition, but it was an interesting read.
Rubini M, Cerroni V, & Zaio P (2011). The Earliest Case of Spondylocarpotarsal Synostosis Syndrome (Roman Age—2nd Century AD). International Journal of Osteoarchaeology (Early View).... Read more »
M. Rubini, V. Cerroni, & P. Zaio. (2011) The Earliest Case of Spondylocarpotarsal Synostosis Syndrome (Roman Age—2nd Century AD). International Journal of Osteoarchaeology. info:/
The growth of email, instant messaging, texting, and various other digitally-mediated communicative tools (DMC) has been rapid and pervasive. The majority of people today are comfortable enough to use these communicative tools on a daily basis, particularly among younger generations. DMC appears to be a preferred means of communication. But the popularity of DMC forces [...]
... Read more »
Jack RE, Blais C, Scheepers C, Schyns PG, & Caldara R. (2009) Cultural confusions show that facial expressions are not universal. Current biology : CB, 19(18), 1543-8. PMID: 19682907
Kindred J, Roper S. (2004) Making connections via instant messenger (IM): student use of IM to maintain personal relationships. Qualitative Research Reports in Communication, 48-54. info:/
Wimmer H, & Perner J. (1983) Beliefs about beliefs: representation and constraining function of wrong beliefs in young children's understanding of deception. Cognition, 13(1), 103-28. PMID: 6681741
Wolf, A. (2000) Emotional Expression Online: Gender Differences in Emoticon Use. CyberPsychology , 3(5), 827-833. DOI: 10.1089/10949310050191809
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