A complete 1.8 million year old skull found from Dmanisi, Georgia could be evidence that early hominids are actually all members of a single species. Researchers published their analysis in Science today and argue that the skull’s combination of primitive and more evolved features, such as a small braincase (546 cubic cm) with a large prognathic face.., Similar morphological affinities with the earliest known Homo fossils from Africa, which make it difficult to classify by now accepted definitions of early hominid species.
Nature Communications published an article in May, 2013 that just now caught my eye. The paper’s title, “Development of Middle Stone Age innovation linked to rapid climate change,” lays down a solid understanding of what the authors found… The one line summary of the article is: the authors observed that very abrupt changes in rainfall in South Africa, about 40,000 – 80,000 years ago, correlated with the development of new technologies.
The global climate of last million years varied between glacial and interglacial periods. These changes occurred about every 100,000 years. But within these long-term periods there have been shorter blips of climate changes, sometimes happening in the span of just a few decades. During these short blips, variations of up to 10ºC in the average temperature of the polar regions are caused by changes in the Atlantic ocean circulation, which ultimately affected rainfall in southern Africa.
By analyzing river delta deposits, the researchers of this paper have pieced together how rainfall patterns varied in southern Africa over the last 100,000 years. Every millimeter of sediment core corresponds to 25 years of sedimentation. The ratio of iron to potassium in the layers is a record of the sediment carried by rivers and of the rainfall throughout the period. With that the authors were able to see patterns in the climate… As the South African climate changed rapidly towards more humid conditions, the northern sub-Saharan Africa experienced widespread droughts, and the Northern Hemisphere entered phases of extreme cooling.
The reconstruction of the rainfall over 100,000 years shows a series of spikes that occurred between 40,000 and 80,000 years ago. These spikes show rainfall levels rising sharply over just a few decades, and falling off again soon afterwards, in a matter of centuries. The climate changes coincided with abrupt emergence of material culture and modern behaviour such as the beginnings of symbolic expression, the making of tools from stone and bone, jewellery and the first agricultural settlements. And in turn, the end of certain stone tool industries of the period coincides with the onset of a new, drier climate.
The findings confirm one of the principal models of Palaeolithic cultural evolution, which correlates technological innovation with the adoption of new refuges and with a resulting increase in population and social networks.
- Climate ‘spurred human innovation’ (bbc.co.uk)
- Climate Change Sparked Stone Age Technological Innovation in Modern Humans (scienceworldreport.com)
- Abrupt climate shifts spurred Stone Age innovation in Africa (latimes.com)
- Origins of human culture linked to rapid climate change (sciencedaily.com)
Linguist Carmel O’Shannessy wrote to the journal Language of a newly discovered language, Light Warlpiri. Her correspondence, “The role of multiple sources in the formation of an innovative auxiliary category in Light Warlpiri, a new Australian mixed language,” documents 300 people in a remote desert community about 644 kilometres from Katherine, a town in Australia’s Northern Territory, speaking in a striking auxillary system. She believes it emerged in the 1970′s and 80′s.
The language draws on traditional Warlpiri, which is spoken by about 6,000 people in indigenous communities scattered throughout the Tanami Desert along with Kriol, an English-based Creole language spoken in various regions of Australia; and English. In the Warlpiri language, words can be placed in any order, and grammatical interpretations are based on suffixes that are attached to the nouns. And the imported words have changed meanings so that the structure of the auxiliary model is not the same as they were in the source languages. O’Shannessy explains,
“In Light Warlpiri, you have one part of the language that mostly comes from English and Kriol, but the other grammatical part, the suffixing, comes from Warlpiri.”
Another distinction of the newfound language is a word form that refers to both the present and past time, but not the future. For example, in English, “I’m: refers to “I” in the present tense, but Light Warlpiri speakers created a new form, such as “yu-m,” which means “you” in the present and past time, but not the future.
“That structure doesn’t exist in any of the languages that this new code came from, which is one of the reasons we see this as a separate linguistic system, even though it comes from other languages that already exist,
Here’s an interesting example. Blue words in this color are from Warlpiri, and those in that are red are from English or Kriol. Green colored words are for the creative auxiliary system and verbal structure.
De-m run back rarralykaji-kirra jarntu an yapa-wat ngapa-kujaku.
“The dog and the people run back to the car to get out of the rain.”
Agent-based model, brain, Dunbar's number, Encephalization Quotient, Group size measures, human evolution, Oxford University, Proceedings of the Royal Society, Robin Dunbar, social brain hypothesis, Social group
An Oxford University team of two led by Tamás Dávid-Barrett published an open access paper in the Proceedings of the Royal Society B testing the social brain hypothesis. In a nutshell, the social brain hypothesis was created by the other author of this paper, Robin Dunbar, who theorized in 1993 with anthropologist Leslie Aiello, that intelligence among humans is a function of surviving and reproducing in large and complex social groups and not solving ecological problems.
In order to investigate their hypothesis, they looked at Encephalization Quotient is a measure of brain size relative to body size. The cat’s EQ of about 1, which is expected for its body size. But most primates have brains that are larger than expected for their body size. Chimps have an EQ of 2.5. Humans have almost three times as much, at around 7.5. Dolphins have an EQ of more than 5, and rats and rabbits are way down on the scale — below 0.4. Aiello and Dunbar published their findings, along with a run down in the fossil record, in the widely cited 1993 paper in Current Anthropology. They correlated that the larger a species’ group size, then the larger its brain—particularly the neocortex, the outer layers where most of the serious thinking goes on.
The current paper, “Processing power limits social group size: Computational evidence for the cognitive costs of sociality,” describes how the authors used agent-based modelling to serve up coordination problems to agents. Solving these problems required synchrony of behaviors, meaning each agent had to do the right thing and the right time in just the right way for the group to progress. In effect they simulated in computer models.
They found out that the viability of group size increased as calculation, or figuratively speaking cognitive, capacity increased. Furthermore, their simulations demonstrated the need for complex language through the situations where group size increased and the agents had to switch to deeper information processing strategies that allowed them to differentiate among their problems.
I like research like this, however I do not appreciate how it is digested and regurgitated in the press. The press is running headlines like “Big brains developed big brains to deal with society,” implying that evolution has some goal or some design. This is not true. It is true however, sociality is a selective pressure. And to be social required large frontal lobes, but is not the sole region for human intelligence.
- Study confirms social brain theory (bbc.co.uk)
american anthropological association, anthropology, Cultural Anthropology, Forbes, Kiplinger, New York City Department of Sanitation, Orlando Sentinel, Savage Minds, Social Sciences, University of Central Florida
In December, I linked up Ann Gibbons’ article in Science about anthropology’s poor reception in the scientific community. I forgot to mention that months before that, in August, Kiplinger named anthropology “the worst major for your career.” Two months later, Forbes followed suite and ranked “anthropology and archaeology,” as the No. 1 on its list of “worst college majors.”
Suffice to say, 2012 was a tough year for anthropology, but at least we were number #1 in something! But all kidding aside, increased discussion is a positive outcome from all this criticism. What needs to be done is to increase the worth of studying anthropology.
In April of this year, Ty Matejowsky and Beatriz M. Reyes-Foster, two anthropologists from the University of Central Florida, wrote a guest column in the Orlando Sentinel, on the issue of the lack of “cool” factor in cultural anthropology. They have an empowering message,
Anthropologists need to take better ownership of our brand. The complexity of anthropological concepts such as “culture,” “power” and the “global” should not dissuade anthropologists from engaging in meaningful public discourse.
A couple of days ago, Savage Minds tackled the Orlando Sentinel guest column, saying our problem with our field is not just due to how we sell or brand ourselves, but in actuality how we conduct our work.
And last week, in the AAA blog post Anthropology News continued this discussion. Jennifer Long wrote, “Anthropology’s Response to Finding Jobs for Its Undergraduates.” Her approach general cites that anthropology is rather incestuous. Often those interested in anthropology gain positions within universities as researchers, which creates a bubble. She advocates for an experiential approach, to branch out and apply our field elsewhere… Much like Robin Nagle, an anthropologist-in-residence at the New York City Department of Sanitation. Robin has recently written about trash and how our lives revolved around it. The book is titled, “Picking Up: On the Streets and Behind the Trucks with the Sanitation Workers of New York City,” and Collector’s Weekly interviewed her about it and the NY Times covered a book review about it.
With all this discussion about what’s wrong with anthropology, I want to turn to you, the readers and hear what you think is wrong with the field. Please feel free to comment and let us know what you find issue with the field — is it a branding problem; is it a problem with branching out and how we work?
Last Friday, Ivan Sprajc led a group of researchers to a site in Campeche, a province in the western Yucatán peninsula, that he initially identified via stereoscopic aerial photographs. He and his group found the ruins of an enormous 54 acre (22 hectares) city, full of artifacts.
The city is named Chactún. Chactún was occupied during the Late Classic Maya period, which spans roughly A.D. 600 until A.D. 900. Some interesting finds include three monumental complexes with the remains of pyramids — one 75 feet (23 meters) high. In addition, they’ve identified ball courts, plazas, homes, altars, bits of painted stucco and stone slabs known as stele. One stele refers to an apparent ruler named K’inich B’ahlam.
Unlike other large Mayan cities, Chactún has never been studied by archaeologists before. I’m eager to see what comes from this city, and what insights it provides. Other interesting methods to find archaeological sites have been used in the past, which I’ve written about here, here and here.
The internets are buzzing about the news of the earliest known bone tumor on record, predating others by more than 100,000 years. The tumor has been found on the left rib of a 120,000 year old Neandertal from Krapina, Croatia. The original paper is published under the title, “Fibrous Dysplasia in a 120,000+ Year Old Neandertal from Krapina, Croatia” in the journal PLoS ONE.
In the world of pathology, there are many terms to describe growth such as metaplasia, hypertrophy, neoplasia, hyperplasia and dysplasia. Dysplasia defines abnormal growth where cell differentiation is delayed. If a cell is committed to of one of the three germ lines, say ectodermal, a dysplastic cell of that lineage would then remain a ectodermal precursor and not differentiate into the nervous tissue or skin appendage it was programmed to become.
Bone is composed of two types of tissue, compact and trabecular. Compact bone is the dense, outside structure while trabecular or spongy bone is the fibrous layer that you often do not see. Fibrous dysplasia, therefore refers to the abnormal maturation of trabecular bone. Fibrous dysplasia is a benign, non-hereditary process. It was first described in the 1942 by Lichtenstein and Jaffe. The disease process may be localized to a single bone (monostotic) or multiple bones (polyostotic). Up to 80% of cases are monostotic.
Polyostotic fibrous dysplasia can occur as a part of McCune-Albright syndrome. McCune-Albright Syndrome often affects unilateral bones with ipsilateral café-au-lait spots on the skin, and endocrine disturbances such as precocious puberty. Fibrous dysplasia has also been reported in association with other endocrine dysfunctions such as hyperthyroidism, hyperparathyroidism, acromegaly, diabetes mellitus, and Cushing syndrome as well as an associated abnormality in Neurofibromatosis type II. Malignant transformation of fibrous dysplasia is very infrequent, with reported prevalences ranging from 0.4% to 4%.
We know that fibrous dysplasia is caused by a somatic mutation in the GNAS1 gene on chromosome 20q13.2-13.3. GNAS1 encodes the alpha subunit of the stimulatory G protein, Gsα. As a consequence of this mutation, there is a substitution of amino acid arginine in position 201 of the genomic DNA in the osteoblastic cells, by amino acid cysteine (R201C) or histidine (R201H). The abnormal G1 protein stimulates cAMP. Furthermore, proto-oncogene levels of C-fos and periostin are raised in fibrous dysplasia. Consequently, the osteoblasts expressing this mutation have a higher rate of DNA synthesis, leading to the formation of a disorganized fibrotic bone matrix with primitive bone formation, and lack of maturation to lamellar bone.
The specimen is Krapina 120.71, a 3 cm long, left rib fragment containing about 2/3rds of the neck, most of the tubercular facet and a small section of the shaft. It is thought to be rib 3-6. It was first unearthed between 1899 and 1905 in a cave known as the Krapina rock shelter in Croatia. This site held more than 900 Neandertal bones dating back 120,000 to 130,000 years ago. Many of the bones display signs of trauma, and a few show post-mortem cutting marks, perhaps indicating cannibalism or some sort of ritual reburial.
In the 1980s, University of Pennsylvania researchers X-rayed the entire collection. They published a book in 1999 showing each radiograph. Most of those X-rays were quite high-quality, but one exception was found in a little rib fragment which appeared “burned out.” That prompted the authors to return to the specimen. They adequately describe an osteolytic abnormality and offer differentials of chondroma, post-traumatic lesion and chronic osteomyelitis, but remain confident with their radiographic diagnosis of fibrous dysplasia via microCT scanning.
Bone lesions in the fossil and archaeological record are extremely rare for several reasons. Without adjacent soft tissue, it is hard to compare normal to abnormal. Furthermore, the decomposition process alters bone dramatically. Previously, the oldest known tumors came from Egyptian mummies and dated back only 4,000 years or so and a 1,600-year-old tumor containing teeth was found in the pelvis of an ancient Roman corpse. So to find a 120,000 year old Neandertal with a osteolytic lesion in the rib is significant.
What I find wrong with this publication is the spin; too often in our world of paleoanthropology do I see issue with people trying to put a particular bend to sell their otherwise interesting story as a sensational headliner. The press is running quotes from the senior author like,
“… indicates that Neanderthals were susceptible to the same types of tumors modern-day humans get, despite living in a remarkably different environment.
‘They didn’t have pesticides, but they probably were sleeping in caves with burning fires,’ says David Frayer, an anthropologist at the University of Kansas and the co-author…”
The problem with the above quotes stem from the conclusion,
“Finally, it is recognized that environmental changes wrought by humans, compounded by population expansion, have resulted in an increase the types and the intensification of the pollutants within the environment, many of which are directly associated with neoplastic disease and were not part of environments in the past . Given these factors, most argue that cases of neoplastic bone disease are rare in prehistoric human populations –. It is against this background that the identification of a 120,000+ year old Neandertal with a primary osteolytic lesion is surprising and one that provides insights into the nature and history of the association of humans to neoplastic disease.”
Putting an emphasis that Neandertals lived in “cleaner” environments and still had susceptibility to the same types tumors is extremely short-sighted. There are most definitely some tumors with strong associations to environmental mutagens, such as tobacco consumption with mouth, throat and lung cancer or asbestos with mesotheliomas… To which I’d venture a hefty bet that Neandertals were not suffering from as much as modern humans are. So to use words like same types of tumors, or phrases like, “lived their lives basically the same way we did and basically with the same problems that we have,” is a stretch.
As explained earlier, fibrous dysplasia is caused a somatic mutation of the GNAS1 gene. Somatic mutations are acquired before birth, in utero, early in fetal development where DNA replication occurs at a rapid rate and errors can be made all throughout. The authors fundamentally neglect a discussion that most mutations are inherent problems in DNA replication, repair, tautomerism, depurination, deamination, and slipped strand mispairing. A one-sided discussion that one benign bone lesion in one individual is indicative that prehistoric humans contracted the same cancers we do, despite environment, and had the same problems we have is incomplete.
Can we agree to just focus on the science and not extrapolate a faulted connection?
Monge, J., Kricun, M., Radovčić, J., Radovčić, D., Mann, A., & Frayer, D. (2013). Fibrous Dysplasia in a 120,000+ Year Old Neandertal from Krapina, Croatia PLoS ONE, 8 (6) DOI: 10.1371/journal.pone.0064539
- Fibrous Dysplasia in a 120,000+ Year Old Neandertal from Krapina, Croatia (plosone.org)
- World’s oldest tumour found in the rib of Neanderthal that lived 130,000 YEARS ago (dailymail.co.uk)
- Tumor in Bone Shows Neanderthals Got Cancer Too (news.health.com)
- Bone tumor identified in 120,000-year-old rib of Neandertal (princeton.edu)
- Earliest Evidence of Bone Tumor Discovered in Neanderthal Fossil (scienceworldreport.com)
- Oldest Cancer Ever?: 120,000-Year-Old Bone Tumor Found In Neanderthal Fossil (medicaldaily.com)
- Neanderthals Got Tumors, Too (newser.com)
- The Neanderthal With the World’s Oldest Tumor (news.nationalgeographic.com)
Last week, PLoS One published a paper re-dating the BH-1 specimen from Balanica. The new dates are 397 and 525 ka. The new dates are at least 280,000 years older than the previously published study. At this time, Neandertal traits were distinct in Europe.
But the mandible fragment features a primitive prominent planum alveolare, and a thick mandibular corpus. The exomolar sulcus is wide. A flat rather than concave sublingual fossa is present. And there is poor definition of the submandibular fossa. Given the size of the mandibular body, and that the dentition is relatively small; there is a complete lack of derived Neandertal features. Ultimately, this specimen fits well with Middle Pleistocene European archaic Homo specimens like Kocabaş, Vasogliano and Ceprano.
With the dates pushed back via electron spin resonance combined with uranium series isotopic analysis and infrared/post-infrared luminescence dating, the authors aim to further their claim that this niche area of the Balkans offered refuge. Unlike their counterparts, these humans in southeastern Europe were never geographically segregated from Asia and Africa by the glaciations that isolated and ultimately speciated other European humans.
Rink, W., Mercier, N., Mihailović, D., Morley, M., Thompson, J., & Roksandic, M. (2013). New Radiometric Ages for the BH-1 Hominin from Balanica (Serbia): Implications for Understanding the Role of the Balkans in Middle Pleistocene Human Evolution PLoS ONE, 8 (2) DOI: 10.1371/journal.pone.0054608
Photographer Klaus Pichler spent three years photographing the depots, cellars, and storage rooms of various museum departments for his Skeletons in the Closet series, giving us a behind the scenes views of the Museum of Natural History in Vienna and captured the exhibits while they aren’t on display. I particularly like this one.