Anthropology Daily

theolduvaigorge: Handedness in Neandertals from the El Sidrón...

Tue, 07 May 2013 18:22:17 -0400

Handedness in Neandertals from the El Sidrón (Asturias, Spain): Evidence from Instrumental Striations with Ontogenetic Inferences

by Almudena Estalrrich and Antonio Rosas

“The developed cognitive capabilities for Homo sapiens seems to be the result of a specialized and lateralized brain, and as a result of this, humans display the highest degree of manual specialization or handedness among the primates. Studies regarding its emergence and distribution within the genus Homo show that handedness is present very early. The mode in which it was articulated and spread across the different species during the course of human evolution could provide information about our own cognitive capacities. Here we report the manual laterality attributed to eleven 49,000 old Neandertal individuals from El Sidrón cave (Spain), through the study of instrumental or cultural striations on the anterior dentition. Our results show a predominant pattern addressed to right-handers. These results fit within the modern human handedness distribution pattern and provide indirect evidence for behavior and brain lateralization on Neandertals. They support the early establishment of handedness in our genus. Moreover, the individual identified as Juvenile 1 (6–8 years old at death), displays the same striation pattern as the adult Neandertals from the sample, and thereby the ontogenic development of manual laterality in that Neandertal population seems to be similar to that of living modern humans” (read more/open access).

***About to read this.

(Open access source: PLoS ONE 8(5): e62797)

theolduvaigorge: alphacaeli: theolduvaigorge: The Earliest...

Tue, 30 Apr 2013 18:59:15 -0400

theolduvaigorge:

alphacaeli:

theolduvaigorge:

The Earliest Hominins: Sahelanthropus, Orrorin, and Ardipithecus

By Denise F. Su (Cleveland Museum of Natural History)

“The first members of the human lineage lack many features that distinguish us from other primates. Although it has been a difficult quest, we are closer than ever to knowing the mother of us all.

Until recently, the evolutionary events that surrounded the origin of the hominin lineage — which includes modern humans and our fossil relatives — were virtually unknown, and our phylogenetic relationship with living African apes was highly debated. Gorillas and chimpanzees were commonly regarded to be more closely related to each other due to their high degree of morphological and behavioral similarities, such as their shared mode of locomotion — knuckle-walking. But with the advent of molecular studies it has become clear that chimpanzees share a more recent common ancestor with humans, and are thus more closely related to us than they are to gorillas (e.g., Bailey 1993, Wildman et al. 2003). The similarities between the living African apes were thought to have been inherited from a common ancestor (=primitive features), implying that the earliest hominins and our last common ancestor shared with chimpanzees had features that were similar, morphologically and behaviorally, to the living African apes (Lovejoy 2009). With the discoveries of the earliest hominin species discussed below, it is now possible to critically examine these assumptions.

The chimpanzee-human divergence date has been estimated to be between 8 and 5 million years ago (MA) since the 1960s through immunologic and molecular techniques (e.g., Steiper & Young, 2006). Driven largely in part by these new genetic-based hypotheses, there have been intensive efforts by different teams over the last two decades to find and explore sediments that record this crucial time period for which we had virtually no fossil evidence. Their hard work and perseverance led to the discovery of several new genera and species of early hominins that are dated close to the estimated divergence dates for chimpanzees and humans. In 1994, Ardipithecus ramidus (ca. 4.4 Ma) was announced (White et al. 1994, 1995, WoldeGabriel et al. 1994) and soon after, even older hominins were discovered: Orrorin tugenensis (6.0-5.7 Ma, Pickford & Senut 2001, Senut et al. 2001, Sawada et al. 2002), Sahelanthropus tchadensis (7-6 Ma, Brunet et al. 2002, 2005, Vignaud et al. 2002), and Ardipithecus kadabba (5.8-5.2 Ma, Haile-Selassie 2001, Wolde Gabriel et al. 2001)” (read more/open access).

(Open access source: Nature Education Knowledge 4(4):11, 2013)

Just a note on Sahelanthropus tchadensis. (I’m lifting this more or less verbatim from an earlier post I wrote because this article cites an article that I think is problematic.)

The difficulty with interpreting TM 266 is that it’s fairly heavily distorted. Zollikofer et al. (2005) attempted to reconstruct/3D model S. tchadensis without the distortion and in this reconstruction (which the article rather uncritically cites) the position of the foramen magnum, the length of the nucal plane and the foramen magnum-orbital plane angle, when taken on their own, are all suggestive of obligate bipedalism . On further inspection, though, it’s pretty apparent that something is wrong: the angle between the orbital plane and the foramen magnum is about 90 degrees, indicating an upright posture greater than even that of the australopithecines. Highly unusual.

Investigating this anomaly further, Wolpoff et al. (2006) conducted a (very convincing, in my opinion) biomechanical assessment of the reconstructed skull and found that it could not have functioned in a vertical posture because of the length of the nuchal plane and vertical height of inion: the nuchal plane is exceptionally long and even with the greatly reduced nuchal angle of the reconstruction, and its most posterior extent is significantly above the Frankfurt Horizontal. The cranial rear and posterior portion of the cranial base (its size, shape, and orientation of the nuchal plane) of TM 266 reflects nuchal functions similar to those of apes. In essence, all these things are compatible with a chimpanzee mode of locomotion.

Unlike australopithecines, the evidence indicates that Salehanthropus was not bipedal.This on its own contrasts with all known hominids, and even in the absence of postcranial remains (though there is potentially a femur associated with Toumai) this anatomy is sufficient to exclude Sahelanthropus from the human clade as it is currently understood. This compatible with genetic estimates of the chimpanzee/hominid divergence.

So, at least in my somewhat-educated opinion, TM 266 is more closely related to apes than hominids. I imagine that the femur, if it is ever formally described, will probably tell a similar story.

"I’m not sure how anthropology fits into the contemporary market economy. But I do know that if..."

Thu, 25 Apr 2013 15:12:00 -0400

““I’m not sure how anthropology fits into the contemporary market economy. But I do know that if we don’t pay heed to what anthropological knowledge can teach us, it impoverishes social life and social relations, making us less able to find a measure of well-being in life, less able to be comfortable in our skins.””

- Paul Stoller

4,400-year-old “royal” skeleton unearthed near...

Mon, 22 Apr 2013 21:45:00 -0400

4,400-year-old “royal” skeleton unearthed near historic European town

The discovery of the 4,400-year-old burial site of a woman adorned with gold jewellery has prompted speculation that Windsor’s royal connection goes back further than suspected. Archaeologists working in a quarry near the royal family’s Berkshire residence have unearthed a rare Copper Age grave of a middle-aged woman buried with some of Britain’s oldest gold ornaments.

Read More

theolduvaigorge: Trabecular bone microstructure scales...

Mon, 18 Mar 2013 18:32:11 -0400

theolduvaigorge:

Trabecular bone microstructure scales allometrically in the primate humerus and femur

by Timothy M. Ryan and Colin N. Shaw

“Most analyses of trabecular microarchitecture in mammals have focused on the functional significance of interspecific variation, but they have not effectively considered the influence of body size or phylogeny on bone architecture. The goals of this study were to determine the relationship between trabecular bone and body size in the humeral and femoral heads of extant primates, and to assess the influence of phylogeny on bone microstructure. Using a sample of 235 individuals from 34 primate species, ranging in body size from 0.06 to 130 kg, the relationships between trabecular bone structure and body size were assessed by using conventional and phylogenetic regression analyses. Bone volume fraction, trabecular thickness and trabecular spacing increase with body size, whereas bone surface-area-to-volume ratio decreases. Shape variables such as trabecular number, connectivity density and degree of anisotropy scale inversely with size. Most of these variables scale with significant negative allometry, except bone surface-area-to-volume ratio, which scales with slight positive allometry. Phylogenetic regressions indicate a relatively weak phylogenetic signal in some trabecular bone variables. These data demonstrate that, relative to body size, large primates have thinner and more tightly packed trabeculae than small primates. The relatively thin trabeculae in large primates and other mammals, coupled with constraints on trabecular thickness related to osteocyte function, suggest that increased skeletal loads in the postcranial joints of large mammals are probably mitigated not only through alterations in trabecular microarchitecture, but also through other mechanisms such as changes in cortical bone distribution, limb posture and gait speed” (read more/open access).

(Source: Proceedings of the Royal Society B, 2013 280, 20130172, 2013)

quincourier: Two examples of prehistoric rock art, images taken...

Sun, 17 Mar 2013 15:53:23 -0400

quincourier:

Two examples of prehistoric rock art, images taken from Prehistoric Art by Paul Bahn, 1998

oosik: Amazing 5,000-year-old skeletons laid on bed of flowers...

Fri, 08 Mar 2013 12:58:48 -0500

oosik:

Amazing 5,000-year-old skeletons laid on bed of flowers found in Sahara - proving desert was once green and lush

A tiny woman and two children were laid to rest on a bed of flowers 5,000 years ago in what is now the barren Sahara Desert.

Researchers discovered the slender arms of the youngsters still extended to the woman in a perpetual embrace.

The remarkable cemetery is providing clues to two civilisations who lived there, a thousand years apart, when the region was moist and green.

Paul Sereno of the University of Chicago and colleagues were searching for the remains of dinosaurs in the African country of Niger when they came across the startling find.

Some 200 graves of humans were found during fieldwork at the site in 2005 and 2006, as well as remains of animals, large fish and crocodiles.

‘Everywhere you turned, there were bones belonging to animals that don’t live in the desert,’ said Sereno.

‘I realized we were in the green Sahara.’

The graveyard, uncovered by hot desert winds, is near what would have been a lake at the time people lived there. It’s in a region called Gobero, hidden away in Niger’s forbidding Tenere Desert, known to Tuareg nomads as a ‘desert within a desert.’

The human remains dated from two distinct populations that lived there during wet times, with a dry period in between. … Read more.

"Well, evolution is a theory. It is also a fact. And facts and theories are different things, not..."

Tue, 26 Feb 2013 02:15:14 -0500

“Well, evolution is a theory. It is also a fact. And facts and theories are different things, not rungs in a hierarchy of increasing certainty. Facts are the world’s data. Theories are structures of ideas that explain and interpret facts. Facts do not go away when scientists debate rival theories to explain them. Einstein’s theory of gravitation replaced Newton’s, but apples did not suspend themselves in mid-air, pending the outcome. And humans evolved from apelike ancestors whether they did so by Darwin’s proposed mechanism or by some other, yet to be discovered.”

- Evolution as Fact and Theory, Stephen Jay Gould (via serialmatrix)

theolduvaigorge: Symbiosis ; Land of Neanderthals (short...

Mon, 25 Feb 2013 12:03:33 -0500

theolduvaigorge:

Symbiosis ; Land of Neanderthals (short 3’ clip)

Y.N Productions

Written and directed by R. Hope

52’ for Montagne TV (spring 2013).

“We venture on a trail into our distant past, asking; who were the Neanderthals?

The answer, in part, lies entangled in the ancient hinterlands of Neanderthal territories. In those territories numerous caves conceal Neanderthal debris, including their discarded flint tools. Petrological analysis of those flints fingerprints the provenance sites of these tools to specific outcrops within the landscape. Through this, we now understand where Neanderthal went through the land…

Rob Hope follows the trail in a quest to understanding these enigmatic nomads… and meets with specialists J P Raynal, M H Moncel, Camille Daujeard and J Combier of France’s CNRS research department, as well as Svante Pääbo, of the Max Planck Institute and A Defleur.”

(film and text source: Rob Hope; via @ElNeandertal on Twitter)

shaft of femur

Sat, 23 Feb 2013 00:17:25 -0500

What about it?

theolduvaigorge: Fossils in Acheulean Handaxes Top image: An...

Wed, 13 Feb 2013 20:19:09 -0500

theolduvaigorge:

Fossils in Acheulean Handaxes

Top image: An Acheulean handaxe knapped around a Cretaceous fossil of the bivalve Spondylus spinosus (West Tofts, Norfolk, England).

Bottom image: An Acheulean handaxe knapped around an echinoid Conulus fossil (Middle Gravels: Swanscombe, Kent, England).

For further information see:

Lycett, S.J. 2008. “Acheulean variation and selection: does handaxe symmetry fit neutral expectations?,” Journal of Archaeological Science 35(9):2640-2648.

McNamara, K.J. 2007. “Shepherds’ crowns, fairy loaves and thunderstones: the mythology of fossil echinoids in England,” Piccardi, L and Masse, W.B. (eds.,) Myth and Geology. London: The Geological Society: 279-294.

Nowell, A. and Chang, M.L. 2009. “The Case Against Sexual Selection as an Explanation of Handaxe Morphology,” PaleoAnthropology, 77-88.

Saragusti, I., Sharon, I., Katzenelson, O., and Avnir, D. 1998. “Quantitative Analysis of the Symmetry of Artefacts: Lower Paleolithic Handaxes,” Journal of Archaeological Science 25(8):817-825.

(Image sources: Museum of Anthropology and Archaeology, London and The Geological Society, London).

New analysis of King Tut’s DNA A genetic investigation by French archaeologist Marc Gabolde...

Tue, 12 Feb 2013 20:45:14 -0500

New analysis of King Tut’s DNA

A genetic investigation by French archaeologist Marc Gabolde is threatening to rewrite the history books on two of ancient Egypt’s most iconic figures. For years, antiquities experts have assumed that Akhenaten and his unnamed sister were the parents of the world’s most famous pharaoh, Tutankhamun. And in fact, recent DNA analyses suggested as much. But as Gabolde’s new interpretation of the genetic data shows, King Tut’s mom may have been none other than his father’s first cousin, Nefertiti.

aperilousjourney: the-epistolary: The badass female pioneers...

Wed, 06 Feb 2013 16:53:42 -0500

aperilousjourney:

the-epistolary:

The badass female pioneers of archaeology.

From left to right, top to bottom:

1. Gertrude Bell: was a writer, archaeologist, political officer, traveller and administrator, who helped shape British policy in the Middle East and the creation of the modern state of Iraq. She was described as “one of the few representatives of HIs Majesty’s Government remembered by the Arabs with anything resembling affection.”

2. Mary Leakey: developed a system of classifying the tools she and her husband excavated from the Olduvai Gorge. She was responsible for the discovery of the Proconsul skull, the Zinjanthropus skull and the Laetoli footprints.

3. Amelia Edwards: was a novelist, journalist, traveller and Egyptologist. Through her travel writings, she greatly increased public awareness of archaeology and the importance of conserving monuments threatened by tourism, looting and development.

4. Dorothy Garrod: was the first woman to hold an Oxbridge chair, the first female professor at Cambridge, and her work pioneered research in the field of palaeolithic studies. She contributed greatly to the understanding of prehistoric sequences of occupation in palestine.

5. Mary Anning: was a fossil collector, dealer and palaeontologist, whose work radically changed scientific thinking about prehistoric life. She’s most remembered for discovering the Ichthyosaur.

6. Ruth Benedict: challenged the traditional views held by anthropologists and folklorists by shifting the focus away from culture-trait diffusion and towards theories of performance as central to understanding and interpreting culture. Her work emphasised a holistic view of culture, questioning relationships between different elements.

7. Gertrude Caton-Thompson: worked as an archaeologist in Egypt, and undertook the first archaeological survey of the northern Faiyum. She later undertook the first systematic excavation of Yemen, and excavated at Great Zimbabwe. She was also influential in helping Mary Leakey start her career.

8. Hilda Petrie: worked as a copyist under, and later became the wife of, Flinders Petrie. Hilda made herself invaluable as an excavator and archaeologist, her work taking her into cramped uncomfortable quarters. Petrie was so impressed with her skill, that she often was given excavations of her own.

9. Hetty Goldman: was the first woman professor at the School of Humanistic Studies at the Institute for Advanced Study in Princeton. She is well known for her excavations in Turkey and Boetia, and she sponsored the escape of Jewish refugees during the Holocaust.

Not listed: Zora Neale Hurston. She is one of my favorites!!! She did studies and wrote down African American folklore and songs. In the South and Haiti. Also wrote about Voodoo. She is an amazing writer too.

chris-chinnock: I’ve been looking forward to today for ages!...

Mon, 04 Feb 2013 03:08:55 -0500

chris-chinnock:

I’ve been looking forward to today for ages! Finally got to go see the ossuary at Holy Trinity Church, Rothwell, Northamptonshire. Could have stayed for hours. Just scanning the bones I could see revealed various bits of trauma and pathology. Healed broken tibia, osteomalacia in the femur, possible Paget’s disease, amongst others. OMG I didnt want to leave. Possible research ideas abound!

-Phillip Walker, “Bioarchaeological Ethics: A Historical...

Sun, 03 Feb 2013 20:42:06 -0500

-Phillip Walker, “Bioarchaeological Ethics: A Historical Perspective on the Value of Human Remains.”

visiblebody: Osteons (the neat structure that looks like a...

Thu, 31 Jan 2013 21:24:52 -0500

visiblebody:

Osteons (the neat structure that looks like a tower in the photo) Osteons are structural units of compact bone. Each osteon consists of a central canal, which contains nerve filaments and one or two blood vessels, surrounded by lamellae. Lacunae, small chambers containing osteocytes, are arranged concentrically around the central canal.

Want to learn more about bone anatomy? Check out our latest blog post HERE!

Anterior and posterior views of the proximal femur, reflecting...

Wed, 30 Jan 2013 20:47:40 -0500

Anterior and posterior views of the proximal femur, reflecting on sites of muscle attachment.

radiologysigns: SALTR - a useful memonic to help remember the...

Tue, 29 Jan 2013 02:48:53 -0500

radiologysigns:

SALTR - a useful memonic to help remember the five types of growth plate fracture (Salter-Harris classification). Fortunately the order also directly relates to prognosis from best to worse.

S - slipped = type I

A - above = type II

L - lower = type III

T - through or transverse or together = type IV

R - ruined or rammed = type V

Your molar roots are leftovers from Homo erectus

Sat, 26 Jan 2013 22:56:53 -0500

Your molar roots are leftovers from Homo erectus:

deconversionmovement:

TALK about exploring your roots. Longer lifespans mean our adult teeth erupt later than they did in our early ancestors, but the memo didn’t make it to the roots of our molars. They develop at the same pace as they did in Homo erectus.

Christopher Dean and Tim Cole at University College London studied the microscopic structure of adult molars to reconstruct the pace of their development, much like tree rings can be used to build a picture of tree growth. They found that the roots of chimpanzee molars go through a growth spurt as the teeth erupt through the gum - probably to provide more stability for biting and chewing. The same thing happened in early hominins, but not in modern humans: by the time our molars arrive, their roots have been fully developed for at least a year.

Continue Reading

oldowan: Australopithecus garhi, Adrie and Alfons Kennis...

Sun, 13 Jan 2013 16:02:27 -0500

oldowan:

Australopithecus garhi, Adrie and Alfons Kennis (Atapuerca.tv)

Australopithecus garhi: A hominin speciation event took place in Africa between 2,6 and 2,9 mya that resulted in two or more lineages with distinct adaptations (Suwa et al. 1996). From this speciation event Australopithecus garhi, among other species and genera, arose. The holotype is a unique amalgam of plesiomorphic and apomorphic features.

Specimens: Australopithecus garhi specimens comprise three individuals. The type specimen, BOU-VP-12/130, is comprised of a frontal, parietal and maxilla with dentition. It was recovered from the Hata Member sediments in the Bouri Peninsula, (Middle Awash of Ethiopia) and has been dated by radioisotopic dating of tephra to ≈2,5 mya. It has been the source of animated discussion as concerns its phyletic allocation (Asfaw et al. 1999; Mai et al. 2005) and has been placed in the megadont archaic hominin hypodigm specific to fossils from the Hata Member (Wood 2010).

Similarities and differences with earlier Australopithecines: Au. garhi has been placed in the genus Australopithecus owing to its numerous similarities with other Australopithecines. It has, for example, a cranial capacity of about 450 cc, similar to that of Au. afarensis, thick dental enamel and a shallow anterior palate with a convex subnasal surface (Kimbel 2007). It shows several other primitive conditions including an incisor alveoli anterior to the bicanine line, procumbent incisors and a step from the posterior nasal clivus to the nasal floor (Asfaw et al. 1999; Cameron and Groves 2004). In comparison to more robust Australopithecines, it exhibits a number of Homo-like traits including larger molars. It also has more forwardly positioned cheekbones, a more rounded anterior alveolar margin and more ovoid premolars. It is unlike more robust Australopithecines in its occlusal form and enamel thickness. The parietal, which appears to be male, exhibits a fused sagittal crest but lacks the strong posterior emphasis exhibited by many Au. afarensis specimens (Kimbel 2007). Because of its dissimilarities with earlier Australopithecines, Strait and Grine (2001) do not consider Au. garhi to be a species of Australopithecus but instead suggest it should be placed in the genus Praeanthropus or its own genus.

Other morphological traits: Au. garhi is described as having maxillary prognathism; unique canines with large occlusal areas and distinctive morphology; short legs; a short trunk, and arms that are long by comparison (Simpson 2010). It has been estimated to be 140 cm. However, the postcrania unearthed from the same horizon as the skull have not been formally classified as Au. garhi and other more gracile specimens such as those recovered at Gamedah (Middle Awash), date to a similar age. Furthermore, the supraorbital torus is less robust with greater lateral and weaker medial development than earlier specimens; the squama is somewhat rounded; the glabella region is broad but not inflated; the frontal sinus is small and restricted to the mid-frontal above the glabella; the nasal clivus is more convex and there is a deep canine fossa (Cameron and Groves 2004).

Phyletic association: It has been proposed that Au. garhi is a transitional species between Au. afarensis and early Homo but this assertion is far from universally accepted. The position has been proposed due to a number of Homo-like morphological aspects such as supposed apomorphic crown proportions (Simpson 2010). The distinctive composition of the skull confuses classification. The cranium has been described as possessing a number of primitive (Au. afarensis-like) and derived (Au. africanus-like) traits (Kimbel 2007). Others suggest that as more data are published, Au. garhi will be subsumed into P. robustus. Given that other morphologically distinct specimens have been found in the Afar Depression, it is possible that several taxa were extant circa 2,5 mya. For further analysis of Australopithecus and Praeanthropus phylogeny including Au. garhi, see Cameron and Groves (2004:105) and Cameron (2003).

Dietary hypothesis: The above images depicts Au. garhi eating meat. It has been postulated that Au. garhi consumed animal flesh, which led to an increase in brain size and decrease in molar size that affected other aspects of the skull. This hypothesis suggests that Au. garhi is the ancestor of the genus Homo (Mai et al. 2005), a position that, as stated, is polemical.

Lithic association: Stone tools and fauna with anthropogenic cut marks have not yet been found in direct association with any Au. garhi fossils but have been found in its vicinity at sites around Bouri dated to ≈2,5 mya (de Heinzelin et al. 1999). However, specimens of Homo dated to ≈2,3 mya have been recovered in this locality as well, complicating any association of the stone tools with Australopithecines.

References:

Asfaw. B., White, T., Lovejoy, O., Latimer, B., Simpson, S. and Suwa, G. 1999. “Australpithecus garhi: a new species of early hominid from Ethiopia,” Science 284: 629-635.

Cameron, D.W. 2003. “Early hominin speciation at the Plio/Pleistocene transition,” Homo 54(1):1-28.

Cameron, D.W. and Groves, C.P. 2004. Bones, Stones and Molecules: “Out of Africa” and Human Origins. Elsevier.

de Heinzelin, J, Clark, J.D., White T.D., Hart, W., Renne, P., WoldeGabriel, G., Beyene, Y. and Vrba, E. 1999. “Environment and behavior of 2.5-million-year-old Bouri hominids,” Science 284: 625-629.

Kimbel, W.H. 2007. “The species and diversity of Australopiths,” Winifred Henke and Ian Tattersall (eds.,). Handbook of Paleoanthropology. Springer: 1539-1574.

Mai, L.L, Young Owl, M., Kersting M.P. 2005. The Cambridge Dictionary of Human Biology and Evolution. Cambridge University Press.

Simpson, S.W. 2010. “The Earliest Hominins,” Clark Spencer Larsen (ed.,). A Companion to Biological Anthropology. Wiley-Blackwell: 314-340.

Strait, D.S. and Grine, F.E. 2001. “The systematics of Australopithecus garhi,” Ludus Vitalis 9: 109-135.

Suwa, G., White, T.D. and Howell, F.C. 1996. “Mandibular postcanine dentition from the Shungura Formation, Ethiopia: crown morphology, taxonomic allocations, and Plio-Pleistocene hominid evolution,” American Journal of Physical Anthropology 101: 247-282.

Wood, B. 2010. “Reconstructing human evolution: achievements, challenges, and opportunities,” John C. Avise and Francisco J. Ayala (eds.,). In the Light of Evolution, vol. IV: The Human Condition. National Academic Press: 5-26.

Phew! I’m sure I made some mistakes. Let me know.