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Forum: Stones Forum
Moderated by : Andy B , TimPrevett , coldrum , Klingon , MickM , TheCaptain , bat400 , davidmorgan , Runemage , SolarMegalith , sem
Respond to: Extinct Subfamily Homininae, Tribe Hominini (was Neanderthals)
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bat400
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from South Central Indiana, US
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|  New Message Posted!2013-05-17 07:30
[b]Fossilized teeth provide new insight into human ancestor[b/]
Submitted by coldrum -
A dental study of fossilized remains found in South Africa in 2008 provides new support that this species is one of the closest relatives to early humans.
The teeth of this species – called Australopithecus sediba – indicate that it is also a close relative to the previously identified Australopithecus africanus. Both of these species are clearly more closely related to humans than other australopiths from east Africa, according to the new research.
The study, published in the journal Science, revealed that both africanus and sediba shared about the same number of dental traits with the first undeniably human species.
"Our study provides further evidence that sediba is indeed a very close relative of early humans, but we can't definitively determine its position relative to africanus, said Debbie Guatelli-Steinberg, co-author of the study and professor of anthropology at The Ohio State University.
The research was led by Joel D. Irish, professor of natural sciences at Liverpool John Moores University.
The sediba fossils were found in South Africa in 2008 and first described in a series of articles published in Science in 2010. That study was led by Lee Berger of the University of Witwatersrand in South Africa, who is also a co-author of this new study.
In this study, Irish, Guatelli-Steinberg and their colleagues extended that work by examining the teeth from sediba and comparing them to eight other African hominin species, which include modern humans from Africa, and extinct species of Homo, Australopithecus, and Paranthropus. In all, the researchers examined more than 340 fossils and 4,571 recent specimens. They also examined teeth from 44 gorillas for comparison.
The focus was on 22 separate traits of tooth crowns and roots that can give clues as to the relationship between the different species studied.
For example, they measured how much one of the incisors was shovel-shaped. Depending on the species in this study, the incisor may have no depression in the back of the tooth, a faint shovel shape, or a trace of that shape.
Researchers use standardized measurements from the Arizona State University Dental Anthropology System to compare the teeth on these 22 traits.
The researchers found that on 15 of these traits, sediba and africanus scored the same. Sediba shared 13 traits with Homo erectus, an early human species, which was comparable to how africanus scored.
Sediba and africanus shared five dental traits that weren't found in earlier australopiths, further showing their close relationship. Both also share five traits with early humans – Homo habilis/rudolfenis and Homo erectus—which weren't shared with earlier ancestors, demonstrating the close relationship between these two australopiths and the first humans.
Teeth are an excellent way to study relationships between different species, Guatelli-Steinberg said. They are well preserved in the fossil record, and researchers can compare large samples, at least for many ancient species.
In addition, most of the dental traits the researchers used in this analysis don't have a selective advantage that could help one species survive over another. That means if researchers see a similar trait in two species, they can be more confident that they shared a common ancestor and that the trait didn't evolve independently.
In many ways, these new dental data support the earlier research on sediba, which included analysis of the inside of the skull, hand, spine, pelvis, foot and ankle, Guatelli-Steinberg said.
"All of the research so far shows that sediba had a mosaic of primitive traits and newer traits that suggest it was a bridge between earlier australopiths and the first humans," she said.
Guatelli-Steinberg said their dental analysis showed that both africanus and sediba are more closely related to humans than the famous "Lucy" skeleton fossil found in East Africa in 1974. This fossil represented a species, Australopithecus afarensis, that was at one time was thought to be the closest relative of humans.
Lucy is estimated to have lived 3.2 million years ago. Sediba lived 1.977 million years ago, while africanus lived between 3.03 and 2.04 million years ago.
"Our research on teeth can't definitively settle if either sediba or africanus is more closely related to humans than the other species," Guatelli-Steinberg said. "But our findings do suggest that both are closely related to each other and are more closely related to humans than afarensis.
"We need to find more sediba remains to help fill in the missing pieces of this evolutionary puzzle."
Read more at: http://phys.org/news/2013-04-fossilized-teeth-insight-human-ancestor.html#jCp
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Andy B
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| New Message Posted!2013-01-22 00:11
Great thread, thanks muchly Bat.
How about this one - Should we try to bring Neanderthals back from the dead?
Besides saying that the cloning of a live Neanderthal baby would be possible in our lifetime, synthetic biology expert Dr. George Church told Der Spiegel magazine (amongest other things) that using stem cells to create a Neanderthal could have significant benefits to society. "The first thing you have to do is to sequence the Neanderthal genome, and that has actually been done," Church said.
I've given this one a new thread as it's a 'mind blowing' proposition for prehistory enthusiasts that I think deserves some discussion.
http://www.megalithic.co.uk/modules.php?op=modload&name=Forum&file=viewtopic&topic=5542&forum=4
Please comment over there rather than below...
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bat400
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from South Central Indiana, US
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| New Message Posted!2013-01-21 05:22
Africa's Homo sapiens were the first techies
The search for the origin of modern human behaviour and technological advancement among our ancestors in southern Africa some 70 000 years ago, has taken a step closer to firmly establishing Africa, and especially South Africa, as the primary centre for the early development of human behaviour.
A new research paper by renowned Wits University archaeologist, Prof. Christopher Henshilwood, is the first detailed summary of the time periods he and a group of international researchers have been studying in South Africa: namely the Still Bay techno-traditions (c. 75 000 – 70 000 years) and the Howiesons Poort techno-tradition (c. 65 000 – 60 000 years).
The paper, entitled Late Pleistocene Techno-traditions in Southern Africa: A Review of the Still Bay and Howiesons Poort, c. 75 ka, has been published online in the Journal of World Prehistory on 6 November 2012.
Henshilwood says these periods were significant in the development of Homo sapiens behaviour in southern Africa. They were periods of many innovations including, for example, the first abstract art (engraved ochre and engraved ostrich eggshell); the first jewellery (shell beads); the first bone tools; the earliest use of the pressure flaking technique, that was used in combination with heating to make stone spear points and the first probable use of stone tipped arrows launched by bow.
"All of these innovations, plus many others we are just discovering, clearly show that Homo sapiens in southern Africa at that time were cognitively modern and behaving in many ways like ourselves. It is a good reason to be proud of our earliest, common ancestors who lived and evolved in South Africa and who later spread out into the rest of the world after about 60 000 years," says Henshilwood.
Thanks to coldrum for the link. For more, see
http://www.eurekalert.org.Page Title
and
http://popular-archaeology.com.
[ This message was edited by: bat400 on 2013-01-21 05:35 ]
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bat400
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from South Central Indiana, US
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| New Message Posted!2013-01-18 18:59
Hominins already inhabited the Three Gorges region of South China in Pleistocene
Systematic archaeological survey and excavations in the Three Gorges region, South China over the past two decades has led to the discovery of a number of important hominin fossils and Paleolithic stone artifact assemblages. Dr. PEI Shuwen, Institute of Vertebrate Paleontology and Paleoanthropology (IVPP), Chinese Academy of Sciences, and his collaborators reviewed the results of recent research from this region, and concluded that Middle to Late Pleistocene hominins already Inhabited the Three Gorges Region of South China and the Paleolithic technology is essentially an Oldowan-like industry. This study was published online in the journal of Quaternary International (2012).
The Three Gorges region is located in the transitional zone between the upper and middle reaches of the Yangtze River (Changjiang River). Systematic field surveys identified sixteen Paleolithic sites in caves and along the fluvial terraces of the Yangtze River. Geomorphology, biostratigraphy, and geochronology studies indicate that these sites were formed during the Middle to Late Pleistocene.
Three Gorges lithics are dominated by Mode 1 core and flake technologies. Lithic raw material exploited in the cave and open-air sites were primarily locally available river cobbles. All flaking is by hard hammer percussion without core preparation. Interestingly, some flakes display evidence that anvil flaking and throwing flaking techniques were also utilized. Core reduction was primarily by unifacial flaking. Unifacial flaking is also demonstrated very clearly from the cortex flakes and platforms.
The stone artifact assemblages from the region include cores, whole flakes, flake fragments and chunks, with a low percentage of retouched pieces. Unifacial choppers are the predominant core categories compared to the bifacial choppers, with sporadic discoids, polyhedrons and bifaces. Major blanks for retouched pieces are dominated by flakes and flake fragments. Retouched pieces appear to be retouched unifacially by direct hammer stone percussion on the dorsal surface of the blanks.
"Overall, the Three Gorges region stone toolkits can be characterized by a general lack of standardization of shape and an absence of formal tool categories. The heavy reliance on locally available, generally poor quality raw materials appears to have influenced the composition and morphology of the stone toolkits in the region", said PEI Shuwen, first author of the study.
"This study indicates that there has been a long history of hominin occupation in the Three Gorges region, said coauthor GAO Xing of the IVPP, "Archaic Homo sapiens and modern H. sapiens identified from some of the cave deposits are likely the hominins responsible for the production of the stone artifacts".
Thanks to coldrum fore the link. For more, see
phys.org/news/.
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bat400
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from South Central Indiana, US
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| New Message Posted!2013-01-17 16:12
Anaemic ancestors
A fragment from the skull of a prehistoric child provides the oldest-known evidence of anaemia caused by malnutrition – suggesting that hominids were regularly eating meat much earlier than previously thought, archaeologists say.
While it is known that early human ancestors did eat meat, it was not previously certain whether this was something consumed frequently, or only a sporadic part of their diet.
Now new research published in the open access journal PLOS ONE suggests that meat-eating was common enough 1.5million years ago that not consuming it could lead to anaemia.
The skull fragment, thought to belong to a child aged younger than two, was found during ongoing excavations at Olduvai Gorge, Tanzania, led by Manuel Dominguez-Rodrigo from Complutense University, Madrid.
Close examination of the piece of bone revealed lesions that commonly result from a lack of B-vitamins in the diet – the first time that such lesions have been observed in a hominid fossil from the early Pleistocene record. Nutritional deficiencies such as anaemia are most common in children during weaning, when an infant’s diet changes significantly.
It is thought that the Olduvai Gorge child may have died when he or she was first starting to eat solid foods but had little access to meat, or if they were still breastfeeding, that their mother might have suffered from malnutrition due to lack of meat, which would have affected the B-vitamin content of her milk.
Either case would imply that ‘early humans were hunters, and had a physiology adapted to regular meat consumption at least 1.5million years ago,’ say the authors.
Thanks to coldrum for the link. For the source article and photos, see http://www.world-archaeology.com
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bat400
Joined:
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from South Central Indiana, US
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| New Message Posted!2013-01-17 13:11
Quote:
| On 2013-01-16 23:03, Feanor wrote:
Thanks for posting these, Bat-400, and for announcing the change of venue.
Though a silent lurker on the other thread, I was an avid reader.
Best,
Neil |
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You're welcome. The old thread was getting a little top heavy. More to come.
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Feanor
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Messages: 316
from Cape Cod Massachusetts, US
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| New Message Posted!2013-01-16 23:03
Thanks for posting these, Bat-400, and for announcing the change of venue.
Though a silent lurker on the other thread, I was an avid reader.
Best,
Neil
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bat400
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Messages: 1331
from South Central Indiana, US
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| New Message Posted!2013-01-16 19:34
Was Narmada valley the centre of human evolution?
Much is known about how the Harappan Civilization flourished on the banks of the Indus almost 5,000 years back. But now is the time to move 'before' the Indus Valley Civilization.
Through the largest exploration exercise ever undertaken, MS University's Department of Archaeology and Ancient History along with United States' Stone Age Institute will unearth evidence of our own ancestors.
MSU and Indiana-based Stone Age Institute have joined hands for the 'Narmada Basin Paleoanthropology Project (NBPA)' with the target to collect all the paleoanthropological evidence within the last two million years.
"This project may throw new light giving credence to the belief that the Narmada Valley could have been the centre of human evolution," says professor K Krishnan, head of MSU's Department of Archaeology and Ancient History.
The project for the period of five years has its roots in the discovery of a vertebrate fossil record including the only pre-modern human fossil known in South Asia from - the Narmada Basin.
In 1980s, former director of Geological Survey of India (paleontologist) Arun Sonakia had created a sensation surprising the world with his discovery of the "only human fossil in Asia" from near Hoshangabad in Central Narmada Valley Basin in Madhya Pradesh which he said was that of a homo erectus (predecessors of today's human). In recent times, however, archaeologists have argued that although the discovery has been variably attributed to different species of homo, its age remains uncertain.
"Study at Narmada Basin is important because of its geographical location which is very strategic for migration of animal population from North to South and East to West. It is not only rich in fossils and archaeological sites, but it has a long history of human occupation and this region is facing submergence due to dam construction," says Chauhan.
"Through the project we are trying to know whether the human evolution in Narmada Valley was the same as other regions - Africa, China or Europe or whether the origin of African and European stone age cultures was the Narmada Valley," he says.
After the team of researchers carries out a systematic survey, excavations will be mainly carried out at sites like Dhansi, Hathnora, Pilikarar, Surajkund, Amonda, Mahadeo-Piparia (most of them located in the area within the limits of Houshangabad region."The study will not only cover the sites that are reported but we are sure that we will come across more number of sites. Most suitable will be chosen for excavation," adds Krishnan.
Thanks to coldrum for the link. For more, see: articles.timesofindia.indiatimes.com. null
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bat400
Joined:
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from South Central Indiana, US
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| New Message Posted!2013-01-16 16:44
Scientists Research First Stone Tool Industries in Olduvai Gorge
An international team of researchers have returned to Olduvai Gorge in Tanzania to unravel the mystery of how humans transitioned from the first stone tool technology to a more sophisticated industry.
Olduvai Gorge, perhaps the most famous site for evidence of early humans, is again the subject of intense research on a decades-old question bearing on human origins: How, when and where did early humans evolve from using the first and simplest stone tool industry, that of Oldowan, to the second-oldest, and more sophisticated, stone tool technology known as the Acheulean?
Advances in archaeological investigative methods and the application of multidisciplinary approaches have made it possible to take another, more detailed and comprehensive look at both the old and the new among the world-famous exposed beds, the geological earthen layers or deposits that have historically produced some of the great ground-breaking discoveries related to early human evolution. Now, under the organizational umbrella of the Olduvai Geochronology Archaeology Project, an international team of scientists composed of a consortium of researchers and institutions is focusing on reconstructing the picture of the early human transition from the simple "chopper" stone tool technology of the Oldowan industry, the world's first technology discovered at Olduvai, to the Acheulean, the more sophisticated technology represented most by the well-known bifacial "handaxe", some of the first examples of which were found at Saint- Acheul in France, and later at Olduvai. The Oldowan is considered to have been made and used during the Lower Paleolithic, from 2.6 to 1.7 million years ago, whereas the Acheulean emerged about 1.76 million years ago and was used by early humans up to about 300,000 years ago or later.
To find answers, the team will be reappraising the chronological stratigraphy of Bed II, known to have yielded previous significant finds, and will be re-excavating some of the later beds of the best known fossil and stone tool sites. These beds reveal a record of a very important time period (1.79 - 1.15 million years ago), a record that contains evidence of critical changes in the area's fauna, stone tools and climate, such as the disappearance of Homo habilis, a very early hominin and possible human ancestor, and the emergence of Homo erectus, a later hominin considered to be the earliest human ancestor to exit Africa and spread across Eurasia. Scientists suggest that these same beds may include evidence of the long-sought transition from the more primitive Oldowan stone tools to the appearance of the more advanced Acheulean tools. Recent research at Olduvai has focused primarily on earlier beds, so research on these later beds will likely present new data to consider. Four key previously excavated sites will be investigated through full-scale excavation.
Additional information about the Olduvai Geochronology Archaeology Project can be obtained at the project website: Olduvai Geochronology Archaeology Project .
Thanks to coldrum for the link. For more, see popular-archaeology.com
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bat400
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| New Message Posted!2013-01-15 19:53
DNA hints at African cousin to humans - Current gene profiles suggest people interbred with a now-extinct species on the continent not that long ago
Buried in the genetic blueprints of 15 people, researchers found the genetic signature of a sister species that branched off the human family tree at about the same time that Neandertals did. This lineage probably remained isolated from the one that produced modern humans for a long time, but its DNA jumped into the Homo sapiens gene pool through interbreeding with modern humans during the same era that other modern humans and Neandertals were mixing in the Middle East, researchers report in the August 3 Cell.
The evidence for ancient interbreeding is surprisingly convincing, says Richard “Ed” Green, a genome biologist (University of California, Santa Cruz). “A signal demands explanation, and archaic admixture seems to be the most reasonable one at this point,” he says.
Scientists have discovered that some people with ancestry outside Africa have DNA inherited from Neandertals or Denisovans, a mysterious group known only through DNA derived from a fossil finger bone found in a Siberian cave.
But those researchers had DNA from fossils to guide their research. This time, researchers led by Sarah Tishkoff (University of Pennsylvania, Philadelphia) didn’t have fossil DNA, or even fossils.
Tishkoff’s group took DNA donated by 15 African hunter-gatherers — five Pygmies from Cameroon and five Hadza and five Sandawe from Tanzania— and compiled complete genetic blueprints for each person. Population geneticist Joshua Akey (University of Washington) and his colleagues helped analyze the data. Using a statistical analysis, the team determined that about 2 percent of the DNA from the hunter-gatherers came from an unknown species of hominid that split from modern human ancestors about 1.1 million years ago. These long-lost human cousins must have then interbred with modern humans sometime before the common ancestral lineage of the three hunter-gatherer groups separated about 30,000 to 70,000 years ago, Akey says.
A separate study posted online July 23 on arXiv.org examined patterns of single DNA unit changes, known as SNPs, in 22 African groups. That study, by Joseph Pickrell of Harvard Medical School and colleagues, also presents evidence that some African groups, including the Hadza, may harbor DNA from unknown extinct hominids.
Other researchers aren’t convinced that the DNA remnants identified are the genetic remains of a new species of human cousin. The DNA could have come from a genetically distinct group of modern humans that has since died out due to changes in their environment, diseases or confrontations with rival groups of humans, says Jean-Jacques Hublin, (Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany.)
Relatively recent interbreeding isn’t the only explanation for the presence of this newly discovered DNA, says anthropological geneticist Paul Verdu (Stanford University). He thinks the DNA may be the genetic stamp left by a common ancestor of modern humans and another species. The DNA may have morphed so much in non-African groups, just by chance, that it is now unrecognizable.
Thanks to coldrum for the link. For more, see the article by Tina Hesman Saey: http://www.sciencenews.org/view/generic/id/342711/title/DNA_hints_at_African_cousin_to_humans
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