QuoteReplyTopic: Anthropology news updates Posted: 09-Jan-2014 at 22:59
Two Million Years Ago, Human Relative 'Nutcracker Man' Lived On Tiger Nuts
An Oxford University study has concluded that our ancient ancestors who lived in East Africa between 2.4 million-1.4 million years ago mainly ate tiger nuts (grass bulbs) supplemented with the odd grasshopper and worm.
An Oxford University study has concluded that our ancient ancestors who lived in East Africa between 2.4 million-1.4 million years ago survived mainly on a diet of tiger nuts. Tiger nuts are edible grass bulbs still eaten in parts of the world today. The study published in the journal, PLOS ONE, also suggests that these early hominins may have sought additional nourishment from fruits and invertebrates, like worms and grasshoppers.
Study author Dr Gabriele Macho examined the diet ofParanthropus boisei, nicknamed "Nutcracker Man" because of his big flat molar teeth and powerful jaws, through studying modern-day baboons in Kenya. Her findings help to explain a puzzle that has vexed archaeologists for 50 years.
Scholars have debated why this early human relative had such strong jaws, indicating a diet of hard foods like nuts, yet their teeth seemed to be made for consuming soft foods. Damage to the tooth enamel also indicated they had come into contact with an abrasive substance. Previous research using stable isotope analyses suggests the diet of these homimins was largely composed of C4 plants like grasses and sedges. However, a debate has raged over whether such high-fibre foods could ever be of sufficiently high quality for a large-brained, medium-sized hominin.
Dr Macho's study finds that baboons today eat large quantities of C4 tiger nuts, and this food would have contained sufficiently high amounts of minerals, vitamins, and the fatty acids that would have been particularly important for the hominin brain. Her finding is grounded in existing data that details the diet of year-old baboons in Amboseli National Park in Kenya -- a similar environment to that once inhabited by Paranthropus boisei. Dr Macho's study is based on the assumption that baboons intuitively select food according to their needs. She concludes that the nutritional demands of a hominin would have been quite similar.
Dr Macho modified the findings of the previous study on baboons by Stuart Altmann (1998) on how long it took the year-old baboons to dig up tiger nuts and feed on various C4 sources. She calculated the likely time taken by hominins, suggesting that it would be at least twice that of the yearling baboons once their superior manual dexterity was taken into account. Dr Macho also factored in the likely calorie intake that would be needed by a big-brained human relative.
Tiger nuts, which are rich in starches, are highly abrasive in an unheated state. Dr Macho suggests that hominins' teeth suffered abrasion and wear and tear due to these starches. The study finds that baboons' teeth have similar marks giving clues about their pattern of consumption.
In order to digest the tiger nuts and allow the enzymes in the saliva to break down the starches, the hominins would need to chew the tiger nuts for a long time. All this chewing put considerable strain on the jaws and teeth, which explains why "Nutcracker Man" had such a distinctive cranial anatomy.
The Oxford study calculates a hominin could extract sufficient nutrients from a tiger nut- based diet, i.e. around 10,000 kilojoules or 2,000 calories a day -- or 80% of their required daily calorie intake, in two and half to three hours. This fits comfortably within the foraging time of five to six hours per day typical for a large-bodied primate.
Dr Macho, from the School of Archaeology at Oxford University, said: 'I believe that the theory -- that "Nutcracker Man" lived on large amounts of tiger nuts- helps settle the debate about what our early human ancestor ate. On the basis of recent isotope results, these hominins appear to have survived on a diet of C4 foods, which suggests grasses and sedges. Yet these are not high quality foods. What this research tells us is that hominins were selective about the part of the grass that they ate, choosing the grass bulbs at the base of the grass blade as the mainstay of their diet.
'Tiger nuts, still sold in health food shops as well as being widely used for grinding down and baking in many countries, would be relatively easy to find. They also provided a good source of nourishment for a medium-sized hominin with a large brain. This is why these hominins were able to survive for around one million years because they could successfully forage -- even through periods of climatic change.'
One of the most hotly debated issues in current human origins research focuses on how the 4.4 million-year-old African species Ardipithecus ramidus is related to the human lineage. "Ardi" was an unusual primate. Though it possessed a tiny brain and a grasping big toe used for clambering in the trees, it had small, humanlike canine teeth and an upper pelvis modified for bipedal walking on the ground.
Scientists disagree about where this mixture of features positionsArdipithecus ramidus on the tree of human and ape relationships. Was Ardi an ape with a few humanlike features retained from an ancestor near in time (between 6 and 8 million years ago, according to DNA evidence) to the split between the chimpanzee and human lines? Or was it a true relative of the human line that had yet to shed many signs of its remote tree-dwelling ancestry?
New research led by Arizona State University paleoanthropologist William Kimbel confirms Ardi's close evolutionary relationship to humans. Kimbel and his collaborators turned to the underside (or base) of a beautifully preserved partial cranium of Ardi. Their study revealed a pattern of similarity that links Ardi to Australopithecus and modern humans, but not to apes.
The research appears in the Jan. 6-10 online edition ofProceedings of the National Academy of Sciences. Kimbel is director of the ASU Institute of Human Origins, a research center of the College of Liberal Arts and Sciences in the School of Human Evolution and Social Change. Joining ASU's Kimbel as co-authors are Gen Suwa (University of Tokyo Museum), Berhane Asfaw (Rift Valley Research Service, Addis Ababa), Yoel Rak (Tel Aviv University) and Tim White (University of California at Berkeley).
White's field-research team has been recovering fossil remains ofArdipithecus ramidus in the Middle Awash research area, Ethiopia since the 1990s. The most recent study of the Ardi skull, led by Suwa, was published in Science in 2009, whose work (with the Middle Awash team) first revealed humanlike aspects of its base. Kimbel co-leads the team that recovered the earliest known Australopithecus skulls from the Hadar site, home of the "Lucy" skeleton, in Ethiopia.
"Given the very tiny size of the Ardi skull, the similarity of its cranial base to a human's is astonishing," says Kimbel.
The cranial base is a valuable resource for studying phylogenetic, or natural evolutionary relationships, because its anatomical complexity and association with the brain, posture and chewing system have provided numerous opportunities for adaptive evolution over time. The human cranial base, accordingly, differs profoundly from that of apes and other primates.
In humans, the structures marking the articulation of the spine with the skull are more forwardly located than in apes, where the base is shorter from front to back and the openings on each side for passage of blood vessels and nerves are more widely separated.
These shape differences affect the way the bones are arranged on the skull base, such that it is fairly easy to tell apart even isolated fragments of ape and human basicrania.
Ardi's cranial base shows the distinguishing features that separate humans and Australopithecus from the apes. Kimbel's earlier research (with collaborator Rak) had shown that these human peculiarities were present in the earliest knownAustralopithecus skulls by 3.4 million years ago.
The new work expands the catalogue of anatomical similarities linking humans, Australopithecus and Ardipithecus on the tree of life, and shows that the human cranial base pattern is at least a million years older than Lucy's species, A. afarensis.
Paleoanthropologists generally fall into one of two camps on the cause of evolutionary changes in the human cranial base. Was it the adoption of upright posture and bipedality that caused a shift in the poise of the head on the vertebral column? If so, does the humanlike cranial base of Ar. ramidus confirm postcranial evidence for partial bipedality in this species? Or, do the changes tell us about the shape of the brain (and of the base on which it sits), perhaps an early sign of brain reorganization in the human lineage? Both alternatives will need to be re-evaluated in light of the finding that Ardi does indeed appear to be more closely related to humans than to chimpanzees.
"The Ardi cranial base fills some important gaps in our understanding of human evolution above the neck," adds Kimbel. "But it also opens up a host of new questions . . . just as it should!"
Sunlight Adaptation Region of Neanderthal Genome Found in Up to 65 Percent of Modern East Asian Population
With the Neanderthal genome now published, for the first time, scientists have a rich new resource of comparative evolution. For example, recently, scientists have shown that humans and Neanderthals once interbred, with the accumulation of elements of Neanderthal DNA found in up to 5 percent in modern humans.
Are there any advantages to the retention of Neanderthal DNA that favors modern humans? In a new article published in Molecular Biology and Evolution, authors Jin, et. al., present evidence for the accumulation of a Neanderthal DNA region found on chromosome 3 that contains 18 genes, with several related to UV-light adaptation, including the Hyal2 gene. Their results reveal this region was positively selected and enriched in East Asians, ranging from up to 49 percent in Japanese to 66 percent in Southern Chinese.
Interestingly, the authors note, the geographic distribution of the Neanderthal genomic region suggests that UV-light mutations were shown to be lost during the exodus of modern human from Africa, and reintroduced to Eurasians from Neanderthals. "Overall, it is still very controversial whether there is more Neanderthal DNA contributions to Asians than Europeans, as we have evidence to argue against this," said Lin. "Although in the case of the Hyal2 variant, it did indeed have a higher frequency in Asians."
From 45,000 years to 5,000 years before present, effective population sizes of the Neanderthal region increased at a steady rate. Notably, the growth rate of the effective population size increased at around 5,000 to 3,500 years before present, which suggests a population expansion event. This Asian-specific Neanderthal evolutionary event is also consistent with previous reports of higher levels of Neanderthal ancestry in East Asians than in Europeans.
Neanderthal Genome Shows Early Human Interbreeding, Inbreeding
Family tree of the four groups of early humans living in Eurasia 50,000 years ago and the lingering genetic heritage due to interbreeding.
The most complete sequence to date of the Neanderthal genome, using DNA extracted from a woman's toe bone that dates back 50,000 years, reveals a long history of interbreeding among at least four different types of early humans living in Europe and Asia at that time, according to University of California, Berkeley, scientists.
Population geneticist Montgomery Slatkin, graduate student Fernando Racimo and post-doctoral student Flora Jay were part of an international team of anthropologists and geneticists who generated a high-quality sequence of the Neanderthal genome and compared it with the genomes of modern humans and a recently recognized group of early humans called Denisovans.
The comparison shows that Neanderthals and Denisovans are very closely related, and that their common ancestor split off from the ancestors of modern humans about 400,000 years ago. Neanderthals and Denisovans split about 300,000 years ago.
Though Denisovans and Neanderthals eventually died out, they left behind bits of their genetic heritage because they occasionally interbred with modern humans. The research team estimates that between 1.5 and 2.1 percent of the genomes of modern non-Africans can be traced to Neanthertals.
Denisovans also left genetic traces in modern humans, though only in some Oceanic and Asian populations. The genomes of Australian aborigines, New Guineans and some Pacific Islanders are about 6 percent Denisovan genes, according to earlier studies. The new analysis finds that the genomes of Han Chinese and other mainland Asian populations, as well as of native Americans, contain about 0.2 percent Denisovan genes.
The genome comparisons also show that Denisovans interbred with a mysterious fourth group of early humans also living in Eurasia at the time. That group had split from the others more than a million years ago, and may have been the group of human ancestors known as Homo erectus, which fossils show was living in Europe and Asia a million or more years ago.
"The paper really shows that the history of humans and hominins during this period was very complicated," said Slatkin, a UC Berkeley professor of integrative biology. "There was lot of interbreeding that we know about and probably other interbreeding we haven't yet discovered."
The genome analysis will be published in the Dec. 19 issue of the journal Nature. Slatkin, Racimo and Jay are members of a large team led by former UC Berkeley post-doc Svante Pääbo, who is now at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany.
In another analysis, Jay discovered that the Neanderthal woman whose toe bone provided the DNA was highly inbred. The woman's genome indicates that she was the daughter of a very closely related mother and father who either were half-siblings who shared the same mother, an uncle and niece or aunt and nephew, a grandparent and grandchild, or double first-cousins (the offspring of two siblings who married siblings).
Further analyses suggest that the population sizes of Neanderthals and Denisovans were small and that inbreeding may have been more common in Neanderthal groups than in modern populations.
As part of the new study, Racimo was able to identify at least 87 specific genes in modern humans that are significantly different from related genes in Neanderthals and Denisovans, and that may hold clues to the behavioral differences distinguishing us from early human populations that died out.
"There is no gene we can point to and say, 'This accounts for language or some other unique feature of modern humans,'" Slatkin said. "But from this list of genes, we will learn something about the changes that occurred on the human lineage, though those changes will probably be very subtle."
According to Pääbo, the list of genes "is a catalog of genetic features that sets all modern humans apart from all other organisms, living or extinct. I believe that in it hide some of the things that made the enormous expansion of human populations and human culture and technology in the last 100,000 years possible."
The Pääbo group last year produced a high-quality Denisovan genome based on DNA from a pinky finger bone discovered in 2008 in Denisova Cave in the Altai Mountains of Southern Siberia. That bone is from a young woman who lived about 40,000 years ago. The Neanderthal toe bone was found in the same cave in 2010, though in a deeper layer of sediment that is thought to be about 10,000-20,000 years older. The cave also contains modern human artifacts, meaning that at least three groups of early humans occupied the cave at different times. The Pääbo group developed new techniques to extract DNA from these old bones.
Slatkin noted that no one is sure how long the various now-extinct groups lasted, but that there is evidence that Neanderthals and modern humans coexisted in Europe and Asia for at least 30,000 years. Interbreeding was infrequent, though how infrequent is unclear given the genomic information available today.
"We don't know if interbreeding took place once, where a group of Neanderthals got mixed in with modern humans, and it didn't happen again, or whether groups lived side by side, and there was interbreeding over a prolonged period," he said.
Ancient hand bone dates origins of human dexterity
The discovery of an ancient bone at a burial site in Kenya puts the origin of human hand dexterity more than half a million years earlier than previously thought.
In all ways, the bone - a well-preserved metacarpal that connects to the index finger - resembles that of modern man, PNAS journal reports.
It is the earliest fossilised evidence of when humans developed a strong enough grip to start using tools.
Apes lack the same anatomical features.
The 1.42 million-year-old metacarpal from an ancient hominin displays a styloid process, a distinctively human morphological feature associated with enhanced hand function.
Its discovery provides evidence for the evolution of the modern human hand more than 600,000 years earlier than previously documented and probably in the times of the genus Homo erectussensu lato.
The styloid process helps the hand bone lock into the wrist bones, allowing for greater amounts of pressure to be applied to the wrist and hand from a grasping thumb and fingers.
Prof Carol Ward and her colleagues note that a lack of the styloid process created challenges for apes and earlier humans when they attempted to make and use tools.
This lack of a styloid process may have increased the chances of having arthritis earlier.
Prof Ward, professor of pathology and anatomical sciences at the University of Missouri, Columbia, said: "The styloid process reflects an increased dexterity that allowed early human species to use powerful yet precise grips when manipulating objects.
"This was something that their predecessors couldn't do as well due to the lack of this styloid process and its associated anatomy.
"With this discovery, we are closing the gap on the evolutionary history of the human hand. This may not be the first appearance of the modern human hand, but we believe that it is close to the origin, given that we do not see this anatomy in any human fossils older than 1.8 million years.
"Our specialised, dexterous hands have been with us for most of the evolutionary history of our genus, Homo. They are - and have been for almost 1.5 million years - fundamental to our survival," she said.
The bone was found at the Kaitio site in West Turkana, near an area where the earliest Acheulian tools have appeared. Acheulian tools are ancient, shaped stone tools that include stone hand axes more than 1.6 million years old.
Ancient Gem-Studded Teeth Show Skill of Early Dentists
"...May 18, 2009—The glittering "grills" of some hip-hop stars
aren't exactly unprecedented. Sophisticated dentistry allowed Native
Americans to add bling to their teeth as far back as 2,500 years ago, a
new study says.
Ancient peoples of southern North America went to "dentists"—among the
earliest known—to beautify their chompers with notches, grooves, and
semiprecious gems, according to a recent analysis of thousands of teeth
examined from collections in Mexico's National Institute of Anthropology
and History (such as the skull above, found in Chiapas, Mexico).
Scientists don't know the origin of most of the teeth in the
collections, which belonged to people living throughout the region,
called Mesoamerica, before the Spanish conquests of the 1500s.
Nutrients in food vital to location of early human settlements: The original 'Palaeo-diet'
Research led by the University of Southampton has found that early humans were driven by a need for nutrient-rich food to select 'special places' in northern Europe as their main habitat. Evidence of their activity at these sites comes in the form of hundreds of stone tools, including handaxes.
A study led by physical geographer at Southampton Professor Tony Brown, in collaboration with archaeologist Dr Laura Basell at Queen's University Belfast, has found that sites popular with our early human ancestors, were abundant in foods containing nutrients vital for a balanced diet. The most important sites, dating between 500,000 to 100,000 years ago were based at the lower end of river valleys, providing ideal bases for early hominins – early humans who lived before Homo sapiens (us).
Professor Brown says: "Our research suggests that floodplain zones closer to the mouth of a river provided the ideal place for hominin activity, rather than forested slopes, plateaus or estuaries. The landscape in these locations tended to be richer in the nutrients critical for maintaining population health and maximising reproductive success."
The project was funded by English Heritage and the University of Southampton's Faculty of Social and Human Sciences. It involved academics from Geography and Environment and Medicine at Southampton, together with Archaeology at Queen's.
The researchers began by identifying Palaeolithic sites in southern England and northern France where high concentrations of handaxes had been excavated –for example at Dunbridge in Hampshire, Swanscombe near Dartford and the Somme Valley in France. They found there were fewer than 25 sites where 500 handaxes or more were discovered. The high concentration of these artefacts suggests significant activity at the sites and that they were regularly used by early hominins.
Professor Brown and his colleagues then compiled a database of plants and animals known to exist in the Pleistocene epoch (a period between 2.6 million to 11,700 years ago) to establish a potential list of nutrient resources in the landscape and an estimation of the possible diet. This showed that an abundance of nutritious foods were available and suggests this was likely to have been the dominant factor driving early humans to focus on these sites in the lower reaches of river valleys, close to the upper tidal limit of rivers.
Over 50 nutrients are needed to sustain human life. In particular, it would have been essential for early humans to find sources of protein, fats, carbohydrates, folic acid and vitamin C. The researchers suggest vitamins and protein may have come from sources such as raw liver, eggs, fish and plants, including watercress (which grows year round). Fats in particular, may have come from bone marrow, beaver tails and highly nutritious eels.
The nutritional diversity of these sites allowed hominins to colonise the Atlantic fringe of north west Europe during warm periods of the Pleistocene. These sites permitted the repeated occupation of this marginal area from warmer climate zones further south
Professor Brown comments: "We can speculate that these types of locations were seen as 'healthy' or 'good' places to live which hominins revisited on a regular basis. If this is the case, the sites may have provided 'nodal points' or base camps along nutrient-rich route-ways through the Palaeolithic landscape, allowing early humans to explore northwards to more challenging environments."
City living in ancient Rome "...The higher floors, where rent was paid by the day or week, were cramped,
often with only one room to a family. A family lived in constant fear
of eviction. They had no access to natural light, were hot in the summer
and cold in the winter with little or no running water - this even
meant a latrina or toilet. While the city’s first sewer system
or Cloaca Maxima had appeared in the six century BCE, it did not benefit
those on the upper floors (lower floors had access to running water and
indoor toilets). Refuse, even human waste, was routinely dumped onto
the streets, not only causing a terrible stench but a breeding ground
for disease. For many, the only alternative was to use the public
toilets. Combine the lack of street lights (there was no foot traffic at
night due to the high crime rate), the decaying buildings, and the fear
of fire, life on the upper floors of the tenements was not very
enjoyable for many of the poor..." http://www.ancient.eu.com/article/637/
Acupuncture in the Ice Age "... Ötzi is covered with more than 50 tattoos in the form of lines and
crosses made up of small incisions in his skin into which charcoal was
rubbed. Because they are all found on parts of the body that show
evidence of a lifetime of wear and tear—the ankles, wrists, knees,
Achilles tendon, and lower back, for example—it’s thought that Ötzi’s
tattoos were therapeutic, not decorative or symbolic. When Ötzi was
first studied, archaeologists were shocked because they had never before
seen Copper Age tattoos, and because acupuncture as a treatment for
joint distress, rheumatism, and arthritis was thought to have originated
in Asia more than 2,000 years later...." http://archaeology.org/issues/109-1311/features/tattoos/1351-oetzi-copper-age-alps-iceman-tattoos
Partial skeleton suggests ruggedly built, tree-climbing human ancestor
A human ancestor characterized by “robust” jaw and skull bones was a muscular creature with a gorilla-like upper body and more adaptive to its environment than previously thought, scientists have discovered.
Researchers found a partial skeleton — including arm, hand, leg and foot fragments — dated to 1.34 million years old and belonging to Paranthropus boiseiat the Olduvai Gorge World Heritage fossil site in Tanzania. The find, published in the latest edition of the scientific journal PLOS ONE, represents one of the most recent occurrences of P. boisei before its extinction in East Africa.
“This is the first time we’ve found bones that suggest that this creature was more ruggedly built — combining terrestrial bipedal locomotion and some arboreal behaviors — than we’d previously thought,” said Charles Musiba, Ph.D., associate professor of anthropology at the University of Colorado Denver, part of the international research team. “It seems to have more well-formed forearm muscles that were used for climbing, fine-manipulation and all sorts of behavior.”
While P. boisei was known for its massive jaws and cranium — anthropologist Mary Leakey discovered the first skull in 1959 in northern Tanzania — the build and skeletal adaptations of the rest of the archaic hominin’s body have been unknown until recently.
During excavations at Olduvai in 2010-2011, the team discovered the partial skeleton of a large adult individual who is represented by various teeth and skeletal parts. Other team members are Manuel Dominguez-Rodrigo, Ph.D., professor of anthropology and prehistory at Complutense University, Madrid; Audax Mabulla, Ph.D., associate professor of archaeology, University of Dar es Salaam, Tanzania, Gail Ashley, Ph.D., professor of geological sciences, Rutgers University; David Uribelarrea, Ph.D. a professor of geology at Complutense University of Madrid; Henry Bunn, Ph.D., professor of anthropology, University of Wisconsin-Madison; and Travis Pickering, Ph.D., professor of anthropology, University of Wisconsin-Madison.
P. boisei was a long-lived species of archaic hominin that first evolved in East Africa about 2.3 million years ago. In the absence of evidence of other skeletal remains, it was commonly assumed that the skeleton of P. boiseiwas like that of more ancient species of the genus Australopithecus, from which P. boisei likely evolved.
“We are starting to understand the physiology of these individuals of this particular species and how it actually adapted to the kind of habitat it lived in,” Musiba said. “We knew about the kind of food it ate — it was omnivorous, leaning more toward plant material — but now we know more: how it walked around and now we know it was a tree climber.”
The size of the arm bones suggests strong forearms and a powerful upper body. “It’s a different branch on our ancestry tree,” Musiba said. “It came later than the other hominins, so the question now is ‘what happened to it?’ We’re going to do more work on biomechanics and see what else this creature was doing.”
He noted that the creature likely stood 3.5 to 4.5 feet tall and possessed a robust frame. “We know that it was very strong,” Musiba said. “It’s unprecedented to find how strong this individual was. The stronger you are the more adaptive you are.”
In summer 2014, the bones will be displayed as part of a large exhibit on human origins in Dar es Salaam, Tanzania. The joint-museum exhibit involves the Museum of Human Evolution in Burgos, Spain, the Regional Museum of Archaeology in Madrid, and the National Museum of Dar es Salaam.
With each find scientists are adding to the understanding of how humans evolved and adapted to their surroundings through time. “The more we are finding of these fossils, the more we are learning about the history of these species,” Musiba said.
Matthias Meyer and his team from the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, have developed new techniques for retrieving and sequencing highly degraded ancient DNA. They then joined forces with Juan-Luis Arsuaga and applied the new techniques to a cave bear from the Sima de los Huesos site. After this success, the researchers sampled two grams of bone powder from a hominin thigh bone from the cave. They extracted its DNA and sequenced the genome of the mitochondria or mtDNA, a small part of the genome that is passed down along the maternal line and occurs in many copies per cell. The researchers then compared this ancient mitochondrial DNA with Neandertals, Denisovans, present-day humans, and apes.
From the missing mutations in the old DNA sequences the researchers calculated that the Sima hominin lived about 400,000 years ago. They also found that it shared a common ancestor with the Denisovans, an extinct archaic group from Asia related to the Neandertals, about 700,000 years ago. “The fact that the mtDNA of the Sima de los Huesos hominin shares a common ancestor with Denisovan rather than Neandertal mtDNAs is unexpected since its skeletal remains carry Neandertal-derived features”, says Matthias Meyer. Considering their age and Neandertal-like features, the Sima hominins were likely related to the population ancestral to both Neandertals and Denisovans. Another possibility is that gene flow from yet another group of hominins brought the Denisova-like mtDNA into the Sima hominins or their ancestors.
The Neaderthals organized their homes like we do... "...The findings, published in the latest edition of the Canadian Journal of Archaeology, indicate that Neanderthals butchered animals, made tools and gathered round the fire in different parts of their shelters.
“There has been this idea that Neanderthals did not have an organized
use of space, something that has always been attributed to humans,”
said Julien Riel-Salvatore, assistant professor of anthropology at the
University of Colorado Denver and lead author of the study. “But we
found that Neanderthals did not just throw their stuff everywhere but in
fact were organized and purposeful when it came to domestic space.”..."
DNA FROM 400,000 YEAR OLD HOMININ: A GREAT LEAP FORWARD
Homo heidelbergensis skull from Sima de los Huesos.
Using novel techniques to extract and study ancient DNA researchers at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, have determined an almost complete mitochondrial genome sequence of a 400,000-year-old representative of the genus Homo from Sima de los Huesos, a unique cave site in Northern Spain, and found that it is related to the mitochondrial genome of Denisovans, extinct relatives of Neanderthals in Asia. DNA this old has until recently been retrieved only from the permafrost.
Unique hominins
Sima de los Huesos, the “bone pit”, is a cave site in Northern Spain that has yielded the world’s largest assembly of Middle Pleistocene hominin fossils, consisting of at least 28 skeletons, which have been excavated and pieced together over the course of more than two decades by a Spanish team of paleontologists led by Juan-Luis Arsuaga. The fossils are classified as Homo heidelbergensis but also carry traits typical of Neanderthals. Until now it had not been possible to study the DNA of these unique hominins.
Matthias Meyer and his team from the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, have developed new techniques for retrieving and sequencing highly degraded ancient DNA. They then joined forces with Juan-Luis Arsuaga and applied the new techniques to a cave bear from the Sima de los Huesos site. After this success, the researchers sampled two grams of bone powder from a hominin thigh bone from the cave. They extracted its DNA and sequenced the genome of the mitochondria or mtDNA, a small part of the genome that is passed down along the maternal line and occurs in many copies per cell. The researchers then compared this ancient mitochondrial DNA with Neanderthals, Denisovans, present-day humans, and apes.
Common ancestor?
From the missing mutations in the old DNA sequences the researchers calculated that the Sima hominin lived about 400,000 years ago. They also found that it shared a common ancestor with the Denisovans, an extinct archaic group from Asia related to the Neanderthals, about 700,000 years ago. “The fact that the mtDNA of the Sima de los Huesos hominin shares a common ancestor with Denisovan rather than Neanderthal mtDNAs is unexpected since its skeletal remains carry Neanderthal-derived features”, says Matthias Meyer. Considering their age and Neanderthal-like features, the Sima hominins were likely related to the population ancestral to both Neanderthals and Denisovans. Another possibility is that gene flow from yet another group of hominins brought the Denisova-like mtDNA into the Sima hominins or their ancestors.
Complex pattern
“Our results show that we can now study DNA from human ancestors that are hundreds of thousands of years old. This opens prospects to study the genes of the ancestors of Neanderthals and Denisovans. It is tremendously exciting” says Svante Pääbo, director at the Max Planck Institute for Evolutionary Anthropology.
“This unexpected result points to a complex pattern of evolution in the origin of Neanderthals and modern humans. I hope that more research will help clarify the genetic relationships of the hominins from Sima de los Huesos to Neanderthals and Denisovans” says Juan-Luis Arsuaga, director of the Center for Research on Human Evolution and Behaviour. The researchers are now pursuing this goal by focusing on retrieving DNA from more individuals from this site and on retrieving also nuclear DNA sequences.
Ancient Siberian genome reveals genetic origins of Native-Americans
The genome sequence of a 24,000-year-old Siberian individual has provided a key piece of the puzzle in the quest for Native American origins. The ancient Siberian demonstrates genomic signatures that are basal to present-day western Eurasians and close to modern Native Americans. This surprising finding has great consequences for our understanding of how and from where ancestral Native Americans descended, and also of the genetic landscape of Eurasia 24,000 years ago. The breakthrough is reported in this week'sNature(Advance Online Publication) by an international team of scientists, led by the Centre for GeoGenetics at the Natural History Museum of Denmark (University of Copenhagen).
The search for Native American ancestors has been focused in northeastern Eurasia. In late 2009, researchers sampled at the Hermitage Museum, St. Petersburg the remains of a juvenile individual (MA-1) from the Upper Palaeolithic site of Mal'ta in south-central Siberia. The MA-1 individual dated to approximately 24,000 years ago. Now, the team reports genomic results from the MA-1 individual which unravel the origins of the First Americans – ancestors of modern-day Native Americans.
"Representing the oldest anatomically modern human genome reported thus far, the MA-1 individual has provided us with a unique window into the genetic landscape of Siberia some 24,000 years ago", says Dr. Maanasa Raghavan from the Centre for GeoGenetics and one of the lead authors of the study. "Interestingly, the MA-1 individual shows little to no genetic affinity to modern populations from the region from where he originated - south Siberia."
Instead, both the mitochondrial and nuclear genomes of MA-1 indicate that he was related to modern-day western Eurasians. This result paints a picture of Eurasia 24,000 years ago which is quite different from the present-day context. The genome of MA-1 indicates that prehistoric populations related to modern western Eurasians occupied a wider geographical range into northeast Eurasia than they do today.
Dual ancestry of Native Americans
The most significant finding that the MA-1 genome reveals is its relation to modern Native Americans. This relative of present-day western Eurasians shows close affinity to modern Native Americans, but surprisingly not to East Asians who are regarded as being genetically closely related to Native Americans.
Furthermore, the team finds evidence that this genetic affinity between MA-1 and Native Americans is mediated by a gene flow event from MA-1 into the First Americans, which can explain between 14-38% of the ancestry of modern Native Americans, with the remainder of the ancestry being derived from East Asians. Supported by numerous reasons against these signatures being caused by contamination from modern DNA sources or from post-Columbian admixture (post 1492 AD), the study concludes that two distinct Old World populations led to the formation of the First American gene pool: one related to modern-day East Asians, and the other a Siberian Upper Palaeolithic population related to modern-day western Eurasians.
"The result came as a complete surprise to us. Who would have thought that present-day Native Americans, who we learned in school derive from East Asians, share recent evolutionary history with contemporary western Eurasians? Even more intriguingly, this happened by gene flow from an ancient population that is so far represented only by the MA-1 individual living some 24,000 years ago", says Professor Eske Willerslev from the Centre for GeoGenetics who led the study.
Early cosmopolitans
Additionally, results from a second south-central Siberian from Afontova Gora-2 site are presented in order to address human occupation of the region during and after the Last Glacial Maximum (LGM; ca. 26,000 to 19,000 years ago), a climatically cold period when glacial ice sheets extended to their maximum range. At approximately 17,000 years ago, this post-LGM individual demonstrates similar genomic signatures as MA-1, with close affinity to modern western Eurasians and Native Americans and none to present-day East Asians. This result indicates that genetic continuity persisted in south-central Siberia throughout this climatically harsh period, which is a significant consideration for the peopling of Beringia, and eventually the Americas some 15,000 years ago.
Dr. Pontus Skoglund from Uppsala University, and one of the lead authors of the study, explains, "Most scientists have believed that Native American lineages go back about 14,000 years ago, when the first people crossed Beringia into the New World. Our results provide direct evidence that some of the ancestry that characterizes Native Americans is at least 10,000 years older than that, and was already present in Siberia before the last Ice Age."
Professor Kelly Graf from the Center for the Study of the First Americans (Texas A&M University), who together with Professor Willerslev did the sampling, adds, "Our findings are significant at two levels. First, it shows that Upper Paleolithic Siberians came from a cosmopolitan population of early modern humans that spread out of Africa to Europe and Central and South Asia. Second, Paleoindian skeletons with phenotypic traits atypical of modern-day Native Americans can be explained as having a direct historical connection to Upper Paleolithic Siberia."
As such, results from this study contribute a major leap forward for resolving the peopling of the Americas.
In a further study of Neanderthal occupation at Abri du Maras, Ardèche in France, the evidence is stacking up to support the view that this group was behaviourally flexible and capable of creating a variety of sophisticated tools including projectile points and more importantly, cord and string.
Fibrous materials that can be used to create cords are difficult to find in the archaeological record and have usually rotted away, so the oldest known string dated back only 30,000 years. However, perforations in small stone and tooth artefacts as well as shells from other Neanderthal sites in France suggested the pieces had once been threaded on string and worn as pendants.
Bruce Hardy at Kenyon College in Gambier, Ohio, explains that “The wear patterns provide circumstantial evidence of early use of string, but the evidence is not definitive.” These items could also have been threaded onto animal sinew.
90,000 years ago
A new article in the journal Quaternary Science Reviews examines much of the material recovered from the Abri du Maras site and appears to provide compelling evidence that twisted fibres were being created by Neanderthals at least 90,000 years ago.
At this site, Neanderthals also exploited a wide range of resources including large mammals, fish, ducks, raptors, rabbits, mushrooms, plants and wood.
However, Hardy and his colleagues have found slender, 0.7-millimetre-long plant fibres that are twisted together and were found near to some stone artefacts. Such fibres are not twisted together in nature, says the team, suggesting that the Neanderthals were responsible.
Experiments
As these fibres are not twisted in their natural state experiments were carried out involving incising, planing, whittling, scraping and boring. In all cases, no twisted fibres resulted.
Further experiments conducted by Bruce Hardy involved the scraping, cutting and slicing of a variety of non-woody plants (roots, tubers, reeds, etc.), and again these also produced no twisted fibres such as those observed.
While not definitive, the lack of twisted fibres in these experiments lends some credence to the hypothesis that these derive from cordage.
“If they are indeed remnants of string or cordage, then they would be the earliest direct evidence of string,” says Hardy. “Albeit very fragmentary evidence.”
This in turn suggests that the Neanderthals occupying the Abri du Maras site had learned the complex act of making and using cordage, rather than imitating modern humans. The uses and potential of this material has greater implications for understanding Neanderthal behaviour.
A number of sophisticated behaviours
In fact, a growing body of evidence suggests Neanderthals developed a number of sophisticated behaviours.
Stone tools created by Neanderthals have also been found on the Greek islands of Lefkada, Kefalonia and Zakynthos, hinting that the species may have made and used boats to cross the sea – although no direct evidence of boats has been found so far.
To carry out such voyages sturdy ropes would have been required to build and use rafts or boats. “The ability of Neanderthals to manufacture string and cordage certainly does make the idea of Neanderthal seafaring more plausible,” Bruce Hardy says.
Fossil Fragments of Unknown Early Human Come Together
Scientists at a cave site in South Africa are kicking into high gear as they continue to uncover more fossil bones of what is suspected to be an early human ancestral ("hominid") species.
The location is known as the "Rising Star" Cave site in South Africa's Cradle of Humankind World Heritage Site, about 40 kilometers north of Johannesburg, and although it is far too soon to determine the classification and age of the fossil finds, the site could turn out to yield the richest collection of hominid fossil finds at any one site in South Africa, a country that has made history in the chronicles of human evolution research. More than 300 fossil fragments of multiple individuals have been recovered, with potentially much more to come. In the world of early human fossil hunting, this is a rare occurrence.
“Even [for] the best known species of early hominid, there are pieces missing,” said University of the Witwatersrand paleoanthropologist Lee Berger in a blog report from National Geographic reporter Andrew Howley. “What is exceptional about these fossils is we already have parts of the anatomy that have almost never been seen before in any species, and certainly not in this kind of abundance.”*
And now, one of the most critical tasks of the expedition begins to unfold -- the assembly and examination of key fragments of the expedition's first-recovered fossil cranium, an exercise that will lend some of the first important clues to the identity of the early human who inhabited the area of the cave eons ago. Back in the tent lab near the site, Darryl de Ruiter of Texas A & M University and the Evolutionary Studies Institute will do the honors. According to de Ruiter, it is arguably the cranium that retains the most overall consistency among early human species, as other parts, such as the mandible (jaw bone), may vary considerably in size and shape, even within a species.
The fragile cranium fragments had to be slowly and carefully excavated and then removed from their cave context before much further work could be done to excavate what could lie beneath. Now that they have been removed, excavations will progress full-speed ahead to recover what could be many more finds.
The trove of bones were first discovered in October by a pair of recreational cavers, who alerted Lee Berger, a well-known paleoanthropologist with the University of Witwatersrand, who has been at the forefront of major hominid fossil discoveries in South Africa, such as the recent Australopithecus sedibafinds at the Malapa cave site. To investigate the cave and its contents, Berger spearheaded the assembly of an expeditionary group (called the "Rising Star Expedition") of scientists. Along with chief scientists, the group included six researchers who were hand-picked to actually enter the cave system to excavate and remove the fossil bones. To qualify for this job, these team members had to have a master's degree or Ph.D. in paleontology, archaeology or a related field; they had to be experienced spelunkers, or cavers; and they had to be small enough to successfully and safely negotiate an 18-centimeter-wide opening leading to the targeted cave chamber. The effort has to date proven to be a great success.
So, human evolution happened in Africa because of the drastic climate changes caused by the plate tectonics, that hit most dramatically in North/West Africa
How Climate Change and Plate Tectonics Shaped Human Evolution
"...We have now started to put together a coherent picture of how the changing East African landscape has driven human evolution over the last ten million years. The region has altered beyond all recognition, from flat and forested to one filled with spectacular, two-mile-high mountains, savannahs and tropical forests. By priming the land to form lake basins that were sensitive to small changes in rainfall, extreme climate pulses of alternately arid and wet period occurred and had a profound effect on all the animals living in East Africa. The powerful forces of plate tectonics and climate variability ultimately led to our hominid ancestors' development and their dispersal from Africa, to the Caucasus, the Fertile Crescent, and ultimately the rest of the world...."
http://www.scientificamerican.com/article.cfm?id=how-climate-change-and-plate-tectonics-shaped-human-evolution&page=2
Ancient, Modern DNA Tell Story of First Humans in the Americas
Anthropology professor Ripan Malhi works with Native Americans to collect and analyze their DNA and that of their ancestors.
University of Illinois anthropology professor Ripan Malhi looks to DNA to tell the story of how ancient humans first came to the Americas and what happened to them once they were here.
He will share some of his findings at the meeting, "Ancient DNA: The First Three Decades," at The Royal Society in London on Nov. 18 and 19.
Malhi, an affiliate of the Institute for Genomic Biology at Illinois, will describe his collaborative approach, which includes working with present-day Native Americans on studies of their genetic history.
He and a group of collaborators from the Tsimshian Nation on the northwest coast of British Columbia, for example, recently found a direct ancestral link between ancient human remains in the Prince Rupert Island area and the native peoples living in the region today. That study looked at changes in the mitochondrial genome, which children inherit only from their mothers.
Other studies from Malhi's lab analyze changes in the Y chromosome or the protein-coding regions of the genome.
"The best opportunity to infer the evolutionary history of Native Americans and to assess the effects of European colonization is to analyze genomes of ancient Native Americans and those of their living descendants," Malhi said.
"I think what makes my lab unique is that we focus not only on the initial peopling of the Americas but also what happened after the initial peopling. How did these groups move to new environments and adapt to their local settings over 15,000 years?"
While continuing his work in British Columbia, Malhi also is setting up study sites in California, Guatemala, Mexico and Illinois.
"What's interesting about the northwest coast and California is that these communities were complex hunter-gatherer societies, whereas in Mexico and Guatemala, it's more communities that transitioned to farming and then experienced the effects of European colonization," he said.
Genomic studies can fill in the blanks on studies that seek to tell the story of life in the Americas before and after European colonization, Malhi said. Researchers may draw the wrong conclusions about human history when looking only at artifacts and language, he said.
A dissertation on relationships between the Papacy and Jews in 12 century Rome. The link gives a PDF with the full text.
"...Relationships are based on opinions and attitudes, beliefs and perceptions. These facets of the relationship between Christians and Jews have varied in character, value, and intensity over the centuries since the inception of the movement within Judaism by followers of Jesus Christ. As Christianity grew and developed doctrinally into a religious system separate from Judaism, attitudes voiced by Church leaders, and particularly by the papacy, often determined the nature of the relationship between Christians and Jews, reinforcing or promoting popular perceptions and beliefs...."
http://www.medievalists.net/2010/08/16/the-relationship-between-the-papacy-and-the-jews-in-twelfth-century-rome-papal-attitudes-toward-biblical-judaism-and-contemporary-european-jewry/
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