1.PAPUA NEW GUINEA - SYDNEY (AFP).- A 6,000-year-old skull found in Papua New Guinea is likely the world's oldest-known tsunami victim, experts said Thursday after a new analysis of the area it was found in.
The partially preserved Aitape Skull was discovered in 1929 by Australian geologist Paul Hossfeld, 12 kilometres (seven miles) inland from the northern coast of the Pacific nation.
It was long thought to belong to Homo erectus (upright man), an extinct species thought to be an ancestor of the modern human that died out some 140,000 years ago.
But more recent radiocarbon dating estimated it was closer to 6,000 years old, making it a member of our own species -- Homo sapiens. At that time, sea levels were higher and the area would have been near the coast.
An international team led by the University of New South Wales returned to the site to collect the same geological deposits observed by Hossfeld.
Back in the lab, they studied details of the sediment including its grain size and geochemical composition, which can help identify a tsunami inundation.
They also identified a range of microscopic organisms from the ocean in the sediment, similar to those found in soil after a devastating tsunami hit the region in 1998.
"We have discovered that the place where the Aitape Skull was unearthed was a coastal lagoon that was inundated by a large tsunami about 6,000 years ago," said study author and UNSW scientist James Goff.
"It was similar to the one that struck nearby with such devastating effect in 1998, killing more than 2,000 people.
"We conclude that this person who died there so long ago is probably the oldest-known tsunami victim in the world."
The conclusions, aided by researchers from the United States, France, New Zealand and Papua New Guinea, are published in the journal PLOS ONE.
Goff, a world authority on tsunamis, said while the bones of the skull had been well-studied previously, little attention had been paid to the sediments where they were unearthed.
"The geological similarities between these sediments and the sediments laid down during the 1998 tsunami made us realise that human populations in this area have been affected by these massive inundations for thousands of years," he said.
"After considering a range of possible scenarios, we believe that, on the balance of the evidence, the individual was either killed directly in the tsunami, or was buried just before it hit and the remains were redeposited."
Following the 1998 tsunami, which penetrated up to five kilometres inland, attempts to retrieve victims were called off after a week because crocodiles were feeding on the corpses, leading to their dismemberment.
This may also explain why the skull of the person who died 6,000 years ago was found on its own, without any other bones, the researchers said.
World attention has been drawn to the devastating impact of tsunamis in recent decades, particularly following those in Indonesia in 2004 and Japan in 2011, which killed about 230,000 and 16,000 people respectively.
But research in the Pacific has shown that throughout history and prehistory, the region has seen repeated catastrophic tsunamis that have caused death, abandonment of settlements, breakdown of trading routes and even war, the study said.
"This work reinforces a growing recognition that tsunamis have had a significant influence on coastal populations throughout Pacific prehistory and doubtless elsewhere as well," said study co-author Darren Curnoe, also from UNSW.
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2. PARIS (AFP).- The skull of an infant ape buried by a volcano 13 million years ago has preserved intriguing clues about the ancestor humans shared with apes -- including a likely African origin, scientists said Wednesday.
A previously-unknown creature that shared an extended family with the human forefather, had a flat face like that of our far-flung cousin the gibbon, but did not move like one, its discoverers wrote in the journal Nature.
They named it Nyanzapithecus alesi after "ales" -- the word for "ancestor" in the Turkana language of Kenya, where the lemon-sized skull was unearthed.
The sole specimen is that of an infant that would have grown to weigh about 11 kilogrammes (24 pounds) in adulthood. It had a brain much larger than monkeys from the same epoch, the researchers said.
"If you compare to all living things, it looks most like a gibbon," study co-author Isaiah Nengo of the Stony Brook University in New York told AFP.
This does not mean the direct ancestor of living apes necessarily looked like a gibbon, just that a member of its family did at the time.
Assuming a gibbon-like appearance for our ancestor would be similar to scientists from the future unearthing a gorilla skull and concluding that all hominins -- the group that also includes chimps and humans -- looked like a gorilla.
The location of the extraordinary fossil find, said the team, supported the idea that the ape-human ancestor lived in Africa and not in Asia as some have speculated.
"With this we... put the root of the hominoidea in Africa more firmly," said Nengo.
Hominoidea, or hominoids, is the name for the family of apes.
The group is divided in two, with humans, bonobos, chimps, gorillas and orangutans on the one side (hominids), and agile, tree-swinging gibbons (hylobatids) alone on the other.
The new species belonged to a much older, ancestral group that included the forefather of hominoids, the researchers concluded.
Out of Africa
That group, which has no official name yet, lived and died millions of years ago.
"The majority of that group, and the oldest members of that group, are African but we would not have been able to resolve all of that without Alesi," said Nengo.
"Alesi is the one that has allowed us to... know who is in that group... and when we take a close look we see that most of the group are found in Africa."
Alesi's is the most complete ape skull from the entire Miocene period, which ranged from about 24 million to five million years ago.
"It may be younger (than some other fossil pieces) but it is the only one where you have a face, you have the base of a skull, you have the inside of the skull, so you can see what a representative of them might have looked like," said Nengo.
Hi-tech scans of the skull showed that Alesi had teeth similar to some gibbon species.
While its baby teeth had been knocked out, Alesi's adult teeth lay unerupted inside its jaw, and their age could be determined with great precision -- the ape was one year and four months old when it died.
The team also established that the balance organs in Alesi's ear were unlike those of the gibbon, meaning it probably had a different, slower, way of moving.
While a lot is known about human evolution since we split from chimps about seven million years ago, little was known about common ancestors from before 10 million years ago.
Commenting on the study, anthropologist Brenda Benefit of the New Mexico State University described this as a fossil find "that I never thought would be made during my lifetime".
"This discovery will help to fill in missing information regarding adaptations that influence ape and human evolutionary histories," she said in comments published by the journal.
"This is an exceptional discovery," agreed Paul Tafforeau of the European Synchrotron Radiation Facility in Grenoble, France, who helped examine the skull. http://artdaily.com/news/98130/Ancient-skull-hints-at-African-roots-for-ape-human-ancestor--Study#.WdZ690qGMnY
3. COPENHAGEN.- Early humans seem to have recognised the dangers of inbreeding at least 34,000 years ago, and developed surprisingly sophisticated social and mating networks to avoid it, new research has found.
The study, reported in the journal Science, examined genetic information from the remains of anatomically modern humans who lived during the Upper Palaeolithic, a period when modern humans from Africa first colonised western Eurasia. The results suggest that people deliberately sought partners beyond their immediate family, and that they were probably connected to a wider network of groups from within which mates were chosen, in order to avoid becoming inbred.
This suggests that our distant ancestors are likely to have been aware of the dangers of inbreeding, and purposely avoided it at a surprisingly early stage in prehistory.
The symbolism, complexity and time invested in the objects and jewellery found buried with the remains also suggests that it is possible that they developed rules, ceremonies and rituals to accompany the exchange of mates between groups, which perhaps foreshadowed modern marriage ceremonies, and may have been similar to those still practised by hunter-gatherer communities in parts of the world today.
The study’s authors also hint that the early development of more complex mating systems may at least partly explain why anatomically modern humans proved successful while other species, such as Neanderthals, did not. However, more ancient genomic information from both early humans and Neanderthals is needed to test this idea.
The research was carried out by an international team of academics, led by the University of Cambridge, UK, and the University of Copenhagen, Denmark. They sequenced the genomes of four individuals from Sunghir, a famous Upper Palaeolithic site in Russia, which is believed to have been inhabited about 34,000 years ago.
The human fossils buried at Sunghir represent a rare and highly valuable, source of information because very unusually for finds from this period, the people buried there appear to have lived at the same time and were buried together. To the researchers’ surprise, however, these individuals were not closely related in genetic terms; at the very most, they were second cousins. This is true even in the case of two children who were buried head-to-head in the same grave.
Professor Eske Willerslev, who holds posts both as a Fellow at St John’s College, Cambridge, and at the University of Copenhagen, was the senior author on the study.
• What this means is that even people in the Upper Palaeolithic, who were living in tiny groups, understood the importance of avoiding inbreeding, he said.
• The data that we have suggest that it was being purposely avoided.
• This means that they must have developed a system for this purpose. If small hunter–gatherer bands were mixing at random, we would see much greater evidence of inbreeding than we have here.
Early humans and other hominins such as Neanderthals appear to have lived in small family units. The small population size made inbreeding likely, but among anatomically modern humans it eventually ceased to be commonplace; when this happened, however, is unclear.
• Small family bands are likely to have interconnected with larger networks, facilitating the exchange of people between groups in order to maintain diversity, Professor Martin Sikora, from the Centre for GeoGenetics at the University of Copenhagen, said.
Sunghir contains the burials of one adult male and two younger individuals, accompanied by the symbolically-modified incomplete remains of another adult, as well as a spectacular array of grave goods. The researchers were able to sequence the complete genomes of the four individuals, all of whom were probably living on the site at the same time. These data were compared with information from a large number of both modern and ancient human genomes.
They found that the four individuals studied were genetically no closer than second cousins, while an adult femur filled with red ochre found in the children’s’ grave would have belonged to an individual no closer than great-great grandfather of the boys.
• This goes against what many would have predicted, Willerslev said.
• I think many researchers had assumed that the people of Sunghir were very closely related, especially the two youngsters from the same grave.
The people at Sunghir may have been part of a network similar to that of modern day hunter-gatherers, such as Aboriginal Australians and some historical Native American societies. Like their Upper Palaeolithic ancestors, these people live in fairly small groups of around 25 people, but they are also less directly connected to a larger community of perhaps 200 people, within which there are rules governing with whom individuals can form partnerships.
• Most non-human primate societies are organised around single-sex kin where one of the sexes remains resident and the other migrates to another group, minimising inbreeding says Professor Marta Mirazón Lahr, from the Leverhulme Centre for Human Evolutionary Studies at the University of Cambridge.
• At some point, early human societies changed their mating system into one in which a large number of the individuals that form small hunter-gatherer units are non-kin. The results from Sunghir show that Upper Palaeolithic human groups could use sophisticated cultural systems to sustain very small group sizes by embedding them in a wide social network of other groups.
By comparison, genomic sequencing of a Neanderthal individual from the Altai Mountains who lived around 50,000 years ago indicates that inbreeding was not avoided. This leads the researchers to speculate that an early, systematic approach to preventing inbreeding may have helped anatomically modern humans to thrive, compared with other hominins.
This should be treated with caution, however:
• We don’t know why the Altai Neanderthal groups were inbred, Sikora said.
• Maybe they were isolated and that was the only option; or maybe they really did fail to develop an available network of connections. We will need more genomic data of diverse Neanderthal populations to be sure.
Willerslev also highlights a possible link with the unusual sophistication of the ornaments and cultural objects found at Sunghir. Group-specific cultural expressions may have been used to establish distinctions between bands of early humans, providing a means of identifying who to mate with and who to avoid as partners.
• The ornamentation is incredible and there is no evidence of anything like that with Neanderthals and other archaic humans, Willerslev added.
• When you put the evidence together, it seems to be speaking to us about the really big questions; what made these people who they were as a species, and who we are as a result.