Neanderthal Project

Largest group of fossil humans are Neanderthals after all

June 13th, 2012

Largest group of fossil humans are Neanderthals after all

Fossil skull from Sima de los Huesos in Spain has many Neanderthal features. Fossil skull from Sima de los Huesos in Spain has many Neanderthal features.

The world’s largest known sample of fossil humans has been classified as the species Homo heidelbergensis but in fact are early Neanderthals, according to a study by Prof Chris Stringer of the Natural History Museum.

This puts the species Homo heidelbergensis back at the heart of human evolution as the last common ancestor that we, Homo sapiens, shared with Neanderthals, Homo neanderthalensis, says Stringer, the Museum’s Research Leader in Human Origins.

Fossil skull of Homo heidelbergensis. Fossil skull of Homo heidelbergensis.

The Status of Homo heidelbergensis study, which was published in the journal Evolutionary Anthropology this week, reviews the fossil and DNA evidence for the existence of heidelbergensis and its place in the human family tree.

Central to the discussion is the important site of La Sima de los Huesos (meaning ‘Pit of the bones’), in Atapuerca, northern Spain. It has yielded more than 6,000 fossils from about 28 individuals.

They had been identified as H. heidelbergensis by the team who originally discovered the fossils, and have been estimated to be about 600,000 years old. For some palaeontologists, such as Stringer, this has confused ideas about where heidelbergensis sits in the human family tree.

Now, however, Stringer says there is enough fossil and genetic evidence to say that the Sima material belongs to early Neanderthals, and also that it must be much younger than 600,000 years old.

‘Most of the data supporting this view actually come from studies by the Atapuerca team themselves,’ says Stringer. ‘They have shown that the skulls, jaws, teeth and skeletons of the Sima fossils show many Neanderthal features.’

The Neanderthal features include a little pit in the middle of the occipital bone at the back of the skull, the shape of the face, and the patterns of cusps on the teeth.

Ancestor of modern humans too

Because they classified the Sima material as heidelbergensis, the Atapuerca team regarded heidelbergensis, with all its Neanderthal features, as the ancestor to Neanderthals only.

However, other palaeontologists, including Stringer, consider heidelbergensis to also be the ancestor of modern humans. They believed that heidelbergensis was a widespread species, which in Africa gave rise to H. sapiens, and in Europe and Asia gave rise to the Neanderthals. But the classification and date of the Sima fossils published by the Atapuerca team contradicted this idea.

Two reconstructions of recent human evolution, one with an early date for the Sima fossils and their2 reconstructions of recent human evolution, one with an early date for the Sima fossils and their classification as Homo heidelbergensis (left), the other with them positioned as early Neanderthals and a later date (right). In this 2nd reconstruction the Denisovans are added as a possible early branch from the Neanderthal lineage.

Fossil dates

No other fossils with Neanderthal features have been dated to earlier than about 400,000 years ago. Stringer explains, ‘We would not expect clear Neanderthal traits to occur 200,000 years earlier than this.’

‘Dating these bones to such a great age greatly complicates our picture of human evolution half a million years ago.’

Both morphological and genetic studies have suggested that Neanderthals and modern humans began to branch away from each other about 400,000 years ago.

So the Sima material cannot be 600,000 years old, and must be at least 200,000 years younger, says Stringer.

Dating stalagmite

The Sima fossils are too old to be radiocarbon dated, so scientists have tried various other techniques to estimate their age. One method was to use the decay of radioactive isotopes to date the stalagmite that overlies the human fossils.

The first analysis suggested an age of around 350,000 years, but later measurements suggested an age closer to 600,000 years. ‘I think they got it right the first time,’ says Stringer.

Back as a common ancestor
Reclassifying the Sima fossils as Neanderthals rather than heidelbergensis puts heidelbergensis backReclassifying the Sima fossils as Neanderthals rather than heidelbergensis puts heidelbergensis back at the heart of human evolution as the last common ancestor.

Reclassifying the Sima fossils from heidelbergensis to early Neanderthal gives a clearer picture of the position of heidelbergensis in the human family tree, and also clarifies the pattern of human evolution in Europe.

‘Removing the Sima fossils from heidelbergensis means that the species once again makes a good common ancestor for the Neanderthals, modern humans, and probably the Denisovans (known from DNA recovered from fragmentary fossils in Siberia) too,’ says Stringer.

‘These new views on the dating and classification of the Sima material have led to a constructive scientific debate with the Atapuerca team, which will help to progress our understanding of the place of these important fossils in human evolution,’ Stringer concludes.

The Status of Homo heidelbergensis is published in the journal Evolutionary Anthropology

 

Source: http://www.nhm.ac.uk/about-us/news/2012/june/largest-group-of-fossil-humans-are-neanderthals-after-all111416.html

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Neanderthals were seafaring long before modern humans

June 7th, 2012

London, March1 (ANI): Neanderthals may have used the seas as a highway centuries before modern humans managed the same trick, researchers in Greece say.

Evidence suggests our extinct cousins criss-crossed the Mediterranean in boats from 100,000 years ago.

Neanderthals lived around the Mediterranean from 300,000 years ago. Their distinctive “Mousterian” stone tools are found on the Greek mainland and, intriguingly, have also been found on the Greek islands of Lefkada, Kefalonia and Zakynthos.

These lead to two assumptions, either the islands weren’t islands at the time, or our distant cousins crossed the water somehow.

Now, George Ferentinos of the University of Patras in Greece says we can rule out the former.

The islands, he says, have been cut off from the mainland for as long as the tools have been on them, the New Scientist reported.

Ferentinos compiled data that showed sea levels were 120 metres lower 100,000 years ago, because water was locked up in Earth’s larger ice caps.

But the seabed off Greece today drops down to around 300 metres, meaning that when Neanderthals were in the region, the sea would have been at least 180 metres deep (as reported in Journal of Archaeological Science).

Ferentinos thinks Neanderthals had a seafaring culture for tens of thousands of years. Modern humans are thought to have taken to the seas just 50,000 years ago, on crossing to Australia.

The journeys to the Greek islands from the mainland were quite short – 5 to 12 kilometres – but according to Thomas Strasser of Providence College in Rhode Island, the Neanderthals didn’t stop there.

In 2008 he found similar stone tools on Crete, which he says are at least 130,000 years old. Crete has been an island for some 5 million years and is 40 kilometres from its closest neighbour – suggesting far more ambitious journeys.

Strasser agrees Neanderthals were seafaring long before modern humans, in the Mediterranean at least. He thinks early hominins made much more use of the sea than anyone suspects, and may have used the seas as a highway, rather than seeing them as a barrier.

But the details remain lost in history. Any craft were presumably made from wood, so rotted away long ago. The oldest known Mediterranean boat, a dugout canoe from Lake Bracciano in Italy, is just 7000 years old. Ferentinos speculates that Neanderthals may have made something similar.

There is a simpler explanation for how they reached the islands, suggested Paul Pettitt of the University of Sheffield, UK: maybe they just swam there. Pettitt also points out that the tools on the islands have not been chemically dated, so estimates of their age are based entirely on their design.

 

Source: http://www.aninews.in/newsdetail9/story39484/neanderthals-were-seafaring-long-before-modern-humans.html

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Dogs ‘may have helped modern man to flourish over Neanderthals’

June 7th, 2012

London, May 16 (ANI): Our close friendship with dogs tipped the balance in favour of modern man over the Neanderthals, who had previously occupied present-day Europe for a staggering 250,000 years, an anthropologist has suggested.

For more than 32,000 years, dogs have been our faithful companions, living, eating and breathing with us as we moved from cave-dwellers to city-builders. Around this time, the planet lost our closest cousins and enemies – the Neanderthals.

Pat Shipman said that the advantages that domesticating a dog brought for us were so fundamental to our own evolution, that it made us “top dog”{ out of the competing primate species.

Shipman analysed the results of excavations of fossilised canid bones from Europe, during the time when humans and Neanderthals overlapped.

The research first of all established a framework to our early “best friend” relationships, with early humans adding dog teeth to jewellery, showing how they were worshipped, and rarely adorning cave art with images of dogs – implying dogs were treated with a reverence not shown to the animals they hunted.

The advantages dogs gave early man were huge – the animals themselves were likely to be larger than our modern day pooches, at least the size of German Shepherds.

Because of this, they could be used as “beasts of burden”, carrying animal carcasses and supplies from place to place, leaving humans to reserve their energies for the hunt.

In return, the animals gained warmth, food and companionship, or, as Shipman puts it, “a virtuous circle of cooperation”.

They may also have influenced how we communicate. Humans and dogs are the only animals which have large “whites of the eyes”, and will follow the gaze of another person.

This has not been found in other species, and it is argued that, as our man-dog relationship evolved, we learned to use these non-verbal cues more often.

As such, dogs became one of the first tools, or technologies, that humanity began to use, and as the relationship developed both ways, it became a lot deeper ingrained into our psyche.

And, in those early days where every advantage was needed to survive, Neanderthal man might simply have been unable to cope with the new species which rapidly moved across Europe.

“Animals were not incidental to our evolution into Homo sapiens – They were essential to it. They are what made us human,” the Daily Mail quoted Shipman as saying. (ANI)

 

Source: http://www.aninews.in/newsdetail9/story51468/dogs-039-may-have-helped-modern-man-to-flourish-over-neanderthals-039-.html

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Homo heidelbergensis was slightly taller than Neanderthal

June 7th, 2012

Washington, June 7 (ANI): The reconstruction of 27 complete human limb bones found in Atapuerca (Burgos, Spain) has helped scientists to determine the height of the human species Homo heidelbergensis, who inhabited Europe during the Middle Pleistocene era.

Along with its enormous quantity of fossils, one of the most important features of the Sima de los Huesos (SH) site in Atapuerca, Burgos, is the splendid state of the findings. They are so well conserved that the 27 complete bones from some 500,000 years ago have been reconstructed.

“The incredible collection allows us to estimate the height of species such as Homo heidelbergensis, who inhabited Europe during the Middle Pleistocene era and is the ancestor of the Neanderthal. Such estimations are based solely on analysis of the large complete bones, like those from the arm and the leg,” Jose Miguel Carretero Diaz, researcher at the Laboratory of Human Evolution of the University of Burgos and lead author of the study, explained to SINC.

In addition, since bones were complete, the researchers were able to determine whether they belonged to a male or female and thus calculate the height of both men and women.

“Estimations to date were based on incomplete bone samples, the length of which had to be estimated too. We also used to use formulas based on just one reference population and we were not even sure as to its appropriateness,” the researcher highlighted.

Since the most fitting race or ecology for these human beings was unknown, scientists used multiracial and multigender formulas to estimate the height for the entire population in order to reduce the error margin and get a closer insight on the reality.

As Carretero Diaz pointed out, “we calculated an overall average for the sample and one for each of the sexes. The same was done with the Neanderthal and Cro-Magnon fossils.”

The results suggest that both men and women in the Sima de los Huesos population were on average slightly higher than Neanderthal men and women.

“Neither can be described as being short and both are placed in the medium and above-medium height categories. But, both species featured tall individuals,” assured the experts.

The height of these two species is similar to that of modern day population of mid-latitudes, like in the case of Central Europe and the Mediterranean.

The humans who arrived in Europe during the Upper Palaeolithic era, Cro-Magnons or anatomically modern humans, replaced the Neanderthal populations. They were significantly taller than other human species and their average height for both sexes was higher, falling in the very tall individual category.

According to the researchers, putting aside the margin corresponding to small biotype species like Homo habilis (East Africa), Homo georgicus (Georgia) and Homo floresiensis (Flores in Indonesia), all documented humans during the Early and Middle Pleistocene Era that inhabited Africa (Homo ergaster, Homo rhodesiensis), Asia (Homo erectus) and Europe (Homo antecessor, Homo heidelbergensis and Homo neanderthalensis) seemed to have medium and above-medium heights for the most part of two millions years.

However, the researchers stated that “amongst every population we have found a tall or very tall individual.”

In their opinion, this suggests that the height of the Homo genus remained more or less stable for 2 million years until the appearance of a “ground-breaking species in this sense” in Africa just 200,000 years ago. These were the Homo sapiens, who were initially significantly taller than any other species that existed at the time.

“The explanation is found in the overall morphological change in the body biotype that prevailed in our species compared to our ancestors. The Homo sapiens had a slimmer body, lighter bones, longer legs and were taller,” the researcher added.

Scientists have documented various advantages that made the sapiens biotype more adaptable. These include their thermoregulatory, obstetric and nutritional make-up but in the eyes of the experts, the greatest advantage of this new body type was increased endurance and energy.

Carretero Diaz indicated that “larger legs, narrower hips, being taller and having lighter bones not only meant a reduction in body weight (less muscular fat) but a bigger stride, greater speed and a lower energy cost when moving the body, walking or running.”

This type of anatomy could have been highly advantageous in terms of survival in Eurasia during the Upper Pleistocene Era when two intelligent human species (the light-bodied Cro-Magnons and Neanderthals) had to face difficult climatic conditions, drastic changes in ecosystems and ecological competition.

The finding has been published in the ‘Journal of Human Evolution’ journal. (ANI)

 

Source: http://www.newstrackindia.com/newsdetails/2012/06/07/259-Homo-heidelbergensis-was-slightly-higher-than-Neanderthal-.html

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The “Red-deer Cave people” – yet another newly-discovered stone-age neighbor

June 7th, 2012

Mystery Human Fossils Put Spotlight On China

ScienceDaily (Mar. 14, 2012) — Fossils from two caves in south-west China have revealed a previously unknown Stone Age people and give a rare glimpse of a recent stage of human evolution with startling implications for the early peopling of Asia.


An artist's reconstruction of fossils from two caves in southwest China have revealed a previously unknown Stone Age people and give a rare glimpse of a recent stage of human evolution with startling implications for the early peopling of Asia. The fossils are of a people with a highly unusual mix of archaic and modern anatomical features and are the youngest of their kind ever found in mainland East Asia. Dated to just 14,500 to 11,500 years old, these people would have shared the landscape with modern-looking people at a time when China's earliest farming cultures were beginning, says an international team of scientists led by associate professor Darren Curnoe, of the University of New South Wales, and professor Ji Xueping of the Yunnan Institute of Cultural Relics and Archeology. (Credit: Art copyright by Peter Schouten)

The fossils are of a people with a highly unusual mix of archaic and modern anatomical features and are the youngest of their kind ever found in mainland East Asia.

Dated to just 14,500 to 11,500 years old, these people would have shared the landscape with modern-looking people at a time when China’s earliest farming cultures were beginning, says an international team of scientists led by Associate Professor Darren Curnoe, of the University of New South Wales, and Professor Ji Xueping of the Yunnan Institute of Cultural Relics and Archeology.

Details of the discovery are published in the journal PLoS ONE. The team has been cautious about classifying the fossils because of their unusual mosaic of features.

“These new fossils might be of a previously unknown species, one that survived until the very end of the Ice Age around 11,000 years ago,” says Professor Curnoe.

“Alternatively, they might represent a very early and previously unknown migration of modern humans out of Africa, a population who may not have contributed genetically to living people.”

The remains of at least three individuals were found by Chinese archaeologists at Maludong (or Red Deer Cave), near the city of Mengzi in Yunnan Province during 1989. They remained unstudied until research began in 2008, involving scientists from six Chinese and five Australian institutions.

A Chinese geologist found a fourth partial skeleton in 1979 in a cave near the village of Longlin, in neighbouring Guangxi Zhuang Autonomous Region. It stayed encased in a block of rock until 2009 when the international team removed and reconstructed the fossils.

The skulls and teeth from Maludong and Longlin are very similar to each other and show an unusual mixture of archaic and modern anatomical features, as well as some previously unseen characters.

While Asia today contains more than half of the world’s population, scientists still know little about how modern humans evolved there after our ancestors settled Eurasia some 70,000 years ago, notes Professor Curnoe.

The scientists are calling them the “Red-deer Cave people” because they hunted extinct red deer and cooked them in the cave at Maludong.

The Asian landmass is vast and scientific attention on human origins has focussed largely on Europe and Africa: research efforts have been hampered by a lack of fossils in Asia and a poor understanding of the age of those already found.

Until now, no fossils younger than 100,000 years old have been found in mainland East Asia resembling any species other than our own (Homo sapiens). This indicated the region had been empty of our evolutionary cousins when the first modern humans appeared. The new discovery suggests this might not have been the case after all and throws the spotlight once more on Asia.

“Because of the geographical diversity caused by the Qinghai-Tibet plateau, south-west China is well known as a biodiversity hotspot and for its great cultural diversity. That diversity extends well back in time” says Professor Ji.

In the last decade, Asia has produced the 17,000-year-old and highly enigmatic Indonesian Homo floresiensis (“The Hobbit”) and evidence for modern human interbreeding with the ancient Denisovans from Siberia.

“The discovery of the red-deer people opens the next chapter in the human evolutionary story — the Asian chapter — and it’s a story that’s just beginning to be told,” says Professor Curnoe.

Source: http://www.sciencedaily.com/releases/2012/03/120314124007.htm

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