Saturday, March 24, 2012
New Human Species Identified?
Before modern humanity overran the world, every niche was filled by adapted primates over a million years at the least. The arrival of modern humanity brought numbers and the inevitable extinction of related small populations. This may have meant no more that a dawn raid on a small hunting camp, the killing of the males and the forced submission of the women.
The problem was that the human population numbered in the hundreds while competitors numbered in the tens. Two cycles of dawn raids and the offspring will have at best twenty five percent of the original gene stock.
So while unique archaic hunting bands operated world wide in a wide variety of related breeds and species even, the weight of numbers quickly overwhelmed the genetic contribution unique to them.
The report here already demonstrates that modern humanity was setting up farming and the large populations needed to absorb these peoples. Surely the same happened to the remnant Neanderthal populations. The moment a family is able to gather and store food in one locale it is able to produce a larger village and ample manpower to throw off any other threats.
Human fossils hint at new species
By Jonathan AmosScience correspondent, BBC News
14 March 2012 Last updated at 11:19 ET
Scientists say the specimens display features that are quite distinct from fully modern humans
The remains of what may be a previously unknown human species have been identified in southern
The bones, which represent at least five individuals, have been dated to between 11,500 and 14,500 years ago.
But scientists are calling them simply the
people, after one of the sites where they were unearthed. Red Deer Cave
The team has told the PLoS One journal that far more detailed analysis of the fossils is required before they can be ascribed to a new human lineage.
"We're trying to be very careful at this stage about definitely classifying them," said study co-leader Darren Curnoe from the
University of New South
Wales, . Australia
"One of the reasons for that is that in the science of human evolution or palaeoanthropology, we presently don't have a generally agreed, biological definition for our own species (Homo sapiens), believe it or not. And so this is a highly contentious area," he told BBC News.
Much of the material has been in Chinese collections for some time but has only recently been subjected to intense investigation.
The remains of some of the individuals come from Maludong (or
Red Deer Cave),
near the city of Mengzi in .
A further skeleton was discovered at Longlin, in neighbouring Yunnan Province . Guangxi Province
The skulls and teeth from the two locations are very similar to each other, suggesting they are from the same population.
Scientists continue to excavate at Maludong
But their features are quite distinct from what you might call a fully modern human, says the team. Instead, the
people have a mix of archaic and modern characteristics. Red Deer Cave
In general, the individuals had rounded brain cases with prominent brow ridges. Their skull bones were quite thick. Their faces were quite short and flat and tucked under the brain, and they had broad noses.
Their jaws jutted forward but they lacked a modern-human-like chin. Computed Tomography (X-ray) scans of their brain cavities indicate they had modern-looking frontal lobes but quite archaic-looking anterior, or parietal, lobes. They also had large molar teeth.
Dr Curnoe and colleagues put forward two possible scenarios in their PLoS One paper for the origin of the
One posits that they represent a very early migration of a primitive-looking Homo sapiens that lived separately from other forms in
before dying out.
people might have
looked 11,500 years ago Red Deer
Another possibility contends that they were indeed a distinct Homo species that evolved in
and lived alongside our own kind until remarkably recently.
A third scenario being suggested by scientists not connected with the research is that the
people could be
hybrids. Red Deer
"It's possible these were modern humans who inter-mixed or bred with archaic humans that were around at the time," explained Dr Isabelle De Groote, a palaeoanthropologist from
London's . Natural History Museum
"The other option is that they evolved these more primitive features independently because of genetic drift or isolation, or in a response to an environmental pressure such as climate."
Dr Curnoe agreed all this was "certainly possible".
Attempts are being made to extract DNA from the remains. This could yield information about interbreeding, just as genetic studies have on the closely related human species - the Neanderthals and an enigmatic group of people from
Siberia known as the Denisovans.
Whatever their true place in the Homo family tree, the
People are an
important find simply because of the dearth of well dated, well described
specimens from this part of the world. Red Deer
And their unearthing all adds to the fascinating and increasingly complex story of human migration and development.
Red Deer People were living at
what was a really interesting time in , during what we call the
epipalaeolithic or the end of the Stone Age," says Dr Curnoe. China
"Not far from Longlin, there are quite well known archaeological sites where some of the very earliest evidence for the epipalaeolithic in
East Asia has been found.
"These were occupied by very modern looking people who are already starting to make ceramics - pottery - to store food. And they're already harvesting from the landscape wild rice. There was an economic transition going on from full-blown foraging and gathering towards agriculture."
Quite how the
People fit into this picture is unclear. The research team is promising to
report further investigations into some of the stone tools and cultural
artefacts discovered at the dig sites. Red Deer
The co-leader on the project is Professor Ji Xueping of the Yunnan Institute of Cultural Relics and Archaeology.