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Friday, August 16, 2013

Our Neanderthal Teachers

McPherron and his colleagues have
: discovered that Neanderthals
: created a specialized kind of
: bone tool previously only seen
: in modern humans. These tools
: are about 51,000 years old,
: making them the oldest known
: examples of such tools in Europe
: and predating the known arrival
: of modern humans.

Earliest Hominin Carnivory


The emergence of lithic technology by ~2.6 million years ago (Ma) is
often interpreted as a correlate of increasingly recurrent hominin
acquisition and consumption of animal remains. Associated faunal
evidence, however, is poorly preserved prior to ~1.8 Ma, limiting our
understanding of early archaeological (Oldowan) hominin carnivory.
Here, we detail three large well-preserved zooarchaeological
assemblages from Kanjera South, Kenya. The assemblages date to ~2.0
Ma, pre-dating all previously published archaeofaunas of appreciable
size. At Kanjera, there is clear evidence that Oldowan hominins
acquired and processed numerous, relatively complete, small ungulate
carcasses. Moreover, they had at least occasional access to the
fleshed remains of larger, wildebeest-sized animals. The overall
record of hominin activities is consistent through the stratified
sequence � spanning hundreds to thousands of years � and provides the
earliest archaeological evidence of sustained hominin involvement with
fleshed animal remains (i.e., persistent carnivory), a foraging
adaptation central to many models of hominin evolution.

"Paleoenvironmental analyses indicate that the assemblages
formed on a grassy plain set between a freshwater lake and the
wooded slopes of nearby hills and mountains. The recovered
faunas consist primarily of grassland-adapted bovids (Parmularius,
Antidorcas), equids (Equus), and suids (Metridiochoerus), with
waterdependent taxa (e.g., Hippopotamus, Crocodylus, and reduncine
bovids) also present in limited numbers. Isotopic analyses of
dental enamel and pedogenic carbonates concordantly indicate a
grassland setting at KJS."

Y Adam as old as M Eve?
Almost every man alive can trace his origins to one man who lived about 135,000 years ago, new research suggests. And that ancient man likely shared the planet with the mother of all women.
The findings, detailed Thursday, Aug. 1, in the journal Science, come from the most complete analysis of the male sex chromosome, or the Y chromosome, to date. The results overturn earlier research, which suggested that men's most recent common ancestor lived just 50,000 to 60,000 years ago.
Despite their overlap in time, ancient "Adam" and ancient "Eve" probably didn't even live near each other, let alone mate. [The 10 Biggest Mysteries of the First Humans]
"Those two people didn't know each other," said Melissa Wilson Sayres, a geneticist at the University of California, Berkeley, who was not involved in the study.
Tracing historyResearchers believe that modern humans left Africa between 60,000 and 200,000 years ago, and that the mother of all women likely emerged from East Africa. But beyond that, the details get fuzzy.
The Y chromosome is passed down identically from father to son, so mutations, or point changes, in the male sex chromosome can trace the male line back to the father of all humans. By contrast, DNA from the mitochondria, the energy powerhouse of the cell, is carried inside the egg, so only women pass it on to their children. The DNA hidden inside mitochondria, therefore, can reveal the maternal lineage to an ancient Eve.
But over time, the male chromosome gets bloated with duplicated, jumbled-up stretches of DNA, said study co-author Carlos Bustamante, a geneticist at Stanford University in California. As a result, piecing together fragments of DNA from gene sequencing was like trying to assemble a puzzle without the image on the box top, making thorough analysis difficult.
Y chromosomeBustamante and his colleagues assembled a much bigger piece of the puzzle by sequencing the entire genome of the Y chromosome for 69 men from seven global populations, from African San Bushmen to the Yakut of Siberia.
By assuming a mutation rate anchored to archaeological events (such as the migration of people across the Bering Strait), the team concluded that all males in their global sample shared a single male ancestor in Africa roughly 125,000 to 156,000 years ago.
In addition, mitochondrial DNA from the men, as well as similar samples from 24 women, revealed that all women on the planet trace back to a mitochondrial Eve, who lived in Africa between 99,000 and 148,000 years ago almost the same time period during which the Y-chromosome Adam lived.
More ancient AdamBut the results, though fascinating, are just part of the story, said Michael Hammer, an evolutionary geneticist at the University of Arizona who was not involved in the study.
A separate study in the same issue of the journal Science found that men shared a common ancestor between 180,000 and 200,000 years ago.
And in a study detailed in March in the American Journal of Human Genetics, Hammer's group showed that several men in Africa have unique, divergent Y chromosomes that trace back to an even more ancient man who lived between 237,000 and 581,000 years ago. [Unraveling the Human Genome: 6 Molecular Milestones]
"It doesn't even fit on the family tree that the Bustamante lab has constructed. It's older," Hammer told LiveScience.
Gene studies always rely on a sample of DNA and, therefore, provide an incomplete picture of human history. For instance, Hammer's group sampled a different group of men than Bustamante's lab did, leading to different estimates of how old common ancestors really are.
Adam and Eve?These primeval people aren't parallel to the biblical Adam and Eve. They weren't the first modern humans on the planet, but instead just the two out of thousands of people alive at the time with unbroken male or female lineages that continue on today.
The rest of the human genome contains tiny snippets of DNA from many other ancestors they just don't show up in mitochondrial or Y-chromosome DNA, Hammer said. (For instance, if an ancient woman had only sons, then her mitochondrial DNA would disappear, even though the son would pass on a quarter of her DNA via the rest of his genome.)
As a follow-up, Bustamante's lab is sequencing Y chromosomes from nearly 2,000 other men. Those data could help pinpoint precisely where in Africa these ancient humans lived.
"It's very exciting," Wilson Sayres told LiveScience. "As we get more populations across the world, we can start to understand exactly where we came from physically."
Copyright 2013 LiveScience, a TechMediaNetwork company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

Read more:

10,000 BC Lunar Calendar

NE Scotland, Orkney & Shetland
In association with


'World's oldest calendar' discovered in Scottish field

Professor Vince Gaffney, an expert in landscape archaeology, explains what the pits appear to show
Archaeologists believe they have discovered the world's oldest lunar "calendar" in an Aberdeenshire field.
Excavations of a field at Crathes Castle found a series of 12 pits which appear to mimic the phases of the moon and track lunar months.
A team led by the University of Birmingham suggests the ancient monument was created by hunter-gatherers about 10,000 years ago.
The pit alignment, at Warren Field, was first excavated in 2004.
The experts who analysed the pits said they may have contained a wooden post.
The Mesolithic "calendar" is thousands of years older than previous known formal time-measuring monuments created in Mesopotamia.

Start Quote

It is remarkable to think that our aerial survey may have helped to find the place where time itself was invented”
End Quote Dave Cowley RCAHMS
The analysis has been published in the journal, Internet Archaeology.
The pit alignment also aligns on the Midwinter sunrise to provided the hunter-gatherers with an annual "astronomic correction" in order to better follow the passage of time and changing seasons.
Vince Gaffney, Professor of Landscape Archaeology at Birmingham, led the analysis project.
He said: "The evidence suggests that hunter-gatherer societies in Scotland had both the need and sophistication to track time across the years, to correct for seasonal drift of the lunar year and that this occurred nearly 5,000 years before the first formal calendars known in the Near East.
"In doing so, this illustrates one important step towards the formal construction of time and therefore history itself."
An illustration of how the pits would have worked An illustration of how the pits would have worked
The universities of St Andrews, Leicester and Bradford were also involved.
Dr Richard Bates, of the University of St Andrews, said the discovery provided "exciting new evidence" of the early Mesolithic Scotland.
He added: "This is the earliest example of such a structure and there is no known comparable site in Britain or Europe for several thousands of years after the monument at Warren Field was constructed."
The Warren Field site was first discovered as unusual crop marks spotted from the air by the Royal Commission on the Ancient and Historical Monuments of Scotland (RCAHMS).
Dave Cowley, aerial survey projects manager at RCAHMS, said: "We have been taking photographs of the Scottish landscape for nearly 40 years, recording thousands of archaeological sites that would never have been detected from the ground.
"Warren Field stands out as something special, however. It is remarkable to think that our aerial survey may have helped to find the place where time itself was invented."
Prof Vince Gaffney Prof Vince Gaffney led the project to analyse the pits at Warren Field
Crathes Castle and its estate is in the care of the National Trust for Scotland (NTS).
From 2004 to 2006, trust staff and Murray Archaeological Services excavated the site.
NTS archaeologist Dr Shannon Fraser said: "This is a remarkable monument, which is so far unique in Britain.
"Our excavations revealed a fascinating glimpse into the cultural lives of people some 10,000 years ago - and now this latest discovery further enriches our understanding of their relationship with time and the heavens."


High speed accurate throwing developed ~2 mya
Elastic energy storage in the shoulder and the evolution of high-speed
throwing in Homo

Nature 498, 483–486 (27 June 2013)


Some primates, including chimpanzees, throw objects occasionally, but
only humans regularly throw projectiles with high speed and accuracy.
Darwin noted that the unique throwing abilities of humans, which were
made possible when bipedalism emancipated the arms, enabled foragers
to hunt effectively using projectiles. However, there has been little
consideration of the evolution of throwing in the years since Darwin
made his observations, in part because of a lack of evidence of when,
how and why hominins evolved the ability to generate high-speed throws.
Here we use experimental studies of humans throwing projectiles to show
that our throwing capabilities largely result from several derived
anatomical features that enable elastic energy storage and release at
the shoulder. These features first appear together approximately 2
million years ago in the species Homo erectus. Taking into
consideration archaeological evidence suggesting that hunting activity
intensified around this time, we conclude that selection for throwing as
a means to hunt probably had an important role in the evolution of the
genus Homo.