Oldest Human DNA Reveals Mysterious Branch of Humanity

Charles Q. Choi, LiveScience Contributor, 12/04/13

The oldest known human DNA found yet reveals human evolution was even more confusing than thought, researchers say.

The DNA, which dates back some 400,000 years, may belong to an unknown human ancestor, say scientists. These new findings could shed light on a mysterious extinct branch of humanity known as Denisovans, who were close relatives of Neanderthals, scientists added.

Although modern humans are the only surviving human lineage, others once strode the Earth. These included Neanderthals, the closest extinct relatives of modern humans, and the relatively newfound Denisovans, who are thought to have lived in a vast expanse from Siberia to Southeast Asia. Research shows that the Denisovans shared a common origin with Neanderthals but were genetically distinct, with both apparently descending from a common ancestral group that had diverged earlier from the forerunners of modern humans.

[See Images of Excavation & Mysterious 'New Hominid']

Genetic analysis suggests the ancestors of modern humans interbred with both these extinct lineages. Neanderthal DNA makes up 1 to 4 percent of modern Eurasian genomes, and Denisovan DNA makes up 4 to 6 percent of modern New Guinean and Bougainville Islander genomes in the Melanesian islands.

Pit of Bones

To discover more about human origins, researchers investigated a human thighbone unearthed in the Sima de los Huesos, or "Pit of Bones," an underground cave in the Atapuerca Mountains in northern Spain. The bone is apparently 400,000 years old.

"This is the oldest human genetic material that has been sequenced so far," said study lead author Matthias Meyer, a molecular biologist at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany. "This is really a breakthrough — we'd never have thought it possible two years ago that we could study the genetics of human fossils of this age." Until now, the previous oldest human DNA known came from a 100,000-year-old Neanderthal from a cave in Belgium.

The Sima de los Huesos is about 100 feet (30 meters) below the surface at the bottom of a 42-foot (13-meter) vertical shaft. Archaeologists suggest the bones may have been washed down it by rain or floods, or that the bones were even intentionally buried there.

This Pit of Bones has yielded fossils of at least 28 individuals, the world's largest collection of human fossils dating from the Middle Pleistocene, about 125,000 to 780,000 years ago.

"This is a very interesting time range," Meyer told LiveScience. "We think the ancestors of modern humans and Neanderthals diverged maybe some 500,000 years ago." The oldest fossils of modern humans found yet date back to about 200,000 years ago.

Denisovan relative?

The researchers reconstructed a nearly complete genome of this fossil's mitochondria — the powerhouses of the cell, which possess their own DNA and get passed down from the mother. The fossils unearthed at the site resembled Neanderthals, so researchers expected this mitochondrial DNA to be Neanderthal.

Surprisingly, the mitochondrial DNA reveals this fossil shared a common ancestor not with Neanderthals, but with Denisovans, splitting from them about 700,000 years ago. This is odd, since research currently suggests the Denisovans lived in eastern Asia, not in western Europe, where this fossil was uncovered. The only known Denisovan fossils so far are a finger bone and a molar found in Siberia.

[Denisovan Gallery: Tracing the Genetics of Human Ancestors]

"This opens up completely new possibilities in our understanding of the evolution of modern humans, Neanderthals and Denisovans," Meyer said.

The researchers suggest a number of possible explanations for these findings. First, this specimen may have been closely related to the ancestors of Denisovans. However, this seems unlikely, since the presence of Denisovans in western Europe would suggest an extensive overlap of territory with Neanderthal ancestors, raising the question of how both groups could diverge genetically while overlapping in range. Moreover, the one known Denisovan tooth is significantly different from teeth seen at the Pit of Bones.

Second, the Sima de los Huesos humans may be related to the ancestors of both Neanderthals and Denisovans. The researchers consider this plausible given the fossil's age, but they would then have to explain how two very different mitochondrial DNA lineages stemmed from one group, one leading to Denisovans, the other to Neanderthals.

Third, the humans found at the Sima de los Huesos may be a lineage distinct from both Neanderthals and Denisovans that later perhaps contributed mitochondrial DNA to Denisovans. However, this suggests this group was somehow both distinct from Neanderthals but also independently evolved several Neanderthal-like skeletal features.

Fourth, the investigators suggest a currently unknown human lineage brought Denisovan-like mitochondrial DNA into the Pit of Bones region, and possibly also to the Denisovans in Asia.

"The story of human evolution is not as simple as we would have liked to think," Meyer said. "This result is a big question mark. In some sense, we know less about the origins of Neanderthals and Denisovans than we knew before."

The scientists now hope to learn more about these fossils by retrieving DNA from their cell nuclei, not their mitochondria. However, this will be a huge challenge — the researchers needed almost 2 grams of bone to analyze mitochondrial DNA, which outnumbers nuclear DNA by several hundred times within the cell.

The scientists detailed their findings in the Dec. 5 issue of the journal Nature.

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http://news.yahoo.com/oldest-human-dna-reveals-mysterious-branch-humanity-181139436.html

Skull suggests three early human species were one                

Controversial analysis of long-faced fossil proposes that Homo erectus should subsume two other hominin species.

Sid Perkins, 10/17/13

One of the most complete early human skulls yet found suggests that what scientists thought were three hominin species may in fact be one.

This controversial claim comes from a comparison between the anatomical features of a 1.8-million-year-old fossil skull with those of four other skulls from the same excavation site at Dmanisi, Georgia. The wide variability in their features suggests that Homo habilis, Homo rudolfensis and Homo erectus, the species so far identified as existing worldwide in that era, might represent a single species. The research is published in Science today¹.

The newly described skull -- informally known as 'skull 5' -- was unearthed in 2005. When combined with a jawbone found five years before and less than 2 metres away, it “is the most complete skull of an adult from this date”, says Marcia Ponce de León, a palaeoanthropologist at the Anthropological Institute and Museum in Zurich, Switzerland, and one of the authors of the study.

The volume of skull 5’s braincase is only 546 cubic centimetres, about one-third that of modern humans, she notes. Despite that low volume, the hominin’s face was relatively large and protruded more than the faces of the other four skulls found at the site, which have been attributed to H. erectus.

Having five skulls from one site provides an unprecedented opportunity to study variation in what presumably was a single population, says co-author Christoph Zollikofer, a neurobiologist at the same institute as Ponce de León. All of the skulls excavated so far were probably deposited within a 20,000-year time period, he notes.

The Dmanisi skulls look quite different from one another, Zollikofer says, “so it’s tempting to publish them as different species. Yet we know that these individuals came from the same location and the same geological time, so they could, in principle, represent a single population of a single species.”

Humans and chimps

The researchers' statistical data seem to back that notion. For example, the volume of skull 5 is only about 75% that of the largest skull unearthed at the Dmanisi site -- a disparity that may seem large but that falls within the variation seen among modern humans and within chimpanzees. The variation also falls within the range seen in all hominins worldwide from the era, says Zollikofer.

“Like so many finds, [the skull] adds to what we know, but does not necessarily clarify or simplify things,” says Robert Foley, a paleoanthropologist at the University of Cambridge, UK. Nevertheless, he notes, the results of the new analysis must change the way scientists think about the nature and magnitude of anatomical variation in early Homo.

If the three hominin species inhabiting Earth about 1.8 million years ago were collapsed into one, H. habilis and H. ruldofensis would be subsumed into H. erectus -- largely owing to the similarities of the Dmanisi skulls to those known for the latter species, says Zollikofer.

Anatomical traits

But cramming the three species, which overall inhabited areas from Africa to Indonesia, under theH. erectus umbrella might not be scientifically justified, says Fred Spoor, a palaeontologist at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany.

The new study, he says, used statistical analyses of general cranial shape that are not necessarily good at discriminating between species. Rather than those general assessments, he explains, the researchers should have analysed specific anatomical traits, such as the height of the braincase or the diameter of the eye socket. Such easily quantifiable characteristics are typically used to identify species and construct evolutionary family trees.

Nature

doi:10.1038/nature.2013.13972

References

1.     Lordkipanidze, D. et al. Science 342, 326–331 (2013). Show context

Early Humans Lived in China 1.7 Million Years Ago

Charles Choi, LiveScience Contributor, 08/15/13

An extinct species of tool-making humans apparently occupied a vast area in China as early as 1.7 million years ago, researchers say.

The human lineage evolved in Africa, with now-extinct species of humans dispersing away from their origin continent more than a million years before modern humans did. Scientists would like to learn more about when and where humans went to better understand what drove human evolution.

Researchers investigated the Nihewan Basin, which lies in a mountainous region about 90 miles (150 kilometers) west of Beijing. It holds more than 60 sites from the Stone Age, with thousands of stone tools found there since 1972 — relatively simple types, such as stone flakes altogether known as the Oldowan. Researchers suspect these artifacts belonged to Homo erectus, "thought to be ancestral to Homo sapiens," Hong Ao, a paleomagnetist at the Chinese Academy of Sciences in Xi'an, told LiveScience. [Photos: New Human Ancestors from Kenya]

The exact age of these sites was long uncertain. To find out, Ao and his colleagues analyzed the earth above, below and in which stone tools at the Shangshazui site in the Nihewan Basin were found. The tools in question were stone blades potentially used for cutting or scraping.

The scientists analyzed the way in which the samples of earth were magnetized — since the Earth's magnetic field has regularly flipped numerous times over millions of years, looking at the manner in which the magnetic fields of minerals are oriented can shed light on how old they are. The researchers discovered this site in northern China might be about 1.6 million to 1.7 million years old, making it 600,000 or 700,000 years older than previously thought.

Horse, elephant and other fossils suggest the area back when the stone tools were made was mainly grassland interspersed with patches of woodland. A lake between the mountains there was probably a major attraction for hominid explorers, providing water and a range of other food sources, while the mountains could have represented an important material source for making stone tools. The researchers suggest hominid migrations to East Asia during the early Stone Age were a consequence of increasing cooling and aridity in Africa and Eurasia.

Given that slightly older artifacts and bones belonging to Homo erectus were previously discovered in southern China more than 1,500 miles (2,500 km) away, these new findings suggest early and now-extinct human species may potentially have occupied a huge territory in China.

"Homo erectus occupied a vast area in China by 1.7 million to 1.6 million years ago," Ao said.

The scientists detailed their findings online Aug. 15 in the journal Scientific Reports.

Follow LiveScience @livescience, Facebook & Google+. Original article on LiveScience.

New Primate Fossil Points to 'Out of Asia' Theory

Charles Choi, LiveScience.com, 06/04/12

The ancestors of monkeys, apes and humans may have originated in Asia and not Africa as often thought, new fossils suggest.

The origin of anthropoids -- the simians, or "higher primates," which include monkeys, apes and humans -- has been debated for decades among scientists. Although fossils unearthed in Egypt have long suggested that Africa was the cradle for anthropoids, other bones revealed in the last 15 years or so raised the possibility that Asia may be their birthplace.

Now, an international team of scientists has unearthed a new fossil in Southeast Asia that may prove that anthropoids originated in what is now the East, shedding light on a pivotal step in primate and human evolution.

The fossil is named Afrasia djijidae -- Afrasia from how early anthropoids are now found intercontinentally in both Africa and Asia, djijidae in memory of a young girl from village of Mogaung in central Myanmar, the nation where the remains were found. The four known teeth of Afrasia were recovered after six years of sifting through tons of sediment, often working with oxcarts, since even cars with four-wheel drive cannot penetrate the area. [See Photos of the Myanmar Primate]

The teeth of 37-million-year-old Afrasia closely resemble those of another early anthropoid, the 38-million-year-old Afrotarsius libycus, recently discovered in the Sahara Desert of Libya. The anthropoids in Libya were far more diverse at that early time in Africa than scientists had thought, which suggested they actually originated elsewhere. The close similarity between Afrasia and Afrotarsius now suggests that early anthropoids colonized Africa from Asia.

This migration from Asia ultimately helps set the stage for the later evolution of apes and humans in Africa. "Africa is the place of origin of man, and Asia is the place of origins of our far ancestors," researcher Jean-Jacques Jaeger, a paleontologist at the University of Poitiers in France, told LiveScience.

The shape of the Asian Afrasia and the North African Afrotarsius fossils suggest these animals probably ate insects. The size of their teeth hints that in life these animals weighed around 3.5 ounces (100 grams), roughly the size of a modern tarsier.

It remains an open question how early anthropoids actually migrated from Asia to Africa. Back then, the two continents were separated by a more extensive version of the modern Mediterranean Sea, called the Tethys Sea. Early anthropoids may have either swum from island to island from Asia to Africa, or possibly have been carried on naturally occurring rafts of logs and other material washed out to sea by floods and storms. Other animal groups apparently migrated from Asia to Africa at this time as well, such as rodents and extinct pig-like animals known as anthracotheres, Jaeger said.

After early anthropoids made their way to Africa, those left behind apparently died out in Asia. "Around 34 million years ago, there was a dramatic glacial event that cooled the world climate and affected Asia more than Africa. During that crisis, we suppose that all primitive Asian anthropoids disappeared," Jaeger said.

The anthropoids we see in Asia now, such as gibbons and orangutans, "immigrated from Africa some 20 million years ago," Jaeger said.

The researchers suggest early anthropoids were once present in areas between Myanmar and Libya. However, such fossils have yet to be unearthed, in part due to safety concerns in some of those regions -- for instance, Afghanistan.

The scientists detailed their findings online today (June 4) in the journal Proceedings of the National Academy of Sciences.

• Image Gallery: Our Closest Human Ancestor
• Image Gallery: Cute Gelada Monkeys
• Top 10 Mysteries of the First Humans

Copyright 2012 LiveScience, a TechMediaNetwork company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

http://news.yahoo.com/primate-fossil-points-asia-theory-191422436.html

Trail of 'Stone Breadcrumbs' Reveals the Identity of One of the First Human Groups to Leave Africa

ScienceDaily (Nov. 30, 2011) — A series of new archaeological discoveries in the Sultanate of Oman, nestled in the southeastern corner of the Arabian Peninsula, reveals the timing and identity of one of the first modern human groups to migrate out of Africa, according to a research article published in the open-access journal PLoS ONE.

An international team of archaeologists and geologists working in the Dhofar Mountains of southern Oman, led by Dr. Jeffrey Rose of the University of Birmingham, report finding over 100 new sites classified as "Nubian Middle Stone Age (MSA)." Distinctive Nubian MSA stone tools are well known throughout the Nile Valley; however, this is the first time such sites have ever been found outside of Africa. According to the authors, the evidence from Oman provides a "trail of stone breadcrumbs" left by early humans migrating across the Red Sea on their journey out of Africa. "After a decade of searching in southern Arabia for some clue that might help us understand early human expansion, at long last we've found the smoking gun of their exit from Africa," says Rose. "What makes this so exciting," he adds, "is that the answer is a scenario almost never considered." These new findings challenge long-held assumptions about the timing and route of early human expansion out of Africa.

Using a technique called Optically Stimulated Luminescence (OSL) to date one of the sites in Oman, researchers have determined that Nubian MSA toolmakers had entered Arabia by 106,000 years ago, if not earlier. This date is considerably older than geneticists have put forth for the modern human exodus from Africa, who estimate the dispersal of our species occurred between 70,000 and 40,000 years ago. Even more surprising, all of the Nubian MSA sites were found far inland, contrary to the currently accepted theory that envisions early human groups moving along the coast of southern Arabia. "Here we have an example of the disconnect between theoretical models versus real evidence on the ground," says co-author Professor Emeritus Anthony Marks of Southern Methodist University. "The coastal expansion hypothesis looks reasonable on paper, but there is simply no archaeological evidence to back it up.

Genetics predict an expansion out of Africa after 70,000 thousand years ago, yet we've seen three separate discoveries published this year with evidence for humans in Arabia thousands, if not tens of thousands of years prior to this date." The presence of Nubian MSA sites in Oman corresponds to a wet period in Arabia's climatic history, when copious rains fell across the peninsula and transformed its barren deserts to sprawling grasslands. "For a while," remarks Rose, "South Arabia became a verdant paradise rich in resources -- large game, plentiful freshwater, and high-quality flint with which to make stone tools." Far from innovative fishermen, it seems that early humans spreading from Africa into Arabia were opportunistic hunters traveling along river networks like highways. Whether or not these pioneers were able to survive in Arabia during the hyperarid conditions of the Last Ice Age is another matter -- a mystery that will require archaeologists to continue combing the deserts of southern Arabia, hot on the trail of stone breadcrumbs.

The Dhofar Archaeological Project is conducted under the auspices of the Ministry of Heritage and Culture in Oman. The team is composed of an interdisciplinary group of researchers from the University of Birmingham and Oxford Brookes University, UK; Arizona State University and Southern Methodist University, USA; Institute of Archaeology, National Academy of Sciences, Ukraine; Institute of Archaeology of the Academy of Science, Czech Republic; University of Tübingen, Germany, and the University of Wollongong, Australia. The project is funded by research grants from the UK Arts and Humanities Research Council and the Australian Research Council.

http://www.sciencedaily.com/releases/2011/11/111130171049.htm

Brazil government identifies uncontacted tribe

Juliana Barbassa, Associated Press

RIO DE JANEIRO – The Brazilian government confirmed this week the existence of an uncontacted tribe in a southwestern area of the Amazon rain forest.

Three large clearings in the area had been identified by satellite, but the population's existence was only verified after airplane expeditions in April gathered more data, the National Indian Foundation said in a news release Monday.

The government agency, known by its Portuguese acronym Funai, uses airplanes to avoid disrupting isolated groups. Brazil has a policy of not contacting such tribes but working to prevent the invasion of their land to preserve their autonomy. Funai estimates 68 isolated populations live in the Amazon.

The most recently identified tribe, estimated at around 200 individuals, live in four large, straw-roofed buildings and grow corn, bananas, peanuts and other crops. According to Funai, preliminary observation indicates the population likely belongs to the pano language group, which extends from the Brazilian Amazon into the Peruvian and Bolivian jungle.

The community is near the border with Peru in the massive Vale do Javari reservation, which is nearly the size of Portugal and is home to at least 14 uncontacted tribes.

"The work of identifying and protecting isolated groups is part of Brazilian public policy," said the Funai coordinator for Vale do Javari, Fabricio Amorim, in a statement. "To confirm something like this takes years of methodical work."

The region has a constellation of uncontacted peoples considered the largest in the world, said Amorim. In addition to the 14 known groups, Funai has identified through satellite images or land excursions up to eight more tribes.

That adds up to a population of about 2,000 individuals in the reservation, Amorim said.

Their culture, and even their survival, is threatened by illegal fishing, hunting, logging and mining in the area, along with deforestation by farmers, missionary activity and drug trafficking along Brazil's borders, Amorim said.

Oil exploration in the Peruvian Amazon could also destabilize the region, he said.

In spite of the threats, most of Brazil's indigenous groups maintain their languages and traditions.

Many have long fought for control of land in which they've traditionally lived on. They won legal rights to reclaim that territory in Brazil's 1988 constitution, which declared that all indigenous ancestral lands be demarcated and turned over to tribes within five years.

So far, 11 percent of Brazilian territory and nearly 22 percent of the Amazon has been turned over to such groups.

http://news.yahoo.com/s/ap/20110621/ap_on_sc/lt_brazil_uncontacted_tribe

Were ancient human migrations two-way streets?

Randolph E. Schmid, Ap Science Writer, 06/06/11

WASHINGTON – The worldwide spread of ancient humans has long been depicted as flowing out of Africa, but tantalizing new evidence suggests it may have been a two-way street.

A long-studied archaeological site in a mountainous region between Europe and Asia was occupied by early humans as long as 1.85 million years ago, much earlier than the previous estimate of 1.7 million years ago, researchers report in Tuesday's edition of Proceedings of the National Academy of Sciences.

Early human Homo erectus is known to have occupied the site at Dmanisi later. Discovering stone tools and materials from a much earlier date raises the possibility that Homo erectus evolved in Eurasia and might have migrated back to Africa, the researchers said — though much study is needed to confirm that idea.

"The accumulating evidence from Eurasia is demonstrating increasingly old and primitive populations," said Reid Ferring of the University of North Texas. Dmanisi is located in the Republic of Georgia.

"The recently discovered data show that Dmanisi was occupied at the same time as, if not before, the first appearance of Homo erectus in east Africa," the team led by Ferring and David Lordkipanidze of the Georgia National Museum reported. They uncovered more than 100 stone artifacts in deep layers at the site. Previously, fossil bones from a later period had been found at the site.

The new discovery shows that the Caucasus region was inhabited by a sustained population, not just transitory colonists. "We do not know as yet what the first occupants looked like, but the implication is that they were similar to, or possibly even more primitive than those represented by Dmanisi's fossils," Ferring explained.

The occupants of Dmanisi "are the first representatives of our own genus outside Africa, and they represent the most primitive population of the species Homo erectus known to date," added Lordkipanidze. The geographic origins of H. erectus are still unknown.

The early humans at Dmanisi "might be ancestral to all later H. erectus populations, which would suggest a Eurasian origin of H. erectus," said Lordkipanidze. However, there's another theory as well: H. erectus originated in Africa, and the Dmanisi group might represent its first migration out of Africa.

Wil Roebroeks, a professor of archaeology at Leiden University in the Netherlands, said the new findings suggest a sustained regional population which had successfully adapted to the temperate environment of the southern Caucasus at about 1.8 million years ago.

He called it "an important observation for our views on the earliest colonization of Eurasia."

Roebroeks had suggested in a 2005 paper that Asia might have been a core area where Homo erectus emerged, evolving from an earlier, thus far unknown, pre-human.

But he stressed that's a hypothesis which will be tested in future studies. "Possible does not equate with observable, but the Dmanisi evidence has forced us to have a good fresh look at some of our basic assumptions," said Roebroeks.

Homo erectus, heavier, or more robust, than modern humans, and with characteristic brow ridges, is generally listed as having existed from about 1.8 million to 0.3 million years ago. It has some overlap with the earlier Homo habilis and was the first of the species to spread widely outside of Africa.

Not so sure of Ferring and Lordkipanidze's theory is Richard Potts, director of the human origins program at the Smithsonian's National Museum of Natural History.

"The new evidence at Dmanisi consists of stone tools, not fossil bones. So we don't really know who the toolmaker was in the time range of 1.85 to 1.77 million" years ago, he said. "(We) cannot know this for sure until fossils come from this older level."

Michael D. Petraglia, co-director of the Centre for Asian Archaeology, Art & Culture at England's University of Oxford, said the findings do show that early humans were present in Eurasia between 1.85 million and 1.78 million years ago.

"The stone tool evidence represents the oldest and best documented case for the presence of early humans in Asia. This means that early forms of humans probably migrated out of Africa at or before 1.85 million years ago, or before, colonizing new regions of the world for the first time," he said.

But Petraglia added that he thinks the authors "are on less solid ground" with their suggestion that this early group may have migrated back to Africa.

http://news.yahoo.com/s/ap/20110606/ap_on_sc/us_sci_ancient_migration

Hominid females roamed while males waited: study

Julie Steenhuysen

CHICAGO (Reuters) – Females from two hominid species that roamed the South African savannah more than a million years ago left their families and struck out on their own, while their male counterparts tended the home fires, an international team of researchers said on Wednesday.

The findings, published in the journal Nature, came from an analysis of traces of the isotope strontium that had built up in adult teeth from two extinct groups -- Australopithecus africanus and Paranthropus robustus.

Both Paranthropus robustus and Australopithecus africanus were part of a line of close human relatives known as australopithecines that included the Ethiopian fossil, Lucy, estimated to be some 3.2 million years old and regarded by many as the matriarch of modern humans.

To understand how these hominids used the landscape and formed social groups, the team, led by Sandi Copeland of Colorado University Boulder, turned to the ancient dental record.

Using a high-tech analysis known as laser ablation, the team zapped the hominid teeth with lasers to measure ratios of strontium, a naturally occurring element found in rocks and soils that is absorbed by plants and animals.

The team tested 19 teeth dating from roughly 2.7 to 1.7 million years ago from both Australopithecus africanus and Paranthropus robustus individuals from the Sterkfontein and Swartkans cave systems in South Africa.

The team found more than half of the smaller, female teeth came from outside the local area, but only about 10 percent of the male hominid teeth were from elsewhere.

That suggests that males likely grew up and died in the same area, Copeland said.

Copeland said the pattern in which the females left home in search of a mate is similar to chimpanzees and some groups of modern humans, in which a woman leaves her family to join her husband's household.

But it is different from most other primates -- including gorillas -- where the females stay with the group they are born into and the males move elsewhere.

"In any mammal group, including primates, where individuals live in groups, either the females or males must eventually leave their birth community. One of the important reasons for this is to prevent inbreeding," Copeland said.

"In most mammals, it is usually the males that leave their home community," she told a news briefing.

She said the findings were a bit of a surprise.

"We assumed more of the hominids would be from non-local areas since it is generally thought the evolution of bipedalism was due in part to allow individuals to range longer distances," Copeland said.

Such small home ranges suggest that bipedalism evolved for other reasons, she said.

(Editing by Cynthia Osterman)

http://news.yahoo.com/s/nm/20110602/sc_nm/us_science_hominids

Study says use of fire relatively recent in Europe

WASHINGTON (AP) – A new study is raising questions about when ancient human ancestors in Europe learned to control fire, one of the most important steps on the long path to civilization.

A review of 141 archaeological sites across Europe shows habitual use of fire beginning between 300,000 and 400,000 years ago, according to a paper in Tuesday's edition of Proceedings of the National Academy of Sciences.

Most archeologists agree that the use of fire is tied to colonization outside Africa, especially in Europe where temperatures fall below freezing, wrote Wil Roebroeks of Leiden University in the Netherlands and Paola Villa of the University of Colorado.

Yet, while there is evidence of early humans living in Europe as much as a million years ago, the researchers found no clear traces of regular use of fire before about 400,000 years ago.

After that, Neanderthals and modern humans living in Europe regularly used fire for warmth, cooking and light, they found.

"The pattern emerging is a clear as well as a surprising one," they said, considering these ancient people were living in the cold European climate.

Their results raise the question of how early humans survived cold climates without fire. The researchers suggest a highly active lifestyle and a high-protein diet may have helped them adapt to the cold, adding that the consumption of raw meat and seafood by hunter-gatherers is well documented.

Before that period, there is a single site in Israel with earlier evidence of regular fire use, the researchers noted, and there are sites in Africa indicating sporadic fire use.

Not so sure of the late date for controlling fire is Harvard archaeologist Richard W. Wrangham, author of the book "Catching Fire: How Cooking Made Us Human," who argues that learning to cook food — perhaps as much as two million years ago — improved nutrition enough for a burst of evolution promoting development of a bigger brain and, eventually, leading to modern humans.

Wrangham suggested that the lack of earlier evidence of fire could merely mean that, over time, the burned bones or ashes had been destroyed or dispersed.

But Villa, in a telephone interview, said that there is evidence of burned bones in a South African cave from a million years ago, "so burned bones do preserve."

"This paper represents very clearly the archaeological conclusions to what Wil Roebroeks has elegantly called a case of `science friction' resulting from the clash between archaeological and biological evidence," Wrangham wrote in an e-mail.

"So either way we have a lovely puzzle," he said.

Online: http://www.pnas.org

http://news.yahoo.com/s/ap/20110314/ap_on_sc/us_sci_first_fire

的確，我相信「偶然」是人類演變和建立文化的主要推手。但因人有腦力(如記憶力、比較力、以及歸納/演繹的能力等等)，我們得以累積、綜合、分析經驗而成為建立知識和學問。

你說的「『已馴化的』稻米、小麥、狗、馬……。」過程，科學家對它們發生的時間都有概略的推論和估計。此處偶而有報導。只是考古學家每有新的發現，他/她們會將時段上修。目前尚無定論。

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