Stone Age settlement found in English Channel ,Aztec Offerings Found in Bottom of Mexico Lake

Erosion on the floor of the English Channel is revealing the remains of a busy Stone Age settlement, from a time when Europe and Britain were still linked by land, a team of archaeologists says.

The site, just off the Isle of Wight, dates back 8,000 years, not long before melting glaciers filled in the Channel and likely drove the settlement's last occupants north to higher ground.

"This is the only site of its kind in the United Kingdom," said Garry Momber, director of the Hampshire and Wight Trust for Maritime Archaeology, which led the recent excavations. "It is important because this is the period when modern people were blossoming, just coming out of the end of the Ice Age, living more like we do today in the valleys and lowlands."

Lobsters mucking around the seabed at the site about 10 years ago revealed a cache of Mesolithic flints, prompting further excavations that uncovered two hearths (ancient ovens) dangling precariously from the edge of an underwater cliff.

Burnt wood fragments gouged with cut marks and a layer of wood chippings were found lying under 35 feet of water during the latest dig. Divers brought the material to the surface still embedded in slabs of the sea floor that were carried up in specially-designed boxes, which were then pieced back together and examined and dated in the lab.

We now have unequivocal evidence of human activity at the site," Momber told LiveScience. "There were people here actively making stuff and being quite industrious."

At 8,000-years-old, the settlement is the only underwater Mesolithic site in Britain, though it is probably part of a much larger area of occupation yet to be uncovered, Momber said.

As the climate began to warm up near the end of the Ice Age about 10,000 years ago, people were moving into Northern Europe and settling down in the many river valleys left behind by melting glaciers, Momber explained. Many of the valleys, such as the ones now beneath the English Channel, were eventually inundated completely when temperatures returned to normal.

"A good chunk of the material left behind from this cultural period is eventually going to be found underwater," Momber said.

Underwater sites better preserved
Despite the logistical problems of underwater archaeology, the Isle of Wight site and others like it are usually better preserved than their counterparts on land, Momber said.

When the floodwater rose slowly in the English Channel, it deposited layers of silt atop the settlement, encasing it in an oxygen-free environment that preserves even organic materials such as wood and food.

Aztec Offerings Found in Bottom of Mexico Lake

MEXICO CITY - Archaeologists diving into a lake in the crater of a snowcapped volcano found wooden scepters shaped like lightning bolts that match 500-year-old descriptions by Spanish priests and conquerors writing about offerings to the Aztec rain god.

The lightning bolts - along with cones of copal incense and obsidian knives - were found during scuba-diving expeditions in one of the twin lakes of the extinct Nevado de Toluca volcano, at more than 13,800 feet above sea level.

Scientists must still conduct tests to determine the age of the findings, but the writings after the Spanish conquest in 1521 have led them to believe the offerings were left in the frigid lake west of Mexico City more than 500 years ago.

Lightning bolt scepters "were used by Aztec priests when they were doing rites associated with the god Tlaloc," said Johan Reinhard, an anthropologist and explorer-in-residence for National Geographic Society who took part in more dives Thursday at the Lake of the Moon. "We think it is pretty clear that the Aztecs considered this one of the more important places of Tlaloc."

The research, which also involves the volcano's Lake of the Sun, is being led by Mexico's National Institute of Anthropology and History. Stanislaw Iwaniszewski, an archaeology professor at the institute, said Aztec iconography often associates Tlaloc with lightning bolts.

"They were left in the lake to bring rain storms," Iwaniszewski said. Copal incense was burned to form "clouds," and sharp spines from the maguey cactus - which does not grow at that altitude - indicated worshippers brought them there to draw blood from themselves as part of the sacrifice.

Luis Alberto Martos, the institute's director of archaeological studies, said other artifacts found in the clear 32-degree waters of the lake indicate the ritual may have started about 100 B.C. - long before the Aztecas settled in the area in 1325.

Technorati : Stone Age

New fossil research challenges old Homo evolution theory

New research of fossils discovered in Africa challenges the old theory on how early humans evolved, according to Thursday's journal Nature.

The research by famed paleontologist Maeve Leakey in Kenya shows our family tree is more like a wayward bush with stubby branches, calling into question the evolution of our ancestors.

In 2000, Leakey found an old Homo erectus complete skull within walking distance of an upper jaw of the Homo habilis, and both dated from the same general time period. That makes it unlikely that H. erectus evolved from Homo habilis, researchers said.

The old theory was that the first and oldest species in our family tree, Homo habilis, evolved into Homo erectus, which then became us, Homo sapiens.

Leakey and colleagues reported in Nature that those two earlier species lived side-by-side about 1.5 million years ago in parts of Kenya for at least half a million years.

This discredits the chief theory of man's early evolution - that one of those species evolved from the other.

The two species lived near each other, but probably didn't interact, each having its own "ecological niche," said Fred Spoor, a professor of evolutionary anatomy at the University College in London. "Homo habilis was likely more vegetarian while Homo erectus ate some meat," he said.

For the past few years there has been growing doubt and debate about whether Homo habilis evolved into Homo erectus. Scientists still have different opinions about it.

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Surprising research based on two African fossils suggests our family tree is more like a wayward bush with stubby branches, challenging what had been common thinking on how early humans evolved.

The discovery by Meave Leakey, a member of a famous family of paleontologists, shows that two species of early human ancestors lived at the same time in Kenya. That pokes holes in the chief theory of man's early evolution - that one of those species evolved from the other.

And it further discredits that iconic illustration of human evolution that begins with a knuckle-dragging ape and ends with a briefcase-carrying man.

The old theory is that the first and oldest species in our family tree, Homo habilis, evolved into Homo erectus, which then became human, Homo sapiens. But Leakey's find suggests those two earlier species lived side-by-side about 1.5 million years ago in parts of Kenya for at least half a million years. She and her research colleagues report the discovery in a paper published in Thursday's journal Nature.

The paper is based on fossilized bones found in 2000. The complete skull of Homo erectus was found within walking distance of an upper jaw of Homo habilis, and both dated from the same general time period. That makes it unlikely that Homo erectus evolved from Homo habilis, researchers said.

It's the equivalent of finding that your grandmother and great-grandmother were sisters rather than mother-daughter, said study co-author Fred Spoor, a professor of evolutionary anatomy at the University College in London.

The two species lived near each other, but probably didn't interact, each having its own "ecological niche," Spoor said. Homo habilis was likely more vegetarian while Homo erectus ate some meat, he said. Like chimps and apes, "they'd just avoid each other, they don't feel comfortable in each other's company," he said.

There remains some still-undiscovered common ancestor that probably lived 2 million to 3 million years ago, a time that has not left much fossil record, Spoor said.

Overall what it paints for human evolution is a "chaotic kind of looking evolutionary tree rather than this heroic march that you see with the cartoons of an early ancestor evolving into some intermediate and eventually unto us," Spoor said in a phone interview from a field office of the Koobi Fora Research Project in northern Kenya.

That old evolutionary cartoon, while popular with the general public, is just too simple and keeps getting revised, said Bill Kimbel, who praised the latest findings. He is science director of the Institute of Human Origins at Arizona State University and wasn't part of the Leakey team.

"The more we know, the more complex the story gets," he said. Scientists used to think Homo sapiens evolved from Neanderthals, he said. But now we know that both species lived during the same time period and that we did not come from Neanderthals.

Now a similar discovery applies further back in time.

Susan Anton, a New York University anthropologist and co-author of the Leakey work, said she expects anti-evolution proponents to seize on the new research, but said it would be a mistake to try to use the new work to show flaws in evolution theory.

"This is not questioning the idea at all of evolution; it is refining some of the specific points," Anton said. "This is a great example of what science does and religion doesn't do. It's a continous self-testing process."

For the past few years there has been growing doubt and debate about whether Homo habilis evolved into Homo erectus. One of the major proponents of the more linear, or ladder-like evolution that this evidence weakens, called Leakey's findings important, but he wasn't ready to concede defeat.

Dr. Bernard Wood, a surgeon-turned-professor of human origins at George Washington University, said in an e-mail Wednesday that "this is only a skirmish in the protracted 'war' between the people who like a bushy interpretation and those who like a more ladder-like interpretation of early human evolution."

Leakey's team spent seven years analyzing the fossils before announcing it was time to redraw the family tree - and rethink other ideas about human evolutionary history. That's especially true of most immediate ancestor, Homo erectus.

Because the Homo erectus skull Leakey recovered was much smaller than others, scientists had to first prove that it was erectus and not another species nor a genetic freak. The jaw, probably from an 18- or 19-year-old female, was adult and showed no signs of malformation or genetic mutations, Spoor said. The scientists also know it isn't Homo habilis from several distinct features on the jaw.

That caused researchers to re-examine the 30 other erectus skulls they have and the dozens of partial fossils. They realized that the females of that species are much smaller than the males - something different from modern man, but similar to other animals, said Anton. Scientists hadn't looked carefully enough before to see that there was a distinct difference in males and females.

Difference in size between males and females seem to be related to monogamy, the researchers said. Primates that have same-sized males and females, such as gibbons, tend to be more monogamous. Species that are not monogamous, such as gorillas and baboons, have much bigger males.

This suggests that our ancestor Homo erectus reproduced with multiple partners.

The Homo habilis jaw was dated at 1.44 million years ago. That is the youngest ever found from a species that scientists originally figured died off somewhere between 1.7 and 2 million years ago, Spoor said. It enabled scientists to say that Homo erectus and Homo habilis lived at the same time.

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