What`s Afoot 3
GENEVA, Aug 30 1998 (Reuters) - Dinosaur tracks discovered on a cliffside in Bolivia show that many species of the creatures that ruled the earth for millions of years lived side by side, according to a Swiss palaeontologist. Christian Meyer of the University of Basle, just back from the site of Cal Orcko near the city of Sucre, told the newspaper Le Matin that it was a ‘dinosaur El Dorado’ and probably the world’s most important site for their study. Meyer said the some 3,000 footprints making up 250 different tracks over the cliff face of 25,000 square metres dated from 6 8 million years ago, or three million years before dinosaurs were wiped out, apparently when a vast meteor hit the planet. ‘The most extraordinary thing is the diversity of the species represented and the fact that they all date back to the same period, ’ he told the newspaper.
Tracks identified included those of a meat-eating therapod that could grow up to seven metres long, a lumbering titanosaurus which measured 15 to 25 metres, a smaller, armoured ankylosaurus, and vegetarian ornithopods which walked on two feet. ‘The whole carnival, the whole range is there, ’ said Meyer. ‘This is the first site which makes it possible to show that these species lived at the same time and in the same place until just before their extinction. ‘ Many other dinosaur tracks have been found around the world, especially in the mid-West of the United States in the Rocky Mountains and some in Switzerland high in the Alps near the border with France and Italy east of Mont Blanc. But at the Bolivian site, Meyer said, the number and variety of prints was the greatest yet discovered. One theropod track was 350 metres long. Some prints left by the larger dinosaurs - first identified as a common group in 1841 by early British palaeontologist Richard Owen - were 60 cm across. The area of the Bolivian site was once covered by a vast freshwater lake. The dinosaur tracks were made along its shores in heavy mud which then solidified and filled with loose shale, as in similar sites elsewhere. Later volcanic activity raised the bank, turning it into a towering cliff whose local name means ‘Chalk Mountain.‘
Meyer said the tracks were first found in the early 1980s by workers at a local cement quarry, but it was not until 1994 that a Bolivian geologist identified them as dinosaur footprints. The 42-year-old scientist, with a grant from Switzerland’s National Fund for Scientific Research and backing from private sponsors, led a 15-member international team to carry out a full survey of Cal Orcko over six weeks in July and August. He said they had made silicone copies of the most interesting prints, using mountaineering techniques to scale the sheer cliff face. Another discovery in the area was the fossil of a flying reptile 40 cm long. Most palaeontologists now believe that smaller dinosaur survivors of the meteor holocaust 65 million years ago evolved into birds.
They come from the land of the Ice and Snow, with the midnight sun and the hot springs blow...oh Hammer of the Gods...
SCIENCE TODAY 12 Oct 1998 - DNA hunters unravel Viking meat source Viking raiders who settled Dublin over 1,000 years ago did not bring along their own livestock; they helped themselves to the local Irish cattle, according to new studies of ancient animal DNA recovered from Wood Quay. The Vikings by all Hollywood accounts enjoyed their grog and meat. Whatever about their drinking habits, excavations at the Wood Quay site at the foot of Christ Church Cathedral, Dublin, did show that they liked their beef. The site was littered with the remains of feasts past, according to Dr David MacHugh, of the archaeological genetics department at the Smurfit Institute of Genetics, Trinity College. Bones were some of the most plentiful remains found at Wood Quay. A collaborative effort involving geneticists and archaeologists from Trinity and Queen's University Belfast set out to determine the origin of these bones.
The object of the Wellcome-funded study, Dr MacHugh explained, was to establish whether the animals were brought to Ireland on Scandinavian galleys delivering a taste from home or if they were herded or plundered locally. Their work will be published in the December issue of Philosophical Transactions: Biological Sciences. Ireland was an ideal location to do ancient DNA work, he said. The climate was conducive for the survival of DNA in archaeological remains, and the bones, dated to just over 1,000 years, were well within the accepted 10,000-year limits for ancient DNA hunters. The bones were taken from soggy riverside soils, but this thwarted biological breakdown, Dr MacHugh said. ‘They were in anoxic conditions so there was very little bacterial growth or damage. ’ When the bones were collected in the late 1970s and 1980s they were measured and examined but the ability to study the animals' genetic make-up, their genetic fingerprint, was yet to be introduced, he said.
The team used the latest genetic techniques including polymerase chain reaction (PCR) amplification of mitocondrial DNA. They compared the DNA in Wood Quay samples with samples collected from modern Irish (including Kerry cows), Norwegian and Icelandic cattle breeds, to determine the origins of the medieval beef. PCR was a highly demanding method for retrieving DNA, Dr MacHugh said. It could isolate a single DNA fragment and then replicate it a million-fold to a point where its genetic sequence could be studied in detail. Success required elaborate safeguards to protect against accidental contamination, however. While DNA from the cell nucleus could sometimes be retrieved, ancient DNA hunters frequently isolated DNA from the cell's mitochondria because mitocondrial DNA was more plentiful, Dr MacHugh explained. While there was one nucleus in the cell there could be many hundreds of mitocondria, each offering the possibility of a viable DNA sample. Even so only 11 of the 22 bone samples examined had DNA available for PCR amplification, he said. Generally, the older the bones the lower the success rate.
The bone samples were first sand-blasted to clean away centuries of dirt and contamination and then exposed to strong ultraviolet light to sterilise their surfaces. A bone sample was then taken and powdered and any available DNA was identified and sequenced. One might have expected the incoming Vikings to have brought some of their own native cattle, but there was no evidence of this in the bones under study, Dr MacHugh said.
The new arrivals were happy to take or trade for what was available locally. The cattle bones recovered at Wood Quay were not far removed genetically from today's animals, however. ‘They were very similar to modern European cattle. This would suggest that the diversity found in modern cattle arose 5,000 years ago when cattle first appeared in Europe. ‘However, some level of genetic shift was apparent. The Wood Quay remains ‘seemed to have some [DNA] sequences that were not present in modern breeds’, Dr MacHugh said. These could have been lost through spontaneous change or susceptibility to disease that eliminated certain cattle groups. The research effort is ongoing with cattle breeds from Spain and Portugal being added for comparison.
The 12-strong Trinity group is also examining ancient human DNA and horse and salmon DNA, looking in particular at differences between farmed and wild salmon. Bones from the now extinct ancient Irish elk are also being studied to see if they are related to modern deer.
The Independent - 31 August 1998
Daddy I hardly knew you
Scientists may have found the direct descendants of one of the first tribes of early humans to emerge out of Africa about 100,000 years ago.
The discovery promises to shed light on one of the most enigmatic periods in early human history, when the first people colonised the world, eventually leading to Homo sapiens becoming the only species to dominate every corner of the globe.
Locks of hair stored at Cambridge University for the past 90 years have revealed DNA evidence to link the inhabitants of the remote Andaman Islands with the first anatomically modern humans to migrate across Asia. The Andamanese were living a stone-age existence when Western explorers in the 19th century made contact. An analysis of their genetic make up indicates they could be a lost tribe that has remained isolated from other humans for many thousands of years.
DNA analysis has shown that in spite of the wide variation in the physical features of ethnic groups today, we are more closely related to each other than most other species of mammals.
Scientists believe only a small number of our ancestors - perhaps no more than a few thousand - crossed the Sinai peninsula to populate Asia, Europe, Oceania and the Americas.
The genetic ‘bottleneck’ caused by having so few ancestors resulted in humans today being relatively inbred. Studies into the sequence of letters’ in the genetic code of different ethnic groups - analysed from blood samples - have nevertheless been able to guide scientists to the most ancient lineages of DNA that date back to this early period of human history.
Dr Erika Hagelberg, a geneticist at Cambridge University, and Dr Carlos Lalueza Fox, from the University of Barcelona, have extracted enough DNA from the hair of 42 people to compare the genetic relationship of the Andamanese with other ethnic groups around the world.
One particular mutation, where a tiny stretch of DNA is deleted, shows that the Andamanese, who live in the Bay of Bengal south of Burma, do not share their pattern of inheritance with other Asians. ‘The significance of this mutation is that it seems to be associated with the more recent population explosions linked with the development and spread of agriculture about 6 ,000 to 8,000 years ago,’ said Dr Hagelberg.
‘It looks like the Andamanese are the descendants of a much earlier hunter-gathering group of humans who did not have any later contact with the agricultural people and who were therefore not part of the subsequent population explosion out of Africa and across the Asian continent.‘
Agriculture is a recent innovation in human history, with the earliest indications of it appearing in the fertile crescent of the Middle East about 10,000 years ago. It is widely assumed that the agricultural revolution spread across the rest of Europe and Asia either by hunter-gathering communities dying out, or by their conversion to farming.
The Andamanese may prove to be one of the few people alive today with a truly ancient genetic lineage dating directly to the earliest human migrations across Asia. The Andaman islanders may owe their unique genetic makeup to their fierce reputation and to geographical isolation. They live in densely forested mountains and have a history of killing any foreigners who stray into their territory. They traditionally live by hunting wild pigs, fishing and collecting fruit, berries and nuts. One of their most unique cultural features is that they had no method of making fire. Their language is also unique, having no relationship with the tongues of neighbouring populations.
Their only indigenous weapon is the bow, which the Andamanese use for both hunting and fishing from dug-out canoes. They have no traps and have never discovered how to make fishhooks.
Anthropologists have long been unable to classify the Andamanese -their physical appearance is neither caucasian nor mongoloid - and gave them the name ‘negrito’ because of their dark skin and pygmy stature.
The Andamanese hair samples at Cambridge are part of the Duckworth collection made by the great explorer and early anthropologist, A. R. Radcliffe-Brown, one of the first Western scholars to study the islanders. Dr Hagelberg said the hair samples represented a unique genetic resource because they date to a period just after the islanders were contacted and therefore had not suffered any ‘genetic dilution’ resulting from intermarriage with outsiders.
‘Our results indicate that the Andamanese are the descendants of one of the earliest expansions of anatomically modern humans. They appear more closely related to southern African pygmies than to other Asian groups. They are, in effect, the descendants of the earliest migrations of Homo sapiens out of Africa, ’ she said.
The present-day Andamanese are in decline, being highly susceptible to illnesses to which they have no immunity, and from pressure on their native forests from logging companies.
More of the same - sort of
DNA Study Shows NZ Maoris Come from Taiwan
WELLINGTON (10 Aug 1998) XINHUA - The ancestors of Maoris, the native people in New Zealand, and the other Polynesian peoples, were migrants from Taiwan, according to research conducted with new techniques for analysing human DNA.
The people who eventually became the Maoris originated in mainland Asia and, starting from Taiwan, island-hopped their way through the Philippines and Indonesia to West Polynesia and ultimately on to the islands of East Polynesia and then New Zealand, Wellington's Victoria University scientist Geoffrey Chambers said in a research report published Monday by the university.
‘There is an exact living record of these voyages of colonisation, preserved in the DNA of their modern-day descendants who are still living in these places along the route, ’ a Wellington-based newspaper quoted Chambers as saying.
The Evening Post also quoted Chambers as saying forensic DNA profiles carried out at Victoria University had also found that Polynesians in general and New Zealand Maoris in particular showed less genetic diversity than many other ethnic groups.
The overall probability of finding two individuals with a specific DNA profile was found to be one in 112 million for Asians, one in 47 million for Caucasians, one in 6 . 7 million for Polynesians and one in 2. 8 million for Maoris.
Electronic Telegraph Monday 22 June 1998
HOOLIGANS have prompted South African scientists to plan a helicopter rescue of ‘Eve's Footprints’, believed to be the world's oldest human foot-marks, on rocks on the Cape west coast.
The prints, estimated to be 117,000 years old, have drawn day trippers since their discovery last year by Dave Roberts, of South Africa’s Council for Geoscience, and Lee Berger, an American palaeo-anthropologist. With the assistance of British and American conservationists, the Council for Geoscience will attempt to cut the fragile rock in which the footprints are embedded and airlift the entire chunk by helicopter to Cape Town.
Mike van Weiringen, a geologist, said: ’This is a world first. No case study exists internationally to guide us. No one has yet bench-marked the removal of a fossil embedded in brittle dune rock so exposed to wave action and atmospheric weathering, but we are confident that our operational plan is sound. ‘
If successful, the operation could be repeated with other valuable fossil finds under threat from hooligans and the elements. In the case of ‘Eve's Footprints’, the South African Museum will make replicas to replace the originals at the site.
Attempts to supervise visitors to the site, a remote dune rock bed on the Langebaan Lagoon 50 miles north-west of Cape Town, failed to stop hooligans inscribing the rocks with graffiti, putting their own feet into the fossilised footprints and even attempting to remove parts of the footprints.
The marks were named Eve's Footprints by scientists who determined that they were the fossilised marks of a female hominid and tended to confirm the increasingly held belief that man originated in southern Africa.
How oldis the Med?
How old is old in the Mediterranean? Scientists hope tree rings will tell. 27 Sept 1998
ITHACA, N.Y. (AP) - In a basement laboratory at Cornell University, scientists are using chunks of wood to revolutionise the study of ancient history in the eastern Mediterranean. They're gathering tree rings for every year back to 7500 B.C. - every single year.
The payoff? A way to determine the age of wood or charcoal from archaeological sites, right to the year that the tree toppled.
It won't always be that precise. But for archaeologists who are now delighted if they can date artefacts at give-or-take 50 years, the prospect is astounding. Some accepted dates for historical events might shift by as much as 100 years. Movements like that - and the very precision of the dating technique - could overturn ideas about trade, migrations, wars and whether particular trends were evolutions or revolutions.
‘It's going to completely change our understanding of the chronological sequences of the Aegean and Near East, ’ said one observer, archaeologist Gil Stein of North-western University. ‘We will really know when these sites were occupied, when these styles of pottery were used, when these cities arose, when these areas were abandoned — very important things that up until now have been very much subject to debate.‘
And all this for a time when Pharaohs ruled, the world's first major cities arose and collapsed, civilisations took root in Egypt and Mesopotamia, and classical Greece and Rome appeared and disintegrated.
At the center of the tree-ring effort is Peter Ian Kuniholm, 60, a husky classical archaeologist who minces no words. He can dismiss a misguided analysis as ‘sheer howling nonsense’ and a clutch of Byzantine samples as ‘major site, cruddy wood.‘
Kuniholm began the work 25 years ago, and he knows his stuff. During a recent chat in his lab he spoke in encyclopaedic detail. He repeatedly bolted from his chair in mid-conversation to fetch a phrase from the middle of an inch-thick file, a chunk of poplar from the Parthenon or purchasing records - in drachmas -of an ancient temple treasurer.
He's not the first person to use tree rings for establishing dates. Such ‘dendrochronology’ has been applied to thousands of years of history in Europe and the American Southwest, for example. But some colleagues initially scoffed at Kuniholm's attempt to apply it to the eastern Mediterranean, which is not exactly covered with forests.
‘I kept saying to him in the early days, `Well, Peter, where are you going to find wood?' (It seemed) like counting blades of grass in the Sahara, ’ recalled archaeologist Curtis Runnels of Boston University. ‘He had faith where the rest of us had doubts. ‘
Site by site, chunk by chunk, some 30,000 wood samples have been collected from about 600 sites in 18 countries, including Italy, Greece, Yugoslavia, Bulgaria, Turkey, Cyprus, northern Syria and Lebanon. The samples have included a piece of an ancient Turkish coffin lid, boxwood from a first-century-B.C. Roman boat, and scorched timbers from a carpenter's workshop - smothered by the eruption of Mount Vesuvius in 79 A. D.
Kuniholm's lab has made more than 9 million microscope measurements of tree rings, some finer than a human hair. Even a finger-sized piece of wood can hold enough rings to be useful, and a sample the size of a pizza slice can present a bounty of 750 rings.
Here's how the analysis works:
Trees add a ring each year, sometimes thin, sometimes thick, depending on growing conditions. ‘When I have cool, wet summers my trees grow like gangbusters, ’ Kuniholm said.
If a series of years provides a sequence of growing conditions like poor-poorer-average-great-poor-average, those years should produce a sequence of rings something like thin-thinner-average-thick-thin-average. And if two trees share the same climate, that imprint should be left on both of them, even if one is young and the other quite old.
So when Kuniholm and his assistants analyse a piece of wood, they see if its tree ring sequence matches one already in the database. If there’s a close-enough match between two long sequences — generally 100 rings long at least — the two trees were alive during the same years. And if the new wood piece has bark, Kuniholm knows it was cut in the year represented by the last ring.
But what year was that ? Kuniholm can tell, so long as the tree was felled after 36 0 A. D. His database reaches backward to that date, starting with ring patterns from contemporary trees — which can be dated with certainty — and extended by sequences from older wood samples. When a sample matches the oldest rings in the database and provides still older rings, the older rings can be dated and the database extended.
It's this process that Kuniholm hopes to push all the way back to 7500 B. C.
Even now, he says he can date wood from 2660 B.C. to 627 B.C. , if he’s right in asserting that a volcano erupted on the Aegean island of Thera in 1627 B.C. and that a particularly thick ring in his samples corresponds to that event.
Tree rings can't date every piece of wood precisely. If there’s no bark or other unambiguous sign that the last ring marked the death of the tree, Kuniholm can say only that the tree was living during certain years, but not when it was chopped down. And even if analysis does reveal a precise date on a beam from a building, that doesn't always say how old the building is. The wood might have been re-used from some previous building, or newly cut to repair an old building.
All told, the lab database includes tree ring segments covering about 6 , 500 years. But most segments are floating in time, not precisely datable until the database reaches back far enough back to include them.
So, to get more wood, Kuniholm and assistants typically drive 10,000 miles a summer, visiting digs and museums, making their faces known, handing out scientific articles and brochures in eight languages — anything to locate samples and spread the word of their quest. ‘Everybody is rushing to bring him wood, ’ said anthropologist Mary Voigt of the College of William & Mary. ‘It's clear he has a long-enough sequence that we have some confidence in the dates. ‘
She hopes Kuniholm can help her analyse ruins at Gordion, the Turkish home of King Midas: that's where Kuniholm began his project, out of frustration with the imprecision of other methods.
Decades later, it's still fun.
He once visited a stone castle at Pythion, on the border of Greece and Turkey. The archaeologist there could say only that it was built in the first half of the 14th Century, based on pottery, coins and written histories.
Kuniholm rappelled down its face and fished out some rotted timber, which the ancient builders had used as scaffolding.
‘The wood was all cut in 1331, ’ Kuniholm said the other day with obvious satisfaction. ‘He can give me within 50 years. I can tell him the year. ‘
Tar Very Much
Tar Ranch: (AP)
Step carefully down the ladder into the black, oozing pit 13 feet below the bustling heart of Los Angeles and you're staring into a treasure trove of Ice Age animals that literally sank into history. Mammoths and mastodons, sabre-tooth cats and dire wolves, camels and bison, land sloths and land snails became ensnared by sticky asphalt that migrated upward through cracks and fissures from the Salt Lake Oilfield 1,000 feet down. Millions of their bones have been extracted from the world-famous La Brea Tar Pits, wedged between museums, office buildings and condo towers in the middle of the bustling Wiltshire-Fairfax district. They're not really pits, but murky puddles of water, seeping asphalt and bubbling methane that dot the only Ice Age fossil excavation site inside a major metropolitan area.
Rancho La Brea - Spanish for ‘the tar ranch’ - is more than just a tourist stop on the way to Hollywood or a school field trip. It's a renowned scientific resource. ‘It's the standard for life in North America in the last phase of the Ice Age, ’ says John Harris, chief curator and head of palaeontology at the Page Museum of the La Brea Tar Pits, part of the Los Angeles Museum of Natural History. The site also tells climate experts that Los Angeles during the Ice Age was more like San Francisco, cooler by 5 or 6 degrees, with summer and winter rain. ‘It is a very nice window on the fauna and to some extent the flora that was present in the Los Angeles Basin’ from about 40,000 to 10,000 years ago, says Ernie Lundelius, a geology professorat the University of Texas. ‘No other place in the world has these extinct animals as well-preserved and in such abundance, ’ says William A. Akersten, a former supervising curator of Rancho La Brea. ‘You can do statistical analyses of sabre-tooth cats (because) you have maybe 1,000 individuals. No other place do you have more than two or three.‘
Rancho La Brea features 650 species, many extinct, and the remains of 9,000-year-old La Brea Woman. Her partial skull suggests a blow to the head that may make her L.A.'s earliest homicide. Asphalt is the crudest of petroleum products and a remarkable preservative that fills the tiny pores of bones. It's so effective that it has protected bird bones that commonly disintegrate. Washing away most of the asphalt with solvents leaves behind a stunning sheen. The asphalt deposits were shallow self-baiting traps that acted ‘like flypaper spread over the surface, ’Harris says. ‘It only takes 1 1/2 inches of asphalt to totally immobilise an animal the size of a cow. ‘ Once a large grazing animal got stuck, meat-eating predators would approach and get trapped, followed by the scavengers and insects that feasted on rotting remains.
‘Pretty soon, you've brought up the whole food chain, ’Harris says. In summer, warm asphalt flowed over the remains. During winter rains, streams deposited silt and sand atop the asphalt. Eventually, cone-shaped deposits buried the bones. Last week, on one of year's hottest days _ when the asphalt was warm and viscous, the Page Museum opened Pit 91 to reporters. At the bottom, blackened bones criss-cross like a child's game of pick-up sticks _ a femur jutting out here, a skull there. Protected by an overhead tarpaulin, volunteer excavators perched on wooden planks scrape away the rough mixture of asphalt, sand, seeds, leaves, twigs and ancient insect parts that clings to bones about 28,000 years old. They work one 3-foot-by-3-foot grid at a time, using dental tools, brushes, chisels and screwdrivers to define the bones, said Meghan Howard Meyer, 27, as she removed asphalt around two sabre-tooth cat skulls. ‘I love getting a gooey bone to work on, ’ said Karolyn Knoll, 20, a geology student at the University of Wisconsin at River Falls. The two showed off the day's find, a tiny dermalossicle, one of the protective bones embedded in the fur and skin of the giant ground sloth that would give any biting predator pause.
A few yards from the excavation, volunteer guide Ellen Bernick made sure to correct visitors' misimpression about the tar pits from the movie ‘Volcano, ’ in which a fictional volcano erupted at the site. ‘We don't erupt, we seep, ’ Ms. Bernick said. Nonetheless, the movie drew Rachel Sturdy, 13, of Warrenton, Va. , and her family for a visit. Rachel described the tar pits as ‘pretty cool. ‘ She and other kids got to glimpse some of the work going on under the supervision of Shelley Cox inside the museum's palaeontology laboratory. that 's where fossils are cleaned, sorted, and identified. Fitting together bone fragments from among hundreds is a matter of matching up ‘kibbles and bits, ’ Ms. Cox says. The tools are deceptively simple, glue and a keen eye. Besides collecting and cataloguing, some research is being carried out. Harris and colleagues from Duke University and the University of California, Los Angeles, have a $150,000 National Science Foundation grant to study how fossils accumulated at Rancho La Brea. But Akersten, now curator of fossil vertebrates at the Idaho Museum of Natural History, says more could be done if the county and the museum paid more attention. ‘It's never had a chance to come anywhere near its potential, ’ Akersten said. ‘What needs to be done now is more sophisticated . . . and it's kind of in a holding pattern unless funding is developed.‘ He's also upset that local politics allowed the Los Angeles County Museum of Art to pave over a corner of the property: ‘There’s hundreds of art museums. There’s only one Rancho La Brea.‘