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Excavation Of Teeth From First Africans
Upper incisor teeth recovered from the grave in Campeche, Mexico, show evidence of filing, a distinctive practice of some 16th-century Africans.
Photo Credit: Courtesy T. Douglas Price
"It does mean that slaves were brought here almost as soon as Europeans arrived," said T. Douglas Price of the University of Wisconsin-Madison. Price and coworker James H. Burton of UW-Madison, and Vera Tiesler of the Autonomous University of the Yucatan, measured a radioactive substance known as strontium in teeth recovered from an early colonial burial ground in Campeche, Mexico, located on the gulf shore of the Yucatan Peninsula. Strontium isotopes are normally found in the soil, but make their way into the food supply when they are dissolved and taken up by plants. Because the substance concentrates in teeth and bones of people and animals that eat the plants, strontium has become a reliable marker not only of the age of human remains but also of their geographic origin. The National Science Foundation funded the work. Radioactive strontium in teeth is especially useful for determining birthplace, because teeth form during gestation and early childhood. The type of strontium found in teeth mirrors that deposited in the bedrock of the area where a person was born. By comparing the isotopes in teeth recovered from the graveyard with known strontium values for geologic regions around the world, the researchers were able to determine if the individuals were born in Africa or the New World......... Posted by: William Permalink Universities And Internet
"The Internet, which a number of people view as the most important technology of the last 15 years, moved from universities to the public in an unusual way," says Avi Goldfarb, a professor at the University of Toronto's Joseph L. Rotman School of Management. He points out that there has been little empirical research on the role of universities in diffusing technology. "Most technologies that are invented in universities move through research journals or through business partnerships. The Internet followed a different pattern, in that students brought it to the public". Goldfarb analysed data from nearly 105,000 surveys and found that even when controlling for factors like age, industry and tech-savviness, the impact of a mid-1990s university education on Internet use was much higher than for other time periods. The effect is not limited to students from that period, but has been transferred to members of their households, regardless of age. "In other words, universities taught a generation of students to use the Internet and they in turn taught their families". Source: University of Toronto........ Posted by: Kevin Permalink Source Ancient Origin Of Vertebrate Skeleton
Sea Lamprey
It turns out lampreys, long thought to have taken a different evolutionary road than almost all other backboned animals, may not be so different after all, particularly in terms of the genetics that govern their skeletal development, as per findings would be published online this week in the Proceedings of the National Academy of Sciences. UF researchers found the same essential protein that builds cartilage in this odd animal - it spends the first five years of its development in the larval stage before it finally morphs into a boneless fish - is none other than collagen. This vital structural molecule is found in all vertebrates with backbones and jaws, including humans. "It was thought collagen was a relatively recent invention in vertebrate evolution that unites us with reptiles, amphibians, sharks and bony fishes, while the lamprey skeleton was based on quite different proteins," said Martin Cohn, Ph.D., a developmental biologist and associate professor with the UF departments of zoology and anatomy and cell biology. "Knowing that lampreys also use collagen to build their skeletons makes sense. Lampreys and jawed vertebrates inherited the same genetic program for skeletal development from our common ancestor."........ Posted by: Ashley Permalink Source Fossil Named After Artist Georgia O'Keeffe
Sketch courtesy of Sterling Nesbitt.
The new finding is described in the journal Proceedings of the Royal Society B by Sterling J. Nesbitt, a graduate student enrolled at Columbia University who studies at the American Museum of Natural History and also is affiliated with the Columbia's Lamont-Doherty Earth Observatory, and Mark A. Norell, Curator in the Museum's Division of Paleontology, who is also an adjunct professor of earth and environmental sciences at Columbia. They have have named the fossil Effigia okeeffeae. Effigia means "ghost," referring to the decades that the fossil remained hidden from science. The species name, okeeffeae, honors the artist Georgia O'Keeffe, who lived near the site in northern New Mexico where the fossil was found. Researchers say Effigia is a striking example of "convergence," when two lineages evolve the same body plan. "It is astounding to see so a number of advanced dinosaur features in an animal so closely correlation to modern crocodiles, Norell said. Obviously, this group of crocodiles and dinosaurs must have had similar habitats and probably fed in the same way, accounting for the similarities of the limbs and skull"......... Posted by: William Permalink Source Oceans May Soon Be More Corrosive Compare To The Time Dinosaurs Died
Caldeira's computer models have predicted that the oceans will become far more acidic within the next century. Now, he has compared this data with ocean chemistry evidence from the fossil record, and has found some startling similarities. The new finding offers a glimpse of what the future might hold for ocean life if society does not drastically curb carbon dioxide emissions. "The geologic record tells us the chemical effects of ocean acidification would last tens of thousands of years," Caldeira said. "But biological recovery could take millions of years. Ocean acidification has the potential to cause extinction of a number of marine species." When carbon dioxide from the burning of coal, oil, and gas dissolves in the ocean, some of it becomes carbonic acid. Over time, accumulation of this carbonic acid makes ocean water more acidic. When carbonic acid input is modest, sediments from the ocean floor can buffer the increases in acidity. But at the current rate of input--nearly 50 times the natural background from volcanoes and other sources--this buffering mechanism is overwhelmed. Prior estimates suggest that in less than 100 years, the pH of the oceans could drop by as much as half a unit from its natural value of 8.2 to about 7.7. (On the pH scale, lower numbers are more acidic and higher numbers are more basic.)......... Posted by: Tyler Permalink About Early Human Ancestors
It seems some of our earliest ancestors possessed a rather unsteady stride due to subtle anatomical differences. Schwartz and Gebo's findings would be reported in the April 2006 edition of the American Journal of Physical Anthropology, but the article is available online at www3.interscience.wiley.com/cgi-bin/abstract/112169244. Schwartz and Gebo looked at seven anklebones from a variety of early human ancestors found in eastern and southern Africa and compared them to samples taken from modern humans, chimpanzees and gorillas. The research led them to two significant conclusions. First, certain ancestral anklebones that were thought by some to be "half ape, half human" were found to be much more similar to humans, confirming these specimens were obligate bipeds--in other words, they most likely walked on two feet in a manner similar to how we walk today. The second discovery was that eventhough the samples were certainly from bipeds, there were structural differences in some of the anklebones that indicated they would have walked a little differently than modern humans. Specifically, an ancestral species usually referred to as robust australopithecines appear to have been a little knock-kneed......... Posted by: William Permalink Source February 5, 2006, 10:49 PM CT Analyze 650-Million-Year-Old Fossils
A 650-million-year-old fossil from Kazakhstan
If a future space mission to Mars brings rocks back to Earth, Schopf said the techniques he has used, called confocal laser scanning microscopy and Raman spectroscopy, could enable researchers to look at microscopic fossils inside the rocks to search for signs of life, such as organic cell walls. These techniques would not destroy the rocks. "It's astounding to see an organically preserved, microscopic fossil inside a rock and see these microscopic fossils in three dimensions," said Schopf, who is also a geologist, microbiologist and organic geochemist. "It's very difficult to get any insight about the biochemistry of organisms that lived nearly a billion years ago, and this (confocal microscopy and Raman spectroscopy) gives it to you. You see the cells in the confocal microscopy, and the Raman spectroscopy gives you the chemistry. "We can look underneath the fossil, see it from the top, from the sides, and rotate it around; we couldn't do that with any other technique, but now we can, because of confocal laser scanning microscopy. In addition, even though the fossils are exceedingly tiny, the images are sharp and crisp. So, we can see how the fossils have degraded over millions of years, and learn what are real biological features and what has been changed over time"......... Posted by: William Permalink January 4, 2006, 10:58 PM CT Ice Age clues unearthed
Using relatively new dating techniques and ancient glacial till and lake sediments gathered from the enormous, 35-foot-deep pit where the building is now rising, Wisconsin geologists have obtained the first reliable dates for the last time a massive ice sheet enveloped what are now Madison and the UW-Madison campus. "I could have taken a guess at when the ice was here last," says Dave Mickelson, emeritus professor of geology and geophysics. "But it would only have been a guess." Mickelson, however, and fellow geologist Tom Hooyer of the Wisconsin Geological and Natural History Survey, can now move beyond guesswork. Their studies of the glacial relics retrieved from the campus construction site have effectively dated the last glacial epoch of the region to about 25,000 years ago. Previously, the only reliable dates obtained from physical evidence were for areas far to the south of Madison, in Illinois where during the last ice age expansive spruce forests covered the landscape and left organic evidence that could survive the ages and be radiocarbon dated. Ice Age Dane County, says Mickelson, was tundra, little more than permafrost and grass. There were no trees to leave a record......... Posted by: William Permalink December 27, 2005, 9:42 PM CT Under the Earth that's Under the Ocean
There is a romance to exploring the soil under our feet - the remains of generations of humans before us, and prehistoric animals before them, the last artefacts of history, waiting to be found. How much more romance is there, then, in exploring the ocean. How much more romance, even, in exploring the floor of the ocean itself. Over 95% of the ocean's floor is unexplored. A number of people - maybe even you - have not even had the idea of digging in there. The Joides Resolution is a ship on a mission, one of the first of its kind. It drilled beneath the earth at the bottom of the ocean. But the ship didn't just scrape the surface. It went as far as 420 meters deep into that earth, and found the remains of organisms as old as 35 million years. And also living creatures, eating those leftovers. Dr. Bo Barker Jorgensen of the Max Planck Institute for Marine Microbiology was the German leader of the project. He sailed on the Joides Resolution and will tell you about its amazing journey of discovery......... Posted by: William Permalink December 26, 2005, 3:45 PM CT Spotlight On Dinosaurs
Dr. Phil Currie with the cranium of a Tyrannosaurus Rex
Calling his CRC in Systematics and Evolution Group the first and "long overdue pure dinosaur position" for a university in Alberta, Currie says he also looks forward to promoting dinosaur science. "Worldwide there's been very little money put into dinosaur research in the past or in the present," said Currie. "Canada is a very special place because we have some of the richest resources in the late Cretaceous anywhere in the world, and there really should be a focus on that in our museums and universities". Joining the U of A just last month, Currie has worked extensively on the discovery of feathered dinosaurs in China, meat-eating dinosaurs in Argentina, and on a pack of a dozen Albertosaurus from the badlands of central Alberta. The more than half-dozen species of feathered dinosaurs so far discovered "cover the range of meat-eating dinosaurs we have here in Alberta". Working at the Alberta Provincial Museum in the early part of 1980s, Currie helped establish the Royal Tyrrell Museum in 1985. His seven-year, $1.4 million chair will fund the continuation of his research on, among other things, the evolutionary relationship between theropod dinosaurs and their close living relatives-birds. That close relationship to birds tells us much, says Currie. Because of the theropod's similarity to birds, it is now possible, for example, to determine the sex of a theropod specimen. As the female of both the dinosaurs and birds store up calcium in their bones before laying eggs, says Currie, surplus calcium is the tell-tale sign the specimen is female......... Posted by: Jaison Permalink |
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