August 18, 2009, 7:50 AM CT

Clues To Caribbean's Earliest Inhabitants

A prehistoric water-filled cave in the Dominican Republic has become a "treasure trove" with the announcement by Indiana University archaeologists of the discovery of stone tools, a small primate skull in remarkable condition, and the claws, jawbone and other bones of several species of sloths.

The discoveries extend by thousands of years the scope of investigations led Charles Beeker, director of Academic Diving and Underwater Science Programs at IU Bloomington's School of Health, Physical Education and Recreation, and his interdisciplinary team of collaborators. The researchers' focus has been on the era a mere 500 years ago when the Old World and New World first met after Christopher Columbus stepped ashore in the Caribbean -- and on scintillating pirate lore. This rare find is expected to give insights into the earliest inhabitants of the Greater Antilles and the animals they encountered.

"To be honest, I couldn't believe my eyes as I viewed each of these astonishing discoveries underwater," Beeker said. "The virtually intact extinct faunal skeletons really amazed me, but what may prove to be a fire pit from the first human occupation of the island just seems too good to be true. But now that the lithics (stone tools) are authenticated, I can't wait to direct another underwater expedition into what may prove to become one of the most important prehistoric sites in all the Caribbean."........ Posted by: William      Read more         Source

August 14, 2009, 7:14 AM CT

Evolution of human brainpower

New evidence that early modern humans used fire in southern Africa in a controlled way to increase the quality and efficiency of stone tools is changing how scientists understand the evolution of human behavior, and in particular, the evolution of human brain power.

Curtis Marean, a paleoanthropologist with the Institute of Human Origins at Arizona State University, and an international team of scientists with members from South Africa, England, Australia and France found 72,000-year-old, silcrete rocks that had been fired and flaked to make stone tools in a cave along the coast of the southern tip of Africa in Mossel Bay.

The finding indicates that humans' ability to solve complex problems may have occurred at the same time their modern genetic lineage appeared, rather than developing later as has been widely speculated......... Posted by: William      Read more         Source

August 4, 2009, 8:28 AM CT

More secrets of the mysterious Indus Valley script

Four-thousand years ago, an urban civilization lived and traded on what is now the border between Pakistan and India. During the past century, thousands of artifacts bearing hieroglyphics left by this prehistoric people have been discovered. Today, a team of Indian and American scientists are using mathematics and computer science to try to piece together information about the still-unknown script.

The team led by a University of Washington researcher has used computers to extract patterns in ancient Indus symbols. The study, published this week in the Proceedings of the National Academy of Sciences, shows distinct patterns in the symbols' placement in sequences and creates a statistical model for the unknown language.

"The statistical model provides insights into the underlying grammatical structure of the Indus script," said main author Rajesh Rao, a UW associate professor of computer science. "Such a model can be valuable for decipherment, because any meaning ascribed to a symbol must make sense in the context of other symbols that precede or follow it."

Co-authors are Nisha Yadav and Mayank Vahia of the Tata Institute of Fundamental Research and Centre for Excellence in Basic Sciences in Mumbai; Hrishikesh Joglekar of Mumbai; R. Adhikari of the Institute of Mathematical Sciences in Chennai; and Iravatham Mahadevan of the Indus Research Centre in Chennai......... Posted by: William      Read more         Source

July 28, 2009, 11:44 PM CT

Extinct rodent species discovered

An international team of researchers has discovered an extinct rodent species, based on fossil tooth remains found in Alborache, Valencia. Eomyops noeliae, from the Eomyidae family, represents the oldest find within this genus in the world.

The small number of fossils found has prevented the researchers from the University of Valencia (UV), who have led this research study, from being able to gain a full picture of this "new" rodent. However, they have been able to prove on the basis of just the teeth, the only fossil remains discovered that Eomyops noeliae was morphologically and biometrically different from other rodents of the Eomyops genus. The new species provides valuable evolutionary, biostratigraphic and paleoenvironmental information correlation to this rodent, which was of average size within the group.

"Until now, the Eomyops genus was made up of a group of small species and one large one, but no intermediately-sized kinds such as Eomyops noeliae had been found", Francisco Javier Ruiz-Snchez, main author of the study reported in the French journal Comptes Rendus Palevol and a researcher in the UV's Department of Geology, tells SINC.

The palaeontologists have also confirmed the age of the find. "The fossils found in the Morteral 20A deposit in Valencia show that this is the oldest species within the genus known in the world with absolute certainty", points out Ruiz-Snchez. As per this data, Eomyops noeliae would have lived during the Aragonese period "perhaps between the Lower and Middle Miocene (around 16 million years ago)", underscores the researcher......... Posted by: William      Read more         Source

July 21, 2009, 11:27 PM CT

Evidence from the Party that Ended 4,000 Years Ago

The party was over more than 4,000 years ago, but the remnants still remain in the gourds and squashes that served as dishware. For the first time, University of Missouri scientists have studied the residues from gourds and squash artifacts that date back to 2200 B.C. and recovered starch grains from manioc, potato, chili pepper, arrowroot and algarrobo. The starches provide clues about the foods consumed at feasts and document the earliest evidence of the consumption of algarrobo and arrowroot in Peru.

"Archaeological starch grain research allows us to gain a better understanding of how ancient humans used plants, the types of food they ate, and how that food was prepared," said Neil Duncan, doctoral student of anthropology in the MU College of Arts and Science and main author of the study that was reported in the Proceedings of the National Academy of Science (PNAS) this week. "This is the first study to analyze residue from bottle gourd or squash artifacts. Squash and bottle gourds had a variety of uses 4,000 years ago, including being used as dishes, net floats and symbolic containers. Residue analysis can help determine the specific use".

In the study, scientists recovered starch grains from squash and gourd artifacts by a method that currently is used to recover microfossils from stone tools and ceramics. First, the artifact was placed in a special water bath to loosen and remove adhering residue. Then the artifact's interior surface was lightly brushed to remove any remaining residue. The residues were collected, and starch grains were isolated from each of these sediments......... Posted by: William      Read more         Source

July 16, 2009, 11:58 PM CT

Microbial mats built 3.4-billion-year-old stromatolites

Stromatolites are dome- or column-like sedimentary rock structures that are formed in shallow water, layer by layer, over long periods of geologic time. Now, scientists from the California Institute of Technology (Caltech) and the Jet Propulsion Laboratory (JPL) have provided evidence that some of the most ancient stromatolites on our planet were built with the help of communities of equally ancient microorganisms, a finding that "adds unexpected depth to our understanding of the earliest record of life on Earth," notes JPL astrobiologist Abigail Allwood, a visitor in geology at Caltech.

Their research, published in a recent issue of the Proceedings of the National Academy of Sciences (PNAS), might also provide a new avenue for exploration in the search for signs of life on Mars.

"Stromatolites grow by accreting sediment in shallow water," says John Grotzinger, the Fletcher Jones Professor of Geology at Caltech. "They get molded into these wave forms and, over time, the waves turn into discrete columns that propagate upward, like little knobs sticking up".

Geologists have long known that the large majority of the relatively young stromatolites they studythose half a billion years old or sohave a biological origin; they're formed with the help of layers of microbes that grow in a thin film on the seafloor......... Posted by: William      Read more         Source

July 12, 2009, 9:00 AM CT

Climate Change Clues From Dinosaur Burrow

On the heels of his discovery in Montana of the first trace fossil of a dinosaur burrow, Emory University paleontologist Anthony Martin has found evidence of more dinosaur burrows - this time on the other side of the world, in Victoria, Australia. The find, to be published this month in Cretaceous Research, suggests that burrowing behaviors were shared by dinosaurs of different species, in different hemispheres, and spanned millions of years during the Cretaceous Period, when some dinosaurs lived in polar environments.

"This research helps us to better understand long-term geologic change, and how organisms may have adapted as the Earth has undergone periods of global cooling and warming," says Martin, a senior lecturer in environmental studies at Emory. Martin is also an honorary research associate at Monash University in Melbourne.

In 2006, in collaboration with colleagues from Montana State University and Japan, Martin identified the 95-million-year-old skeletal remains of a small adult dinosaur and two juveniles in a fossilized burrow in southwestern Montana. They later named the dinosaur species Oryctodromeus cubicularis, meaning "digging runner of the lair".

The scientists hypothesized that, besides caring for young in their dens, burrowing may have allowed some dinosaurs to survive extreme environments - throwing a wrench in some extinction theories......... Posted by: Tyler      Read more         Source

July 6, 2009, 6:36 PM CT

Evidence of substantial fish consumption

Freshwater fish are an important part of the diet of a number of peoples around the world, but it has been unclear when fish became an important part of the year-round diet for early humans.

A newly released study by an international team of researchers, including Erik Trinkaus, Ph.D., professor of anthropology in Arts & Sciences at Washington University in St. Louis, shows it may have happened in China as far back as 40,000 years ago.

The study will be published online the week of July 6 in the Proceedings of the National Academy of Sciences

Chemical analysis of the protein collagen, using ratios of the isotopes of nitrogen and sulfur in particular, can show whether such fish consumption was an occasional treat or a regular food item.

Analysis of a bone from one of the earliest modern human in Asia, the 40,000-year-old skeleton from Tianyuan Cave near Beijing, has shown that at least this individual was a regular fish consumer.

This analysis provides the first direct evidence for the substantial consumption of aquatic resources by early modern humans in China.

Since this occurs before there is consistent evidence for effective fishing gear, the shift to more fish in the diet likely reflects greater pressure from an expanding population at the time of modern human emergence across Eurasia......... Posted by: William      Read more         Source

June 21, 2009, 8:46 PM CT

Dino-not-so-soaring

The largest animals ever to have walked the face of the earth may not have been as big as previously thought, reveals a paper published recently in the Zoological Society of London's Journal of Zoology

Researchers have discovered that the original statistical model used to calculate dinosaur mass is flawed, suggesting dinosaurs have been oversized.

Widely cited estimates for the mass of Apatosaurus louisae, one of the largest of the dinosaurs, appears to be double that of its actual mass (38 tonnes vs. 18 tonnes).

"Paleontologists have for 25 years used a published statistical model to estimate body weight of giant dinosaurs and other extraordinarily large animals in extinct lineages. By re-examining data in the original reference sample, we show that the statistical model is seriously flawed and that the giant dinosaurs probably were only about half as heavy as is generally believed" says Gary Packard from Colorado State University.

The new predictions have implications for numerous theories about the biology of dinosaurs, ranging from their energy metabolism to their food requirements and to their modes of locomotion......... Posted by: William      Read more         Source

June 16, 2009, 5:08 AM CT

Sediment Yields Climate Record For Past Half-million Years

Scientists here have used sediment from the deep ocean bottom to reconstruct a record of ancient climate that dates back more than the last half-million years.

The record, trapped within the top 20 meters (65.6 feet) of a 400-meter (1,312-foot) sediment core drilled in 2005 in the North Atlantic Ocean by the Integrated Ocean Drilling Program, gives new information about the four glacial cycles that occurred during that period.

The new research was presented today at the Chapman Conference on Abrupt Climate Change at Ohio State University's Byrd Polar Research Center. The meeting is jointly sponsored by the American Geophysical Union and the National Science Foundation.

Harunur Rashid, a post-doctoral fellow at the Byrd Center, explained that experts have been trying to capture a longer climate record for this part of the ocean for nearly a half-century. "We've now generated a climate record from this core that has a very high temporal resolution, one that is decipherable at increments of 100 to 300 years," he said.

While climate records from ice cores can show resolutions with individual annual layers, ocean sediment cores are greatly compressed with resolutions sometimes no finer than millennia.

"What we have is unprecedented among marine records"......... Posted by: William      Read more         Source