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

April 29, 2009, 5:16 AM CT

Match between molecular, fossil data

During a seminar at another institution several years ago, University of Chicago paleontologist David Jablonski fielded a hostile question: Why bother classifying organisms as per their physical appearance, let alone analyze their evolutionary dynamics, when molecular techniques had already invalidated that approach?

With more than a few heads in the audience nodding their agreement, Jablonski, the William Kenan Jr. Professor in Geophysical Sciences, saw more work to be done. The question launched him on a rigorous study that has culminated in a new approach to reconciling the conflict between fossil and molecular data in evolutionary studies.

For more than two decades, debate has waxed and waned between biologists and paleontologists about the reliability of their different methods. Until now, attention has focused on the dramatically different evolutionary history of certain lineages as determined by fossils or by genetics.

Researchers using molecular techniques assert that genetics more accurately determines evolutionary relationships than does a comparison of physical characteristics preserved in fossils. But how inaccurate, really, were the fossils? Jablonski and the University of Michigan's John A. Finarelli have published the first quantitative evaluation of these assumed discrepancies in the Proceedings of the National Academy of Sciences........ Posted by: William      Read more         Source

April 29, 2009, 5:13 AM CT

Discovery of early African mammal fossils

A limestone countertop, a practiced eye and Google Earth all played roles in the discovery of a trove of fossils that may shed light on the origins of African wildlife.

The circuitous and serendipitous story, featuring University of Michigan paleontologists Philip Gingerich, Gregg Gunnell and Bill Sanders, is the subject of a segment on the award-winning television series "Wild Chronicles," currently airing on public television stations (Episode 412-Looking Back; check listings for local air dates). "Wild Chronicles" is produced by National Geographic Television and presented by WLIW21 in association with WNET.ORG.

The saga began when Gingerich, an authority on ancient whales, learned of a whale fossil from Egypt that had been discovered in a most unconventional way. At a stonecutting yard in Italy where blocks of stone from around the world are sliced up for countertops, masons had noticed what looked like cross-sections of a skeleton in slabs cut from a huge hunk of limestone imported from Egypt. Paleontologist Giovanni Bianucci of the University of Pisa recognized these as fossilized remains of a whale that lived in Egypt 40 million years ago, when the region was covered by ocean.

His curiosity piqued by the discovery, Gingerich wanted to visit the site where the limestone was quarried, but the exact location was something of a mystery. Bianucci had reported that the countertop whale came from a site near the Egyptian city of Sheikh Fadl, but a colleague in Egypt told Gingerich the quarry was probably farther east-exactly where, he wasn't sure......... Posted by: William      Read more         Source

April 27, 2009, 5:13 AM CT

Did dinosaurs die from an asteroid hit?

The enduringly popular theory that the Chicxulub crater holds the clue to the demise of the dinosaurs, along with some 65 percent of all species 65 million years ago, is challenged in a paper to be reported in the Journal of the Geological Society on April 27, 2009.

The crater, discovered in 1978 in northern Yucutan and measuring about 180 kilometers (112 miles) in diameter, records a massive extra-terrestrial impact.

When spherules from the impact were found just below the Cretaceous-Tertiary (K-T) boundary, it was quickly identified as the "smoking gun" responsible for the mass extinction event that took place 65 million years ago.

It was this event which saw the demise of dinosaurs, along with countless other plant and animal species.

However, many researchers have since disagreed with this interpretation.

The newest research, led by Gerta Keller of Princeton University in New Jersey, and Thierry Adatte of the University of Lausanne, Switzerland, uses evidence from Mexico to suggest that the Chicxulub impact predates the K-T boundary by as much as 300,000 years.

"Keller and his colleagues continue to amass detailed stratigraphic information supporting new thinking about the Chicxulub impact, and the mass extinction at the end of the Cretaceous," says H. Richard Lane, program director in the National Science Foundation (NSF)'s Division of Earth Sciences, which funded the research. "The two may not be linked after all"......... Posted by: William      Read more         Source

April 16, 2009, 5:16 AM CT

Temple that sheds light on Dark Age

The discovery of a remarkably well-preserved monumental temple in Turkey - believed to be constructed during the time of King Solomon in the 10th/9th-centuries BC - sheds light on the so-called Dark Age.

Uncovered by the University of Toronto's Tayinat Archaeological Project (TAP) in the summer of 2008, the discovery casts doubt upon the traditional view that the transition from the Late Bronze Age to the Early Iron Age was violent, sudden and culturally disruptive.

Ancient sources - such as the Homeric epics and the Hebrew Bible - depict an era of widespread famine, ethnic conflict and population movement, most famously including the migrations of the Sea Peoples (or biblical Philistines) and the Israelites. This is thought to have precipitated a prolonged Dark Age marked by cultural decline and ethnic strife during the early centuries of the Iron Age. But recent discoveries - including the Tayinat excavations - have revealed that some ruling dynasties survived the collapse of the great Bronze Age powers.

"Our ongoing excavations have not only begun to uncover extensive remains from this Dark Age, but the emerging archaeological picture suggests that during this period Tayinat was the capital of a powerful kingdom, the 'Land of Palastin'," says Timothy Harrison, professor of Near Eastern Archaeology at the University of Toronto and the director of the project. "Intriguingly, the early Iron Age settlement at Tayinat shows evidence of strong cultural connections, if not the direct presence of foreign settlers, from the Aegean world, the traditional homeland of the Sea Peoples"......... Posted by: William      Read more         Source

April 6, 2009, 9:50 PM CT

Mistress of the Lionesses

The legend is that the great rulers of Canaan, the ancient land of Israel, were all men. But a recent dig by Tel Aviv University archaeologists at Tel Beth-Shemesh uncovered possible evidence of a mysterious female ruler.

Tel Aviv University archaeologists Prof. Shlomo Bunimovitz and Dr. Zvi Lederman of the Department of Archaeology and Ancient Near Eastern Civilizations have uncovered an unusual ceramic plaque of a goddess in female dress, suggesting that a mighty female "king" may have ruled the city. If true, they say, the plaque would depict the only known female ruler of the region.

The plaque itself depicts a figure dressed as royal male figures and deities once appeared in Egyptian and Canaanite art. The figure's hairstyle, though, is womanly and its bent arms are holding lotus flowers -- attributes given to women. This plaque, art historians suggest, appears to be an artistic representation of the "Mistress of the Lionesses," a female Canaanite ruler who was known to have sent distress letters to the Pharaoh in Egypt reporting unrest and destruction in her kingdom.

"We took this finding to an art historian who confirmed our hypothesis that the figure was a female," says Dr. Lederman. "Obviously something very different was happening in this city. We may have found the 'Mistress of the Lionesses' who'd been sending letters from Canaan to Egypt. The destruction we uncovered at the site last summer, along with the plaque, may just be the key to the puzzle"......... Posted by: William      Read more         Source

March 31, 2009, 5:06 AM CT

CT to reveal hidden face

Using CT imaging to study a priceless bust of Nefertiti, scientists have uncovered a delicately carved face in the limestone inner core and gained new insights into methods used to create the ancient masterpiece and information pertinent to its conservation, as per a research studyreported in the recent issue of Radiology

"We acquired a lot of information on how the bust was manufactured more than 3,300 years ago by the royal sculptor," said the study's main author Alexander Huppertz, M.D., director of the Imaging Science Institute in Berlin, Gera number of. "We learned that the sculpture has two slightly different faces, and we derived from interpretation of the CT images how to prevent damage of this extremely precious art object."

Nefertiti, the wife of the Egyptian pharaoh Akhenaten, was the most renowned Great Royal Wife of all 31 Egyptian dynasties. Considered one of the greatest finds of ancient Egypt, the bust of Nefertiti was discovered in 1912, during excavation of the studio of famous royal sculptor Thutmose.

The Nefertiti bust consists of a limestone core covered in layers of stucco of varying thickness. The bust was examined using CT for the first time in 1992, but recent advances in CT technology allowed the scientists to analyze the statue in 2007 with greater precision......... Posted by: William      Read more         Source

March 26, 2009, 9:42 PM CT

Why those fishes went extinct 65 million years ago

Large size and a fast bite spelled doom for bony fishes during the last mass extinction 65 million years ago, as per a newly released study to be published March 31, 2009, in the Proceedings of the National Academy of Sciences

Today, those same features characterize large predatory bony fishes, such as tuna and billfishes, that are currently in decline and at risk of extinction themselves, said Matt Friedman, author of the study and a graduate student in evolutionary biology at the University of Chicago.

"The same thing is happening today to ecologically similar fishes," he said. "The hardest hit species are consistently big predators".

Studies of modern fishes demonstrate that large body size is associated with large prey size and low rates of population growth, while fast-closing jaws appear to be adaptations for capturing agile, evasive preyin other words, other fishes. The fossil record provides some remarkable evidence supporting these estimates of function: fossil fishes with preserved stomach contents that record their last meals.

When an asteroid struck the earth at the end of the Cretaceous about 65 million years ago, the resultant impact clouded the earth in soot and smoke. This blocked photosynthesis on land and in the sea, undermined food chains at a rudimentary level, and led to the extinction of thousands of species of flora and fauna, including dinosaurs......... Posted by: William      Read more         Source

February 25, 2009, 5:28 AM CT

Air-filled bones helped prehistoric reptiles take first flight

In the Mesozoic Era, 70 million years before birds first conquered the skies, pterosaurs dominated the air with sparrow- to Cessna-sized wingspans. Researchers suspected that these extinct reptiles sustained flight through flapping, based on fossil evidence from the wings, but had little understanding of how pterosaurs met the energetic demands of active flight.

A new study published recently in the journal PLoS ONE by researchers from Ohio University, College of the Holy Cross and the University of Leicester explains how balloon-like air sacs, which extended from the lungs to inside the skeleton of pterosaurs, provided an efficient breathing system for the ancient beasts. The system reduced the density of the body in pterosaurs, which in turn allowed for the evolution of the largest flying vertebrates.

"We offer a reconstruction of the breathing system in pterosaurs, one that proposes the existence of a mechanism with the same essential structure to that of modern birds - except 70 million years earlier," said study co-author Leon Claessens, an assistant professor of biology at the College of the Holy Cross.

The system would have facilitated the necessary gas exchange to enable sustained activity, added co-author Patrick O'Connor, an assistant professor of biomedical sciences at the Ohio University College of Osteopathic Medicine......... Posted by: William      Read more         Source

February 12, 2009, 5:33 AM CT

What did prehistoric hominid eat?

In an unusual intersection of materials science and anthropology, scientists from the National Institute of Standards and Technology (NIST) and The George Washington University (GWU) have applied materials-science-based mathematical models to help shed light on the dietary habits of some of mankinds prehistoric relatives. Their work forms part of a newly published, multidisciplinary analysis* of the early hominid Australopithecus africanus by anthropologists at the State University of New York at Albany and elsewhere.

In the newly released study, Albany researcher David Strait and colleagues** applied finite element analysisan engineers modeling tool that employs an intricate geometric mesh to calculate the stresses and strains at play in complex shapesto the teeth and jaws of A. africanus, an African hominid that lived 2 to 3 million years ago. Their goal was to determine just how, and with how much force, the animal chomped and chewed its food. Such analyses are of great importance to anthropologists. Teeth are the hardest parts of the body, and so are the parts most likely to be found after millions of years. Careful examination of subtle features of teeth and jaws can reveal what an animal could eat, which implies what it did eat, which implies a host of things about its environment, habits and survival strategies......... Posted by: William      Read more         Source

February 4, 2009, 11:06 PM CT

Cacao Ritually Used in Chaco Canyon

Inhabitants of Chaco Canyon apparently drank chocolate from cylinders like these about a thousand years ago. That's the finding in a paper published this week by PNAS, a publication of the National Academy of Science and written by Distinguished Professor of Anthropology Patricia L. Crown and her Collaborator at the Hershey Center of Health and Nutrition W. Jeffrey Hurst.

Crown has long been fascinated by ceramic cylinders excavated at Pueblo Bonito in Chaco Canyon excavated in the Hyde Exploring Expedition from 1896-1899 and the National Geographic Society Expedition from 1920 to 1927. Only about 200 of the cylinders exist and most were found in a single room at the site. The cylinders are now housed at the Smithsonian Institution in Washington D.C. and at the American Museum of Natural History.

Archaeologists generally agree the vessels were used for some ritual, but there has been great disagreement about the specific use of the vessels. Crown was thinking about how the Maya drank chocolate from ceramic cylinders, and wondered whether the cylinders found at Chaco might have been used in the same way. It was clear that the Maya used the cylinders for chocolate. Experts could read the glyphs on the vessels that made it clear they were chocolate containers.

From 2004-2007 UNM graduate and undergraduate students had excavated the trash middens directly south of Pueblo Bonito and uncovered thousands of pottery fragments that could be used for analysis. Crown selected sherds that were from cylinders or pitchers. She could tell they were dated between 1000 and 1125 A.D. based on the decorative style. She selected a few sherds and worked with a graduate student to grind off the edges for testing, then sent the material to W. Jeffrey Hurst at the Hershey Center. He tested the powder using an analytical method he had developed and found the presence of theobromine, a marker for Theobroma cacao or chocolate......... Posted by: William      Read more         Source

February 4, 2009, 11:00 PM CT

The Advent of Earliest Known Animals

Using compounds preserved in sedimentary rocks more than 635 million years old, scientists have found some of the earliest evidence for the existence of animals.

Demosponges thrived in the shallow coastal waters of what is now Oman, as per scientist Gordon Love of the University of California at Riverside and his colleagues from MIT and other institutions.

They report the results of their research in this week's issue of the journal Nature.

"Demosponges appeared during the Neoproterozoic era, 1,000 to 542 million years ago, an era of climatic extremes and biological evolutionary developments culminating in the emergence of animals and new ecosystems," said Love.

"These sponges currently represent the oldest evidence for animals in the fossil record".

The preserved compounds Love and his colleagues discovered in these sponges, called steranes, exist in a wide variety of biochemical configurations, as per Stephen Macko, program director in the National Science Foundation (NSF)'s Division of Earth Sciences, which funded the research.

"The compounds are also known as 'biomarkers,' indicating that they can be traced directly to living organisms," said Macko.

The biomarker Love and his colleagues identified, 24-isopropylcholestane, is found in living demosponges, and now has been observed in 635 million-year-old rocks, but was not seen in older samples of the same rock formation......... Posted by: William      Read more         Source

February 4, 2009, 10:57 PM CT

Largest Prehistoric Fossil Snake

Scientists have recovered fossils from a 60-million-year-old South American snake whose length and weight might make today's anacondas seem like garter snakes.

Named Titanoboa cerrejonensis by its discoverers, the size of the snake's vertebrae suggest it weighed 1,140 kilograms (2,500 pounds) and measured 13 meters (42.7 feet) nose to tail tip.

A paper describing the find appears in this week's issue of the journal Nature.

"At its greatest width, the snake would have come up to about your hips," said geologist David Polly of Indiana University, who identified the position of the fossil vertebrae, which made an estimate possible. "The size is pretty amazing. We went a step further and asked, how warm would the Earth have to be to support a body of this size?".

Smithsonian Tropical Research Institute geologist Carlos Jaramillo and University of Florida vertebrate paleontologist Jonathan Bloch discovered the fossils in the Cerrejon Coal Mine in northern Colombia, and investigated what the snake's environment might have been like.

Paleontologist Jason Head of the University of Toronto, the Nature paper's lead author, made an estimate of Earth's temperature 58 to 60 million years ago in an area encompassed by modern-day Colombia.

"Scientists have long known of a rough correlation between a period or epoch's temperature and the size of its poikilotherms [cold-blooded creatures]," said Paul Filmer, program director in the National Science Foundation (NSF)'s Division of Earth Sciences, which co-funded the research. "As Earth's temperature increases, so does the upper size limit on poikilotherms"......... Posted by: William      Read more         Source

January 15, 2009, 7:03 PM CT

New piece in the jigsaw puzzle of human origins

In an article in today's Nature, Uppsala researcher Martin Brazeau describes the skull and jaws of a fish that lived about 410 million years ago. The study may give important clues to the origin of jawed vertebrates, and thus ultimately our own evolution.

Ptomacanthus anglicus was a very early jawed fish that lived in the Devonian period some 410 million years ago. Typically it represents a type of fossil fish known as an "acanthodian" which is characterized by a somewhat shark-like appearance and sharp spines along the leading edges of all fins (except for the tail fin). This group of early jawed fishes may reveal a great deal about the origin of jawed vertebrates (a story that ultimately includes our own origins). However, their relationships to modern jawed vertebrates (and thus their evolutionary significance) are poorly understood, owing partly to the fact that we know very little about their internal head skeleton.

"To date, we have detailed data from one genus Acanthodes, which occurred very late in acanthodian history", Martin Brazeau says.

I present details on the morphology of the braincase of Ptomacanthus, which is more than 100 million years older than Acanthodes. It is a radically different morphology from Acanthodes, which has several important implications for the relationships of acanthodians. The braincase of Acanthodes appears to most closely resemble that of early bony vertebrates, the lineage that ultimately includes humans and other land-living vertebrates). For this reason, the acanthodians were thought to share a closer ancestor with bony vertebrates than with sharks. However, the braincase of Ptomacanthus more closely resembles that of early shark-like fishes, and shares very few features in common with Acanthodes and the bony vertebrates......... Posted by: William      Read more         Source

January 8, 2009, 10:08 PM CT

First Americans arrived as 2 separate migrations

The first people to arrive in America traveled as at least two separate groups to arrive in their new home at about the same time, as per new genetic evidence published online on January 8th in Current Biology, a Cell Press publication.

After the Last Glacial Maximum some 15,000 to 17,000 years ago, one group entered North America from Beringia following the ice-free Pacific coastline, while another traversed an open land corridor between two ice sheets to arrive directly into the region east of the Rocky Mountains. (Beringia is the landmass that connected northeast Siberia to Alaska during the last ice age.) Those first Americans later gave rise to almost all modern Native American groups of North, Central, and South America, with the important exceptions of the Na-Dene and the Eskimos-Aleuts of northern North America, the scientists said.

" Recent data based on archeological evidence and environmental records suggest that humans entered the Americas from Beringia as early as 15,000 years ago, and the dispersal occurred along the deglaciated Pacific coastline," said Antonio Torroni of Universit di Pavia, Italy. "Our study now reveals a novel alternative scenario: Two almost concomitant paths of migration, both from Beringia about 15,000 to 17,000 years ago, led to the dispersal of Paleo-Indiansthe first Americans."........ Posted by: William      Read more         Source

January 6, 2009, 7:16 PM CT

Watch Out! Some Pterosaurs Take Off

Pterosaurs have long suffered an identity crisis. Pop culture heedlessly - and wrongly - lumps these extinct flying lizards in with dinosaurs. Even paleontologists assumed that because the creatures flew, they were birdlike in a number of ways, such as using only two legs to take flight.

Now comes what is thought to befirst-time evidence that launching some 500 pounds of reptilian heft into flight mandatory pterosaurs to use four limbs: two were ultra-strong wings which, when folded and balanced on a knuckle, served as front "legs" that helped the creature to walk - and leap.

Publishing in Zitteliana, Michael B. Habib, M.S., of the Center for Functional Anatomy and Evolution at the Johns Hopkins University School of Medicine, reports his comparison of bone strength in the limbs of pterosaurs to that of birds and concludes that pterosaurs had much stronger "arms" than legs. The reverse is true of birds.

"We've all seen birds take off, so that's what's most familiar," says Habib. "But with pterosaurs, extinct 65 million years and with a fossil history that goes back 250 million years, what's familiar isn't relevant".

A supersized glitch is inherent in the traditional bipedal launch model, Habib notes: "If a creature takes off like a bird, it should only be able to get as big as the biggest bird"......... Posted by: William      Read more         Source

December 18, 2008, 10:25 PM CT

Male Dinosaurs May Have Been Babysitters

Those ferocious Hollywood meat-eating dinosaurs you're used to seeing in the movies very possibly had a much softer side: the males might even have been sort of prehistoric babysitters, as per a far-flung study conducted by a Texas A&M University researcher.

Jason Moore, a post-doctoral researcher in the Department of Geology and Geophysics, and team members from Montana State University, Florida State University and the American Museum of Natural History in New York discovered that some types of male dinosaurs probably cared for and watched over eggs in much the same way that females of other species do. Their work appears in the current issue of Science magazine.

Moore and the research team examined six nests of well-preserved dinosaur eggs, with each nest containing from 22 to 30 eggs found in Montana and Mongolia. Most of the eggs were about 75 million years old.

Numerous clues - including the size of the eggs and the internal structure of the adult bones found sitting on the eggs - indicate that males, not females, likely watched over the eggs and served in a nanny-like function as the eggs slowly developed.

"The bones we found closest to the eggs don't display characteristics of female dinosaurs," Moore says of the findings.

"Modern birds descended from dinosaurs, so we can use birds as modern representatives of dinosaurs. We have looked at some other modern-day animals for similarities as well, including crocodiles, turtles, snakes and others, and asked the question in each case, 'Which of the parents were taking care of the eggs?' Comparing these modern animals to dinosaurs, the evidence all points to the males as the ones who likely cared for the eggs"......... Posted by: William      Read more         Source

December 6, 2008, 4:28 PM CT

Ancient empires declined during dry spell

The decline of the Roman and Byzantine Empires in the Eastern Mediterranean more than 1,400 years ago may have been driven by unfavorable climate changes.

Based on chemical signatures in a piece of calcite from a cave near Jerusalem, a team of American and Israeli geologists pieced together a detailed record of the area's climate from roughly 200 B.C. to 1100 A.D. Their analysis, to be reported in an upcoming issue of the journal Quaternary Research, reveals increasingly dry weather from 100 A.D. to 700 A.D. that coincided with the fall of both Roman and Byzantine rule in the region.

The researchers, led by University of Wisconsin-Madison geology graduate student Ian Orland and professor John Valley, reconstructed the high-resolution climate record based on geochemical analysis of a stalagmite from Soreq Cave, located in the Stalactite Cave Nature Reserve near Jerusalem.

"It looks sort of like tree rings in cross-section. You have a number of concentric rings and you can analyze across these rings, but instead of looking at the ring widths, we're looking at the geochemical composition of each ring," says Orland.

Using oxygen isotope signatures and impurities - such as organic matter flushed into the cave by surface rain - trapped in the layered mineral deposits, Orland determined annual rainfall levels for the years the stalagmite was growing, from approximately 200 B.C. to 1100 A.D......... Posted by: William      Read more         Source

December 1, 2008, 6:25 PM CT

Oetzi's last supper

What we eat can say a lot about us - where we live, how we live and eventually even when we lived. From the analysis of the intestinal contents of the 5,200-year-old Iceman from the Eastern Alps, Professor James Dickson from the University of Glasgow in the UK and his team have shed some light on the mummy's lifestyle and some of the events leading up to his death. By identifying six different mosses in his alimentary tract, they suggest that the Iceman may have travelled, injured himself and dressed his wounds. Their findings1 are reported in the recent issue of Springer's journal Vegetation History and Archaeobotany, which is specially dedicated to Oetzi the Iceman.

The Iceman is the first glacier mummy to have fragments of mosses in his intestine. This is surprising as mosses are neither palatable nor nutritious and there are few reports of mosses used for internal medical therapys. Rather, mosses recovered from archaeological sites tend to have been used for stuffing, wiping and wrapping.

Dickson and his colleagues studied the moss remains from the intestines of the Iceman on microscope slides, to find out more about his lifestyle and events during the last few days of his life. Their paper describes in detail the six different mosses identified and seeks to provide answers to two key questions in each case. Firstly, where did the Iceman come in contact with each species; secondly, how did each come to enter his alimentary tract......... Posted by: William      Read more         Source

November 14, 2008, 8:44 PM CT

Genetic based human diseases are an ancient evolutionary legacy

Tomislav Domazet-Loso and Diethard Tautz from the Max Planck Institute for Evolutionary Biology in Plon, Gera number of, have systematically analysed the time of emergence for a large number of genes - genes which can also initiate diseases. Their studies show for the first time that the majority of these genes were already in existence at the origin of the first cells. The search for further genes, especially those which are involved in diseases caused by several genetic causes, is thus facilitated. Furthermore, the research results confirm that the basic interconnections are to be found in the function of genes - causing the onset of diseases - can also be found in model organisms (Molecular Biology and Evolution).

The Human Genome Project that deciphered the human genetic code, uncovered thousands of genes that, if mutated, are involved in human genetic diseases. The genomes of a number of other organisms were deciphered in parallel. This now allows the evolution of these disease associated genes to be systematically studied.

Tomislav Domazet-Lošo and Diethard Tautz from the Max Planck Institute for Evolutionary Biology in Plon (Gera number of) have used for this analysis a novel statistical method, "phylostratigraphy" that was developed by Tomislav Domazet-Lošo at the Ruder Boškovic Institute in Zagreb (Croatia). The method allows the point of origin for any existing gene to be determined by tracing the last common ancestor in which this gene existed. Based on this information, it is then possible to determine the minimum age for any given gene......... Posted by: William      Read more         Source

October 14, 2008, 10:13 PM CT

Why do women get more cavities than men?

Reproduction pressures and rising fertility explain why women suffered a more rapid decline in dental health than did men as humans transitioned from hunter-and-gatherers to farmers and more sedentary pursuits, says a University of Oregon anthropologist.

The conclusion follows a comprehensive review of records of the frequencies of dental cavities in both prehistoric and living human populations from research done around the world. A driving factor was dramatic changes in female-specific hormones, reports John R. Lukacs, a professor of anthropology who specializes in dental, skeletal and nutritional issues.

His conclusions are outlined in the recent issue of Current Anthropology The study examined the frequency of dental caries (cavities) by sex to show that women typically experience poorer dental health than men. Among research evaluated were studies previously done by Lukacs. Two clinical dental studies published this year (one done in the Philippines, the other in Guatemala) and cited in the paper, Lukacs said, point to the same conclusions and "may provide the mechanism through which the biological differences are mediated".

A change in food production by agrarian societies has been linked to an increase in cavities. Anthropologists have attributed men-women differences to behavioral factors, including a sexual division of labor and dietary preferences. However, Lukacs said, clinical and epidemiological literature from varied ecological and cultural settings reveals a clear picture of the impacts on women's oral health......... Posted by: William      Read more         Source