Saturday, July 22, 2006
A team of researchers from Montana State University's Museum of the Rockies have unearthed a rare skull and frill from a baby Triceratops discovered near Jordan.
Found just last week, the fossil is only the third of its kind to be discovered and is from an animal that died approximately 65 million years ago. Scientists say the find is important because it allows them to delve deeper into the lives of dinosaurs and learn about their growth.
Sonja Scarff, an MSU undergraduate student, found the specimen in Eastern Montana's Hell Creek Formation. She was part of a field crew under the direction of Jack Horner, curator of paleontology at the Museum of the Rockies.
Horner says he is thrilled about the new discovery, which he believes it is more rewarding than finding a Tyrannosaurus rex because baby Triceratops are so rare.
Prehistoric humans roamed the world's largest desert for some 5,000 years, archaeologists have revealed.
The Eastern Sahara of Egypt, Sudan, Libya and Chad was home to nomadic people who followed rains that turned the desert into grassland.
When the landscape dried up about 7,000 years ago, there was a mass exodus to the Nile and other parts of Africa.
The close link between human settlement and climate has lessons for today, researchers report in Science.
'Even modern day conflicts such as Dafur are caused by environmental degradation as it has been in the past,' Dr Stefan Kropelin of the University of Cologne, Germany, told the BBC News website.
Ten years ago, an international team of scientists reported evidence, in a controversial cover story in the journal Nature, that life on Earth began more than 3.8 billion years ago - 400 million years earlier than previously thought. A UCLA professor who was not part of that team and two of the original authors will report in late July that the evidence is stronger than ever.
Craig E. Manning, lead author of the new study and a professor of geology and geochemistry in the UCLA Department of Earth and Space Sciences, painstakingly mapped an area on Akilia Island in West Greenland where ancient rocks were discovered that may preserve carbon-isotope evidence for life at the time of their formation. Manning and his co-authors - T. Mark Harrison, a UCLA professor of geochemistry, director of UCLA's Institute of Geophysics and Planetary Physics, and University Professor at the Australian National University; and Stephen J. Mojzsis, assistant professor of geological sciences at the University of Colorado, Boulder - conducted new geologic and geochemical analysis on these rocks. Their findings will be reported in the new issue of the American Journal of Science. Harrison and Mojzsis were co-authors on the Nov. 7, 1996, study in Nature.
'This paper shows, with far greater confidence than we ever had before, that these rocks are older than 3.8 billion years,' said Manning, who has conducted extensive research in Greenland. 'We have shown that the rocks are appropriate for hosting life.'
An evolutionary arms race between early snakes and mammals triggered the development of improved vision and large brains in primates, a radical new theory suggests.
The idea, proposed by Lynne Isbell, an anthropologist at the University of California, Davis, suggests that snakes and primates share a long and intimate history, one that forced both groups to evolve new strategies as each attempted to gain the upper hand.
To avoid becoming snake food, early mammals had to develop ways to detect and avoid the reptiles before they could strike. Some animals evolved better snake sniffers, while others developed immunities to serpent venom when it evolved. Early primates developed a better eye for color, detail and movement and the ability to see in three dimensions - traits that are important for detecting threats at close range.
See the Journal of Human Evolution paper "Snakes as agents of evolutionary change in primate brains" (Abstract)
Washington DC Examiner: In their new book, "Traipsing Into Evolution: Intelligent Design and the Kitzmiller vs. Dover Decision," authors David DeWolf, John West, Casey Luskin and Jonathan Witt criticize the manner in which Judge John E. Jones III (a George W. Bush appointee) decided in Kitzmiller et al. v. Dover Area School Board (2005), the first case regarding the inclusion of "Intelligent Design" in public schools brought in a U.S. federal court. Jones ruled that the teaching of "Intelligent Design" in public school science classes violated the First Amendment due to the fact that it is not science and "cannot uncouple itself from its creationist, and thus religious, antecedents."
The Examiner interviewed the authors to get a better understanding of their arguments against Kitzmiller.
Excerpt from "Traipsing Into Evolution" [p.30]:
"Judge Jones ... repeatedly insists that ID 'requires supernatural creation.' Judge Jones can make this claim only by misrepresenting the actual views of intelligent design scientists, who consistently have maintained that empirical evidence cannot tell one whether the intelligent causes detected through modern science are inside or outside of nature. As a scientific theory, ID only claims that there is empirical evidence that key features of the universe and living things are the products of an intelligent cause. Whether the intelligent cause involved is inside or outside of nature cannot be decided by empirical evidence alone. That question involves philosophy, including metaphysics." [Interview follows]
"Traipsing Into Evolution" is currently appearing on the 'Featured Books' page of the Evolution Book Store: UK | US)
Friday, July 21, 2006
"Living fossil" discovered in South-west China: Experts recently discovered around 1200 Chinese Hynobiidae in Guiding county Southwest of China's Guizhou province. These are a type of amphibian species around 300 million years old that once used to live in the dinosaur period. The discovery has offered important reference for the study on animals' evolution and welwitschiopsida's ecological environment.
It is known from the fishery station of Guiding county that this precious species is found in several townships like Yanxia, Duliu. They live happily with Chinese giant salamanders (Andrias davidianus) in clear streams and ponds, appearing with an amazingly large population with more than 1000 found in Yanxia township alone.
DNA - the long, thin molecule that carries our hereditary material - is compressed around protein scaffolding in the cell nucleus into tiny spheres called nucleosomes. The bead-like nucleosomes are strung along the entire chromosome, which is itself folded and packaged to fit into the nucleus. What determines how, when and where a nucleosome will be positioned along the DNA sequence?
Dr. Eran Segal and research student Yair Field of the Computer Science and Applied Mathematics Department at the Weizmann Institute of Science have succeeded, together with colleagues from Northwestern University in Chicago, in cracking the genetic code that sets the rules for where on the DNA strand the nucleosomes will be situated. Their findings appeared today in Nature.
The precise location of the nucleosomes along the DNA is known to play an important role in the cell's day to day function, since access to DNA wrapped in a nucleosome is blocked for many proteins, including those responsible for some of life's most basic processes. Among these barred proteins are factors that initiate DNA replication, transcription (the transfer of genetic information from DNA to RNA) and DNA repair.
Neanderthal Genome To Be Deciphered: The Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, and 454 Life Sciences Corporation, in Branford, Connecticut, have announced an ambitious plan to complete a first draft of the Neandertal genome within the next two years.
Prof Svante Paabo, Director of the Institute's Department of Evolutionary Anthropology, and Dr. Michael Egholm, Vice-President of Molecular Biology for 454 Life Sciences will jointly direct the project, made possible by financing from the Max Planck Society. 454 Life Sciences' newly developed sequencing technology has made it possible to extract and sequence nuclear DNA from Neanderthal fossils, a hopeless task using traditional techniques.
As a trial, the collaborators have already sequenced approximately one million base pairs of nuclear Neanderthal DNA from a 38,000-year-old Croatian fossil.As a trial, the collaborators have already sequenced approximately one million base pairs of nuclear Neanderthal DNA from a 38,000-year-old Croatian fossil.
This August marks the 150th anniversary of the discovery of the first Neanderthal fossil in the Neander Valley near Dusseldorf, Germany.
Thursday, July 20, 2006
A U.S. science team says its research is adding weight to the emerging idea that RNA partly determines the inherited characteristics of plants and animals.
Vicki Chandler and colleagues at the University of Arizona studied a phenomenon called paramutation - a form of non-mendelian inheritance in which one allele of a gene can heritably dampen the expression of another. They hunted gene called mop1, which is required for paramutation at the b1 locus in maize, and found it produces an enzyme that manufactures RNA.
Once upon a time, a 2-ton wombat lumbered across the Australian Outback. Around the same time, mammoths and saber-toothed tigers had the California coastline all to themselves.
Millions of years before any of these animals existed, Tyrannosaurus rex and other colossal dinosaurs ruled the world.
These and some of the other largest and most fantastic creatures ever to walk the planet are long gone, victims of mass extinctions of large beasts. And for reasons poorly understood, often the animals to fill the voids were tiny by comparison.
...Mass extinctions occur with surprisingly regularity over the long haul. During the last 250 million years, there's been a big die-off roughly every 26 million years.
Adam Lipowski, a researcher at Adam Mickiewicz University in Poland, suggests the extinctions might sometimes be driven not by climate change or impacts from space, but by the emergence of super predators...
Wednesday, July 19, 2006
Transfer of fossils discovered in Maragheh, East Azarbaijan province, to the leading museums throughout the world has gained momentum in recent years.
According to Iran Daily English newspaper a representative of Iranian Natural History Museum said that Maragheh was once the habitat of gigantic prehistoric animals millions of years ago prior to the eruption of a volcano at Sahand Mountain.
Gholamreza Zare further said that Maragheh Fossil Area has been considered as the global hub for fossils because of the great diversity of remnants of various animal species.
'Most of the archeologists from Russia, France, Britain and the Netherlands have transferred a large number of fossils unearthed in the area to Vienna Museum for restoration,' he noted.
Zare further said that a total of 573 animal fossils have been discovered in Maragheh since 1972.
Conservatives on Ohio's Board of Education are battling to reopen the debate over the teaching of the theory of evolution in the state's public schools. Their goal is to force curriculum changes that would also allow discussion of the intelligent design theory.
The Ohio Board of Education has already reversed itself on the issue once.
Intelligent design advances the theory that certain aspects of life and the universe originate from an 'intelligent cause' and are not related to 'natural selection' or survival of the fittest. Critics of the theory include the U.S. National Academy of Sciences, which reported in 1999 that Creationism, intelligent design, and other claims of supernatural intervention in the origin of life or of species are not science because they are not testable by the methods of science.'
However, during the Ohio Board of Education's Achievement Committee meeting on July 10, conservative board member Colleen Grady proposed that the state's science standards be applied to teaching issues such as evolution, global warming and cloning.
Plant genes share the same mechanism found in mammals in the way they are marked or imprinted' to switch on or off depending on their sex, just before fertilisation. Oxford scientists have now shown that differences in the expression states of parental gene copies are not due to actual changes in the genetic code, but to chemical changes in the DNA by a naturally occurring process known as 'methylation'.
Oxford University's Department of Plant Sciences collaborated with scientists from a university in Germany and a biotech company in France (Biogemma) on the study, to be published in Nature Genetics in August.
Researchers investigated the way plant genes are marked, so that only the maternal copies are switched on while the paternal copies are switched off after fertilisation. They analysed two maize 'imprinted' genes in the products of fertilisation - the seed embryo and its accompanying placenta-like structure, the endosperm. They found that the parental copies of these genes that were switched on were not methylated, while those copies that were switched off were methylated.
Tuesday, July 18, 2006
UPDATE: Thursday, October 05, 2006 - A number of people are landing on this page from search engines apparently looking for " 'Monster' fossil find in Arctic: Pliosaur - Tyrannosaurus Rex of the Sea". Back to the original item:
Canadian fossil hunters have discovered that fierce prehistoric sea monsters apparently used the Arctic Ocean as a migration route to rule the world's oceans at roughly the same time as dinosaurs reigned on land.
The discovery is part of a fossil 'hat trick' pulled off by a six-member McGill University expedition camped on a remote and inhospitable stretch of Melville Island, 1,200 kilometres north of the Arctic Circle.
'There are lots of neat things to find here. It just takes someone to come up and look for them,' expedition leader and McGill professor Hans Larsson told the Toronto Star by satellite phone.
The expedition's big discovery is fossil remains of what looks like a new species of the sea monsters, called ichthyosaurs by scientists. No evidence of ichthyosaurs has ever been found this far north, although many ichthyosaur fossils have turned up in Asia, North American and Europe.
The rogue's gallery of human pathogens is filled with members of the Bacteria and Eukaryota domains of life. Notably absent is the third domain: Archaea. According to a recent report in the Journal of Clinical Microbiology, however, that may no longer be the case.
When Hans-Peter Horz, an assistant professor at the University Hospital in Aachen, Germany, and colleagues used real-time quantitative PCR to survey the microbial ecology of 20 infected dental root canals, they found that five contained archaeal sequences, representing up to 2.5% of the total microbial load in these samples (J Clin Microbiology, 44:1274-82, April 2006). The predominant archaeal species was Methanobrevibacter oralis.
Healthy root canals are sterile environments, Horz says. 'Microbes that are able to penetrate into this area must have some pathogenic features: They must be able to invade into the system and they must be able to evade host immune mechanisms,' he says.
Monday, July 17, 2006
Berkely, California: The molecular machinery that starts the process by which a biological cell divides into two identical daughter cells apparently worked so well early on that evolution has conserved it across the eons in all forms of life on Earth. Researchers with the U.S. Department of Energy's Lawrence Berkeley National Laboratory and the University of California at Berkeley have shown that the core machinery for initiating DNA replication is the same for all three domains of life - Archaea, Bacteria and Eukarya.
In two papers that will be concurrently published in the August edition of the journal Nature Structural and Molecular Biology (now available on-line), the researchers report the identification of a helical substructure within a superfamily of proteins, called AAA+, as the molecular "initiator" of DNA replication in a bacteria, Escherichia coli (E. coli), and in a eukaryote, Drosophila melanogaster, the fruit fly. Taken with earlier research that identified AAA+ proteins at the heart of the DNA replication initiator in archaea organisms, these new findings indicate that DNA replication is an ancient event that evolved millions of years ago, prior to when Archae, Bacteria and Eukarya split into separate domains of life.
Appropriately enough for a story about 'hobbits,' many of the details sound like something out of a fairy tale: Once upon a time, a race of little people lived on a distant island, hunting elephants and dodging dragons in a 'Lost World' wiped out by a disastrous volcanic eruption. But 'Once upon a time' is at least 12,000 years ago in this case, the pachyderms were an extinct pygmy variety and the dragons were Komodo dragons, Varanus komodoensis, the biggest lizards in the world. And the 'hobbits,' were Homo floresiensis, a remarkable human species whose remains were found on Indonesian island of Flores about three years ago.
As reported by the discovery team led by Michael Morwood of Australia's University of New England and Tony Djubiantono of the Indonesian Centre for Archaeology, the hobbits stood about three feet tall, and had surprisingly small brains for critters that seemed to have scattered tools around Liang Bua cave on Flores. Flores suffered a massive volcanic eruption around 12,000 years ago. That may have wiped the creatures out but they have become the stuff of legend, with islanders telling stories about the little people who once lived there.
First reported in the journal Nature, the vituperation among paleontologists surrounding the hobbit discovery has been almost as remarkable as the hobbits themselves.
Oslo, Norway - Living microbes found in what could be one-million-year-old ice on a remote Arctic island support the theory that the frozen planet Mars could also sustain life, researchers said on Tuesday.
An international team drilled ice core samples on the remote Svalbard islands at the extinct Sverrefjell volcano. They said that is the only place on Earth with the same minerals - called magnetite crystals - as those found on a meteorite from Mars that was discovered in the Antarctic in 1996.
'We have discovered a microbiological oasis in natural tubes of blue ice on Svalbard. This is an extremely tough environment in which we would not have expected to find life,' said team leader Hans EF Amundsen, of the University of Oslo.
Space probes sent to Mars by Nasa from the United States and by the European Space Administration (ESA) have showed evidence of water in the form of ice on the Red Planet.
Sunday, July 16, 2006
Sunday Times - Times: A geneticist says he may have solved the mystery of how 350 breeds of dog evolved from a single ancestor, the grey wolf.
Matthew Webster of the Smurfit Institute of Genetics at Trinity College, Dublin, and colleagues at Uppsala University, Sweden, say the domestication of dogs may be allowing them to override the natural laws governing evolution.
They suggest natural selection, which ensures the survival of the fittest and weeds out genetic mutations that don't provide a survival advantage, was relaxed when dogs became domesticated. Living with people allowed harmful genetic variations to flourish that would never have survived in the wild.
This interference with nature could also explain why domestic dogs developed an array of diseases such as cancer, heart disease and epilepsy.
"Dogs exhibit more variation in size, appearance and behaviour than any other mammal, but the source of this huge diversity is something of a mystery," said Webster. "Dogs were domesticated from wolves very recently, on an evolutionary timescale, so all the variability seen in different dog breeds today has been generated in a relatively short time."
Youth was easy for big predatory dinosaurs - but adulthood and old age much harder to survive, a mass graveyard of tyrannosaur fossils suggests.
This first study of dinosaur population distributions shows that most juvenile tyrannosaurs survived to reach sexual maturity, but then their death rate increased sharply in adulthood. This life-pattern is similar to those of long-lived birds and mammals.
Palaeontologists have long wondered why fossils of juvenile dinosaurs are few and far between. The answer is 'they just didn't die at those ages', says Gregory Erickson of Florida State University in Tallahassee, US, who led the new study. 'Not until they reached mid-life did they start getting knocked off.' He says the pattern echoes that of large modern herbivores like elephants and cape buffalos.
Biologists study population distributions of modern animals by counting individuals and keeping track of deaths. This is not possible for extinct creatures, and fossilised remains are also scant for many dinosaurs. But Erickson turned to the tyrannosaur family that roamed North America from about 80 to 65 million years ago, late in the Cretaceous period, which left abundant fossils.