Saturday, December 31, 2005

Marsupial Tooth Bolsters Land Bridge

The upper right molar of the 66-million year old herpetotheriid marsupial, Maastrichtidelphys meurismeti. Photo courtesy Judd Case.
From comes this article:
The recent discovery of a 66-million-year-old marsupial tooth in the Netherlands provides fresh proof that a land bridge connected the North American and European continents during the age of dinosaurs.
St. Mary's College dean of science Judd Case and his colleague James Martin say the 2-millimeter fossil, which belongs to a newly discovered, extinct species, Maastrichtidelphys meurismeti, similar to an opossum, suggests that dinosaurs and small marsupials not only lived in Europe at the same time, but also traveled the same trans-Atlantic migration route from South Dakota to the Netherlands.

Taken together with other, recent finds of North American-type duck-bill dinosaurs and certain types of snakes in Northern Europe, it appears that animals used temporary land bridges to travel across the high polar latitudes 10 million years earlier than paleontologists had thought. The tooth may be tiny, said Case, but it will have a major impact on scientists' views of Cretaceous climate, geography and life.

Earth's geography was very different back then, said Case. The Atlantic was only half as wide. Sea levels were lower -- and significantly lower at two points, around 71 and 67 million years ago. And continents were connected. Case and Martin believe animals hopped from land mass to land mass above the 70-degree latitude line.

The discovery of a North American marsupial and duck-billed dinosaurs in Maastricht indicates that the polar crossing was no chilly experiment, but a temperate migration path in a world filled with new, flowering plants.

Friday, December 30, 2005

Unified Physics Theory Explains Constraints On Evolution

Unifying constructal theory for scale effects in running, swimming and flying. 2006. Adrian Bejan and James H. Marden. Journal of Experimental Biology, vol 209: 238-248.

Gamera from HERE.

Abstract: Biologists have treated the view that fundamental differences exist between running, flying and swimming as evident, because the forms of locomotion and the animals are so different: limbs and wings vs body undulations, neutrally buoyant vs weighted bodies, etc. Here we show that all forms of locomotion can be described by a single physics theory. The theory is an invocation of the principle that flow systems evolve in such a way that they destroy minimum useful energy (exergy, food). This optimization approach delivers in surprisingly direct fashion the observed relations between speed and body mass (Mb) raised to 1/6, and between frequency (stride, flapping) and Mb-1/6 and shows why these relations hold for running, flying and swimming. Animal locomotion is an optimized two-step intermittency: an optimal balance is achieved between the vertical loss of useful energy (lifting the body weight, which later drops), and the horizontal loss caused by friction against the surrounding medium. The theory predicts additional features of animal design: the Strouhal number constant, which holds for running as well as flying and swimming, the proportionality between force output and mass in animal motors, and the fact that undulating swimming and flapping flight occur only if the body Reynolds number exceeds approximately 30. This theory, and the general body of work known as constructal theory, together now show that animal movement (running, flying, swimming) and fluid eddy movement (turbulent structure) are both forms of optimized intermittent movement.

From the Duke University press release:
A single unifying physics theory can essentially describe how animals of every ilk, from flying insects to fish, get around since all animals bear the same stamp of physics in their design.
Researchers claim that so-called "constructal theory" can explain basic characteristics of locomotion for every creature -- how fast they get from one place to another and how rapidly and forcefully they step, flap or paddle in relation to their mass. Constructal theory is a powerful analytical approach to describing movement, or flows, in nature.

The findings challenge the notion that fundamental differences between apparently unrelated forms of locomotion exist. The findings also offer an explanation for remarkable universal similarities in animal design that had long puzzled scientists, the researchers said.

"From simple physics, based only on gravity, density and mass, you can explain within an order of magnitude many features of flying, swimming and running," said James Marden, professor of biology at Penn State. "It doesn't matter whether the animal has eight legs, four legs, two, even if it swims with no legs."

The findings may have implications for understanding animal evolution, Marden said. One view of evolution holds that it is not a purely deterministic process; that history is full of chance and historical contingency. It is the idea purported by Steven Jay Gould and others that if you were to "rewind the tape" and run it again, evolution would proceed down a different path, Marden said.

Fictional avian theropod, Tatisawapudycatus jonesi, by Michael Paulus from

"Our finding that animal locomotion adheres to constructal theory tells us that -- even though you couldn't predict exactly what animals would look like if you started evolution over on earth, or it happened on another planet -- with a given gravity and density of their tissues, the same basic patterns of their design would evolve again," Marden said.

Read the rest of the story HERE.

Where Is Animal X!?

Art © William Stout.

The Society for Animal X is a group trying to right a terrible wrong. There's no animal with a [common] name that starts with "X," thereby creating a nasty void in alphabet books. So they're going to find one.

Thanks to Mark Evanier and his site for the head’s up on this.

Art © estate of Vaughn Bode. Click image to enlarge.

China First To Collect Dino Fossils?

From the People’s Daily On-Line comes this report:

China was probably the first country in the world to collect dinosaur fossils, a scientist has said.

"The Yue Kingdom in today's southeastern China had dinosaur fossils in 494 B.C.," said Sun Erhu, a research fellow with the Chengdu Institute of Biology under the Chinese Academy of Sciences.

In that year, the invading Wu Kingdom sieged Yue Kingdom's capital Kuaiji and captured a "mammoth skeleton" that had to be carried with a cart, according to "Shi Ji", or Historical Records, compiled by famous Chinese historian Sima Qian. "I bet the skeleton was actually a dinosaur fossil," Sun said after years of research. "The kingdom of Wu thought it was priceless and asked the most knowledgeable people to evaluate it."

Sun said he read about such "mammoth skeletons" in earlier historical documents, too, and guessed these were the world's earliest collections of dinosaur fossils. "Most of them were captured during wars and were collected by the kings as treasures."

Wall Street Journal, May 13, 2002 from HERE.
Read the rest of the article HERE.

Wednesday, December 28, 2005

Secrets Of Life

This comic is based on SECRETS OF LIFE, a 1956 feature-length film in WALT DISNEY'S TRUE-LIFE ADVENTURES Academy Award-winning series of nature documentaries. This 33-page adaptation of the feature-length documentary opens with a splash-page depicting an Allosaurus. Then we're shown the origins of life on primitive Earth, with prehistoric invertebrates such as trilobites, scorpions and giant cockroaches.

As land-life flourishes, we're treated to shots of dinosaurs, including an improbable battle (below) between a Tyrannosaurus rex and a sea-going Pleisosaurus. Finally, we see the development of birds (this comic was produced decades before theories about feathered dinosaurs) and mammals, such as the saber-toothed Smilodon.

A back-cover summary of the contents of WALT DISNEY'S SECRETS OF LIFE, which reads:"Thus does Nature show us that in any small part of her broad world maybe seen and explored some of her many Secrets of Life - those strange and ingenious talents for survival with which she has equipped the life she created, whether they be found on the fantastic floor of her oceans, high on her frozen mountain peaks, above her earth or under its crust…or revealed to us in a single fragile flower and one tiny Honeybee."

All the above is from the Oddball Comics site of Scott Shaw!

Tuesday, December 27, 2005

Set Sail Today: HMS Beagle

Image from HERE.

From Today In Science History:

In 1831, Charles Darwin set sail from Plymouth harbour on his voyage of scientific discovery aboard the HMS Beagle, a British Navy ship. The Captain Robert FitzRoy was sailing to the southern coast of South America in order to complete a government survey. Darwin had an unpaid position as the ship's naturalist, at age 22, just out of university.

Originally planned to be at sea for two years, the voyage lasted five years, making stops in Brazil, the Galapogos Islands, and New Zealand. From the observations he made and the specimens he collected on that voyage, Darwin developed his theory of biological evolution through natural selection, which he published 28 years after the Beagle left Plymouth.

The path of The HMS Beagle. © Pearson Education, Inc. Click to enlarge.

Dawn's Dinos

Photos © Dawn Crawford. Click to enlarge.

While I'm catching up on stuff here are some photos I should have run weeks ago!

With a lot of imagination and time, palaeoblog reader Dawn Crawford made this Velociraptor costume for her 7 year old son to wear last October 31st. It was created with commonly found items and an airbrush.

Dawn says, "He had a blast wearing it and showing it off at Halloween parties."

Thanks for sending in the photos Dawn!

New Titanosaur Found

From come this news:

Argentine paleontologists have discovered the largely intact skeleton of a young Titanosaurus that lived 71 million years ago.

"What's extraordinary about this is that the remains were articulated, as if the animal had fallen or lain down and remained that way. There were no signs that it was preyed on," local media reported geologist and paleontologist Bernardo Gonzalez Riga as saying.

Scientists discovered the remains of a foot "with all its toes and claws in an exceptional state of preservation," as well as the complete rear bones, tail, "and part of the pelvis," Gonzalez said. While the skeleton is almost complete from ribs to tale, there is no sign of the head and neck, which were likely washed away over the millennia, said Gonzalez.

Such finds are rare, said Gonzalez, adding that there are only one or two Titanosaurus in the world with complete feet. Gonzalez is a professor at Cuyo University, one of two universities with teams that excavated the remains.

An initial examination of the remains suggest a small young Titanousaurus about 10 meters long that weighed about 12 tons. The giant herbivores, which grew up to 35 meters long, lived during the late Cretaceous period (83-65 million years ago).

Monday, December 26, 2005

Dodo Graveyard Found In Mauritius

Stamp from HERE.

From comes this report:
Scientists have discovered the "beautifully preserved" bones of about 20 dodos at a dig site in Mauritius.
Little is known about the dodo, a famous flightless bird thought to have become extinct in the 17th century. No complete skeleton has ever been found in Mauritius, and the last full set of bones was destroyed in a fire at a museum in Oxford, England, in 1755.

Researchers believe the bones are at least 2,000 years old, and hope to learn more about how dodos lived. A team of Dutch and Mauritian scientists discovered the bones in a swampy area near a sugar plantation on the south-east of the island. Dutch geologist Kenneth Rijsdijk, who led the dig, said DNA samples from the dodo bones could revolutionise understanding of how the birds lived.

The dodo was mocked by Portuguese and Dutch colonialists for its size and apparent lack of fear of armed, hungry hunters. It took its name from the Portuguese word for "fool", and was hunted to extinction within 200 years of Europeans landing on Mauritius.

The Art of Matt Frank

One of the Palaeoblog's many readers is Matt Frank. Matt is an art student at the University of Texas who shows great promise, so I’m pleased to present a few of his pieces.

You can see more art at Matt’s Gallery HERE.

If anyone needs an artist, and you like what you see, contact Matt at

All art © Matt Frank

Sunday, December 25, 2005

Why Your Christmas Tree Is Not Extinct

Torus-Margo Pits Help Conifers Compete with Angiosperms. 2005. J. Pittermann, et al. Science 310: 1924.

From the University of Utah press release:

Conifers such as Christmas trees suffer a severe plumbing problem. The "pipes" (single-celled conduits called tracheids) that carry water through firs, pines and other conifers are 10 times shorter than those in flowering trees. But a University of Utah study suggests why conifers not only survive but thrive: efficient microscopic valves let water flow through conifers about as easily as it flows through other trees.

"When you are sitting around and admiring your Christmas tree, consider that it owes its existence in part to this clever microscopic valve," says John Sperry, a University of Utah biology professor who led the research team. "Without these valves, conifers could be much less common than they are, and conceivably their survival might be marginal."

Sperry says that if conifers had not evolved easy-flow valves to make up for the short length of their water pipes or conduits, "it is doubtful they could hold their own with angiosperms [flowering trees] in today's forests. It's doubtful they would dominate whole regions of North America."

In flowering trees, the pipes are multicellular conduits called vessels and are 10 times longer, or a few centimeters long (more than one inch). While scientists cannot really know if conifers might have gone extinct without their efficient type of water valve, "what this study shows is that without this valve, it would be 38 times harder for conifers to take up water, which would put them at a serious disadvantage in competition with flowering trees in temperate forests," says Sperry.

Read the rest of the press release HERE.

Saturday, December 24, 2005

Gobi Xmas Wishes

Photo © Michael Ryan

If The Simpson’s has taught us anything it’s that Buddhism does not exclude any religion (well, most of them anyways). In that spirit I present this photo of the palaeoblogger’s friend, Darren Tanke, in the Gobi desert from last summer.

That’s a prayer mound not a Christmas tree but it still makes for a ‘seasonal’ feeling picture.

Merry Christmas everyone!

Evolution In Action

“Nothing in biology makes sense except in the light of evolution”, Theodosius Dobzhansky

The Dec. 23, 2005, issue of Science has a link to a 16 minute movie entitled, “Evolution In Action”. This link should take you to a low QT version of the film, but you can watch it in different formats at the Science current issue page.

If it doesn’t work just go to the Science home page HERE and click on the “Special Video Presentation” in the “Breakthrough of the Year” box.

Read the Science article about “Evolution In Action” HERE.

500 Million Year Old Animal Family Tree Bushy

Animal Evolution and the Molecular Signature of Radiations Compressed in Time. 2005. Antonis Rokas, Dirk Krüger, Sean B. Carroll. Science 310: 1933-1938.

Abstract: The phylogenetic relationships among most metazoan phyla remain uncertain. We obtained large numbers of gene sequences from metazoans, including key understudied taxa. Despite the amount of data and breadth of taxa analyzed, relationships among most metazoan phyla remained unresolved. In contrast, the same genes robustly resolved phylogenetic relationships within a major clade of Fungi of approximately the same age as the Metazoa. The differences in resolution within the two kingdoms suggest that the early history of metazoans was a radiation compressed in time, a finding that is in agreement with paleontological inferences. Furthermore, simulation analyses as well as studies of other radiations in deep time indicate that, given adequate sequence data, the lack of resolution in phylogenetic trees is a signature of closely spaced series of cladogenetic events.

All art ©Philippe Druillet from

From the University of Wisconsin-Madison press release:

A branch-by-branch account of animal relationships over the past 500 million years is difficult to reconstruct because early animal evolution occurred in bunches. It seems that the periodic, frenetic bursts of evolution that occurred at certain times in the distant past make sorting out animal relationships -- the branches on the tree -- extraordinarily difficult.

Two decades ago, with the advent of methods to look at the family relationships of different organisms by analyzing DNA, scientists envisioned it would only be a matter of time before the various family trees for plants, animals, fungi and their kin would be resolved with genetic precision.

"[Now] it turns out that early in the origin of many types of animals, there were a lot of branching events in a short period of time," Carroll explains. Those type of episodes at key junctures in life's history -- for example, the rise of complex animals or the migration of vertebrates from the sea to land -- make the animal tree look very bushy and very murky.

The new study used a molecular approach to resolve the family tree of fungi, organisms that originated about the same time as animals. "In contrast to the animals, the tree of fungi, resolved neatly," Rokas explains. "The difficulty we are facing in telling animal relationships apart is evolution's signature that some very interesting evolutionary stuff happened here."

It is not as if evolution of new forms of animal life occurred over night, says Carroll, a UW-Madison professor of genetics. The problem is that the resolution of branches that may have taken a few million years to sprout get washed out in the much larger context of 500 million years of animal life on Earth.

"As you go into deep time, these bursts of evolutionary origins become harder to resolve," Carroll explains. In addition to the complications of deep time, animal life sometimes has a tendency to explode in radiations as organisms exploit new or newly vacant ecological niches. Famous examples of such radiations include, Darwin's finches in the Galapagos and cichlid fish in African lakes.

In that respect, the results of the new study support paleontological evidence of an explosive radiation at the dawn of animal life.

Friday, December 23, 2005

More New Dinos

A new primitive hadrosauroid dinosaur from the Early Cretaceous of Inner Mongolia (P.R. China). 2005. Pascal Godefroit, Hong Li and Chang-Yong Shang. Comptes Rendus Palevol. Vol. 4(8): 697-705.

Abstract: The right dentary of a new hadrosauroid dinosaur, Penelopognathus weishampeli, has been discovered in the Bayan Gobi Formation (Albian, Lower Cretaceous) of Inner Mongolia (P.R. China). This new taxon is characterised by its elongated, straight dental ramus, whose lateral side is pierced by about 20 irregularly distributed foramina. Its dentary teeth appear more primitive than those of Probactrosaurus, but more advanced than those of Altirhinus, both also from the Lower Cretaceous of the Gobi area. Non-hadrosaurid Hadrosauroidea were already well diversified in eastern Asia by Early Cretaceous time, suggesting an Asian origin for the hadrosauroid clade.

The ‘Giant of Ksour’, a Middle Jurassic sauropod dinosaur from Algeria. 2005. F. Mahammed et al., Comptes Rendus Palevol 4(8): 707-714.

Abstract: Continental strata of Early and Middle Jurassic age are seldom-exposed, and little is known of the history of sauropod dinosaurs prior to the neosauropod radiation of the end of the Middle Jurassic. Here, we report, in the Middle Jurassic of the Occidental Saharan Atlas (Algerian High Atlas), the discovery of a skeleton, including cranial material, of a new cetiosaurid sauropod. Chebsaurus algeriensis n. g., n. sp. represents the most complete Algerian sauropod available to date, only few remains were found before.

Images from HERE.

Thursday, December 22, 2005

Discovered This Day: First Coelacanth

Internal anatomy of the coelacanth, Latimeria chalumnae, .

From Today In Science History:

In 1938, a coelacanth, a primitive fish thought extinct, was discovered. Marjorie Courtenay-Latimer was curator of the museum in the port town of East London, northeast of Cape Town, South Africa, and always interested in seeing unusual specimens. Hendrik Goosen, captain of the trawler Nerine, called her to see his catch of the day before, made at about 70-m depth, off the Chalumna River southwest of East London. She spotted an unusual 5-ft fish in his "trash" fish pile. It was pale mauvy-blue with iridescent silver markings. She sent a sketch to Dr J.L.B. Smith, a senior lecturer in chemistry from Rhodes University in Grahamstown for identification. It was hailed as the zoological discovery of the century and equated to finding a living dinosaur!

Read this excerpt from ICHTHOS:
December 22, 1938, Captain Goosen and the Nerine put into East London harbour with the usual catch of sharks, rays, starfish and rat-tail fish. But there was one unusual fish amongst the catch that had been caught in about 70 meters, near the mouth of the Chalumna River. Once ashore Captain Goosen left word at the Museum that there were several specimens at the ship for Miss Latimer. At first she said that she was too busy because she was hard at work cleaning and articulating the fossil reptile bones collected from Tarkastad. But as it was so near Christmas time she decided to go and wish the crew a “Happy Christmas” and took a taxi to the docks. There, attracted by a blue fin amid the pile of sharks, she found a magnificent fish. She and her assistant put it in a bag and persuaded a reluctant taxi driver to take it to the museum in the boot of the car. It measured 150 cm and weighed 57.5 kg. From its hard bony scales with sharp, prickly spines and paired fins looking rather like legs, she knew that it must be some kind of primitive fish.

Image from HERE.

But her greatest problem was to preserve it until it could be identified. It was extremely hot, the fish, was too big to go into a bath and she could not find any organization willing to store it in a freezer. Although she was told by experts that it was only a type of rock cod and that she was making a fuss about nothing, she persisted in her attempts to save the fish for science. At first it was wrapped in cloths soaked in formalin but eventually, on the 26th, Mr. Center, a taxidermist, skinned it. Unfortunately the internal organs were thrown away. Marjorie went home disappointed and worried that she had not saved all the soft parts. What she had done, however, was to write immediately to her friend, JLB Smith, and send him her famous sketch of the strange fish.”

Miss Courtenay-Latimer's sketch of the first coelacanth which she posted to JLB Smith from HERE.

Learn more about Latimeria chalumnae at the Australian Museum fish web page.

The Origin Of Tetrapod Locomotion

Panderichthys from HERE.

The pelvic fin and girdle of Panderichthys and the origin of tetrapod locomotion. 2005. C. A. Boisvert. Nature 438, 1145-1147.

Abstract: One of the most marked transformations in the vertebrate transition to land was that of fins to limbs. This transformation involved not only the generation of morphological novelties (digits, sacrum) but also a shift in locomotory dominance from the pectoral to the pelvic appendage. Despite its importance, the transformation from pelvic fin to hindlimb is the least studied and least well-documented part of this transformation, which is bracketed by the osteolepiform Eusthenopteron and the early tetrapods Ichthyostega and Acanthostega, but is not directly illuminated by any intermediate form. Panderichthys is the closest tetrapod relative currently represented by complete fossils, but its pelvic fin skeleton has not been described.

Here, I present the only known articulated pelvic fin endoskeleton and associated partial pelvis of Panderichthys. The pelvic girdle is even less tetrapod-like than that of the osteolepiform Eusthenopteron, but the pelvic fin endoskeleton shares derived characteristics with basal tetrapods despite being more primitive than the pectoral fin of Panderichthys. The evolution of tetrapod locomotion appears to have passed through a stage of body-flexion propulsion, in which the pelvic fins played a relatively minor anchoring part, before the emergence of hindlimb-powered propulsion in the interval between Panderichthys and Acanthostega.

Illustration from Shubin et al.(2004) Science 304:90-93 & © Science & taken from the excellent site, (Click to enlarge)

Wednesday, December 21, 2005

Born This Day: Sewell Wright

Dec. 21, 1889 – March 3, 1988.

From the ever eloquent Today In Science History:

Wright was an American geneticist who was one of the founders of modern theoretical population genetics. He researched the effects of inbreeding and crossbreeding with guinea pigs, and later on the effects of gene action on inherited characteristics. He adopted statistical techniques to develop evolutionary theory.

Wright is best known for his concept of genetic drift, called the Sewell Wright effect - that when small populations of a species are isolated, out of pure chance the few individuals who carry certain relatively rare genes may fail to transmit them. The genes may therefore disappear and their loss may lead to the emergence of new species, although natural selection has played no part in the process.

Check out genetic drift at The Biology Project at The University of Arizona.

Learn more about Wright HERE. Image from HERE.

E (Still) = mc2

Cartoon © S. Harris

A direct test of E = mc². 2005. Rainville, J.K., et al. Nature 438: 1096-1097.

ABSTRACT: One of the most striking predictions of Einstein's special theory of relativity is also perhaps the best known formula in all of science: E=mc². If this equation were found to be even slightly incorrect, the impact would be enormous -- given the degree to which special relativity is woven into the theoretical fabric of modern physics and into everyday applications such as global positioning systems. Here we test this mass–energy relationship directly by combining very accurate measurements of atomic-mass difference, ∆m, and of γ-ray wavelengths to determine E, the nuclear binding energy, for isotopes of silicon and sulphur. Einstein's relationship is separately confirmed in two tests, which yield a combined result of 1-∆mc²/E=(-1.4±4.4)x10-7, indicating that it holds to a level of at least 0.00004%. To our knowledge, this is the most precise direct test of the famous equation yet described.

From the press release:

Albert Einstein was correct in his prediction that E=mc2, according to scientists at the Commerce Department's National Institute of Standards and Technology (NIST) and the Massachusetts Institute of Technology (MIT) who conducted the most precise direct test ever of what is perhaps the most famous formula in science.

The researchers added to a catalog of confirmations that matter and energy are related in a precise way. Specifically, energy (E) equals mass (m) times the square of the speed of light (c²), a prediction of Einstein's theory of special relativity. By comparing NIST measurements of energy emitted by silicon and sulfur atoms and MIT measurements of the mass of the same atoms, the scientists found that E differs from mc² by at most 0.0000004, or four-tenths of 1 part in 1 million. This result is "consistent with equality" and is 55 times more accurate than the previous best direct test of Einstein's formula, according to the paper.

Read the rest of the press release HERE

Tuesday, December 20, 2005

The Art of Dan McCarthy

The ever entertaining and informative Drawn! blog pointed me to the work of the incredibly talented Dan McCarthy. His site is worth checking out.
You can see more of Dan’s work at, a site I should plug more often.

FYI, is now selling a playing card deck featuring 52 great images by some of Gigposters’ best artists. Below is Dan’s card.

All art © Dan McCarthy.
It may be too late to order this for Christmas but I’m sure someone has a birthday coming up sometime in the next 365 days!

Update Note: Anyone who can help me obtain a copy of the ‘Dianogah’ poster or print should drop me a line here at the Palaeoblog. Thanks!

More Blows Against The Empire

From comes this news:

"Intelligent design" cannot be mentioned in biology classes in a Pennsylvania public school district, a federal judge said Tuesday, ruling in one of the biggest courtroom clashes on evolution since the 1925 Scopes trial.

Dover Area School Board members violated the Constitution when they ordered that its biology curriculum must include the notion that life on Earth was produced by an unidentified intelligent cause, U.S. District Judge John E. Jones III said.

Several members repeatedly lied to cover their motives even while professing religious beliefs, he said.

The school board policy, adopted in October 2004, was believed to have been the first of its kind in the nation. "The citizens of the Dover area were poorly served by the members of the Board who voted for the ID Policy," Jones wrote.

The board's attorneys had said members were seeking to improve science education by exposing students to alternatives to Charles Darwin's theory that evolution develops through natural selection. Intelligent-design proponents argue that the theory cannot fully explain the existence of complex life forms.

The plaintiffs challenging the policy argued intelligent design amounts to a secular repackaging of creationism, which the courts have already ruled cannot be taught in public schools. The judge agreed.

Read the full report HERE.

Monday, December 19, 2005

Born This Day (1944): Richard Leakey

Image from HERE.

From Today In Science History:

Leakey is a Kenyan physical anthropologist, paleontologist and second of three sons of noted anthropologists Louis Leakey and Mary Leakey. At an early age, he decided he wanted nothing to do with paleoanthropology and started a expedition business. In 1964, he led an expedition to a fossil site which sparked his interest in paleontology. Since then he has been responsible for extensive fossil finds of human ancestral forms in East Africa, including a Homo habilis skull found in 1972, and a Homo erectus skull found in 1975. His discoveries showed that man's ancestors used tools, which shows intelligence, and lived in eastern Africa at least 3 million years ago - almost doubling the previously accepted age of human origins.

Learn more about The Leakey Foundation HERE.

Woolly Mammoth DNA Sequenced

From the Penn State press release:

A team of genome researchers at Penn State University and experts in ancient DNA at McMaster University in Canada has obtained the first genomic sequences from a woolly mammoth, a mammal that roamed grassy plains of the Northern Hemisphere until it became extinct about 10,000 years ago. The team's research on bones preserved in Siberian permafrost will be published on 22 December 2005 by the journal Science on the Science Express website.

The project became possible through the discovery of exceptionally well preserved remains of a mammoth skeleton in the permafrost soil of northern Siberia, in combination with a novel high-throughput sequencing technique that could cope with the heavily fragmented DNA retrieved from the organism's mandible, its jaw bone.

"The bone material used in this study is approximately 28,000 years old, as was shown by beta carbon dating analysis," said Hendrik N. Poinar, associate professor of anthropology at McMaster University. "This was a surprising finding, as it demonstrated that the analyzed material was frozen for more than 10,000 years before the maximum of the last ice age."

A mammoth was chosen for the study, in part, because of its close evolutionary relationship to the African elephant, whose nuclear DNA sequence is publicly available. Using comparisons with elephant DNA, the researchers identified 13-million base pairs as being nuclear DNA from the mammoth, which they showed to be 98.5 percent identical to nuclear DNA from an African elephant.

A frozen mammoth skull in the ice cave displays its excellent state of preservation.
Photo © Debi Poinar, McMaster University.

The Human-Chimpanzee Split

Placing confidence limits on the molecular age of the human-chimpanzee divergence. 2005. Sudhir Kumar, et al. PNAS published December 19, 2005.

ABSTRACT: Molecular clocks have been used to date the divergence of humans and chimpanzees for nearly four decades. Nonetheless, this date and its confidence interval remain to be firmly established. In an effort to generate a genomic view of the human-chimpanzee divergence, we have analyzed 167 nuclear protein-coding genes and built a reliable confidence interval around the calculated time by applying a multifactor bootstrap-resampling approach. Bayesian and maximum likelihood analyses of neutral DNA substitutions show that the human-chimpanzee divergence is close to 20% of the ape-Old World monkey (OWM) divergence. Therefore, the generally accepted range of 23.8-35 millions of years ago for the ape-OWM divergence yields a range of 4.98-7.02 millions of years ago for human-chimpanzee divergence. Thus, the older time estimates for the human-chimpanzee divergence, from molecular and paleontological studies, are unlikely to be correct. For a given the ape-OWM divergence time, the 95% confidence interval of the human-chimpanzee divergence ranges from -12% to 19% of the estimated time. Computer simulations suggest that the 95% confidence intervals obtained by using a multifactor bootstrap- resampling approach contain the true value with >95% probability, whether deviations from the molecular clock are random or correlated among lineages. Analyses revealed that the use of amino acid sequence differences is not optimal for dating human-chimpanzee divergence and that the inclusion of additional genes is unlikely to narrow the confidence interval significantly. We conclude that tests of hypotheses about the timing of human-chimpanzee divergence demand more precise fossil-based calibrations.

From the press release at EurekAlerts!:

A team of researchers has proposed new limits on the time when the most recent common ancestor of humans and their closest ape relatives -- the chimpanzees -- lived. Scientists at Arizona State and Penn State Universities have placed the time of this split between 5 and 7 million years ago -- a sharper focus than that given by the previous collection of molecular and fossil studies, which have placed the divergence anywhere from 3 to 13 million years ago.

The scientists analyzed the largest data set yet of genes that code for proteins and also used an improved computational approach that they developed, which takes into account more of the variability -- or statistical error--in the data than any other previous study.

This time is consistent with the findings of several research groups that have used the molecular-clock method to estimate the split of humans and chimpanzees since the first attempt in 1967.

"We can conclude that humans and chimpanzees probably last shared a common ancestor between five and seven million years ago," says Blair Hedges, professor of biology at Penn State. "Although this conclusion does not exclude younger or older dates as being possible, it says they are less likely to be correct."

A big thanks to ‘Dial B For Blog’ for the images of Bobo (© DC Comics)!

Sunday, December 18, 2005

Died This Day: Sir Richard Owen (1892) & Dobzhansky (1975)

These entries from Today In Science History:

Sir Richard Owen (July 20, 1804 – Dec. 18, 1892)

English anatomist and paleontologist who is remembered for his contributions to the study of fossil animals and for his strong opposition to the views of Charles Darwin. He created the word "Dinosaur" meaning "terrible reptile" (1842). Owen synthesized French anatomical work, especially from Cuvier and Geoffroy, with German transcendental anatomy. He gave us many of the terms still used today in anatomy and evolutionary biology, including "homology". In 1856, he was appointed Superintendent of the British Museum (Natural History).

Theodosius Dobzhansky Jan. 25, 1900 – Dec. 18, 1975

Ukrainian-American geneticist and evolutionist whose work had a major influence on 20th-century thought and research on genetics and evolutionary theory. He made the first significant synthesis of Charles Darwin's theory of evolution with Gregor Mendel's theory of genetics in his book Genetics and the Origin of Species (1937). From 1918 his research gave experimental evidence that genes could vary far more than geneticists had previously believed. Thus, successful species tend to have a wide variety of genes that, while redundant in its present environment, do provide a species as a whole with genetic diversity. Such diversity enables the species to adapt effectively to changes in the surrounding environment - the basis for modern evolutionary theory.

Images from HERE & HERE.

Saturday, December 17, 2005

The Making Of Kong (1933)

From American comes THIS ARTICLE by Tom Huntington all about the people behind the 1933, 'KING KONG', and how it was made:
Even before it was made, the original King Kong was becoming a legend. “Because of the highly secret methods of filming used, the picture is being made on a closed stage and admittance is strictly forbidden,” read a notice at RKO Studio in the summer of 1932. The studio’s head of production was David O. Selznick; his assistant, Merian C. Cooper, was running Production 601. “I knew they were making something,” remembered the director George Cukor. “I would see them making it for what seemed like years and years, and we thought, dear old Coop, he’s making this preposterous picture."
Read the complete article HERE.

CMN Dinosaurs

A few pictures from the Canadian Museum of Nature's collections

CMN 8535. The red diamonds indicate types.

CMN 8893

CMN 2869