Wednesday, May 31, 2006

Speciation Quantified: 1 Species = 1023 J

High temperatures near the equator speed up the metabolisms of the inhabitants, fueling genetic changes that actually lead to the creation of new species.
To put a number on it, it takes about 1023 - that is a 1 followed by 23 zeros - of energy units called joules to generate a new species of foraminifera plankton.

The helps explain why more living species seem to exist near the equator, a scientific observation made even before naturalist Charles Darwin set sail to South America on the H.M.S. Beagle nearly two centuries ago.

"From a scientific perspective, we can now quantify biodiversity in terms of energy," Allen said. "This will help efforts to identify and model areas for protection and conservation."

Using a mathematical model based on the body size and temperature-dependence of individual metabolism, the researchers made specific predictions on rates of speciation at the global scale. Then, using fossils and genetic data, they looked at rates of DNA evolution and speciation during a 30-million-year period in foraminifera plankton, a single-celled animal that floats in the ocean.

Researchers compared arrivals of new species of this type of plankton with differences in ocean temperatures at different latitudes ranging from the tropics to the arctic. The results agreed closely with predictions of their model.

"It takes more energy than all the fossil fuel people burn on the planet in a year to form one new species of plankton," said Dr. Andrew Allen. "In terms of conservation, this really highlights that biodiversity does have a price, and the price is very high."

The paper that this press release refers to is annoyingly not posted on the PNAS site yet, but it is probably related to this work

Cartoon © S. Harris

New Cave Species Found In Israel


Hebrew University Photo by Sasson Tiram

Discovery of eight previously unknown, ancient animal species within "a new and unique underground ecosystem" in Israel was revealed today by Hebrew University of Jerusalem researchers.
From the Hebrew University press release:

The researchers said the discovery came about when a small opening was found, leading to a cave extending to a depth of 100 meters beneath the surface of a quarry in the vicinity of Ramle, between Jerusalem and Tel Aviv. The quarry is operated by cement manufacturer Nesher Industries.

The cave, which has been dubbed the Ayalon Cave, is "unique in the world," said Prof. Amos Frumkin due to its isolation from the outside world -- the 2.5 km cave's surface is situated under a layer of chalk that is impenetrable to water.

The invertebrate animals found in the cave – four seawater and freshwater crustaceans and four terrestial species – are related to but different from other, similar life forms known to scientists. The species have been sent to biological experts in both Israel and abroad for further analysis and dating. It is estimated that these species are millions of years old. Also found in the cave were bacteria that serve as the basic food source in the ecosystem.

The animals found there were all discovered live, except for a blind species of scorpion, although Dr. Dimentman is certain that live scorpions will be discovered in further explorations and also probably an animal or animals which feed on the scorpions.

Tuesday, May 30, 2006

Mysterious Arctic Skull

A mysterious skull discovered on the edge of the Arctic Circle has sparked interest in what creatures roamed Baffin Island in the distant past, and what life a warming climate may support in the future.

From CNEWS.com:

Andrew Dialla, a resident of Pangnirtung, Nunavut, says he found the skull protruding from the frozen tundra during a walk near the shore with his daughter about a month ago.

The horned skull is about the size of a man's fist. It resembles a baby caribou skull, except at that age, a caribou wouldn't have antlers, researchers and elders have pointed out.

Its discovery has caused a stir in Canada's Eastern Arctic. Pictures of the skull, sent over e-mail, have prompted residents to speculate whether the skull might belong to a long-extinct deer or sheep that inhabited the land millions of years ago when the climate was much warmer.

Meanwhile, Dialla is considering shipping the skull south to be examined by Richard Harrington, a distinguished retired paleontologist from Ottawa's Museum of Nature. Harrington has spent over a decade helping to excavate an ancient beaver pond on Ellesmere Island in Canada's High Arctic.

That site, estimated to be four million years old, contained the remains of a now-extinct species of beaver, as well as vanished species of deer, horses, wolverines and bears.

Note: this innocuous post seems to have created a bit of a ripple on the list servers. Once we come up with a reasonable taxonomic assignment I’ll post it here.

TA DA! As we all suspected: A caribou!

New Polacanthid Found In Utah

From KLS.com:

Utah bone diggers have uncovered what could be the largest and heaviest armored dinosaur on the planet. The dino appears to be a new species and has yet to be named.

With a six foot forearm and stretching 25ft. the new Polacanthid is three times the size and weight of an armored dinosaur called Gastonia. At more than 10-thousand pounds, even a pack of Utahraptors couldn't turn this thing over. As for a new species, if it gets a name?

Dr. Reese Barrick: "Something that includes tank, or monster, or mountain, or something."

Sunday, May 28, 2006

Born This Day: Louis Agassiz

May 28, 1807 - Dec. 14, 1873

(Jean) Louis (Rodolphe) Agassiz was a Swiss-born U.S. naturalist, geologist, and teacher who made revolutionary contributions to the study of natural science with landmark work on glacier activity and extinct fishes. Agassiz began his work in Europe, having studied at the University of Munich and then as chair in natural history in Neuchatel in Switzerland. While there he published his landmark multi-volume description and classification of fossil fish.

In 1846 Agassiz came to the U.S. to lecture before Boston's Lowell Institute. Offered a professorship of Zoology and Geology at Harvard in 1848, he decided to stay, becoming a citizen in 1861. His innovative teaching methods altered the character of natural science education in the U.S. Link

More info HERE

Sea Spider Evolution With Bite

Homology of arthropod anterior appendages revealed by Hox gene expression in a sea spider. 2006. Muriel Jager et al. Nature 441: 506-508
Just when it looked like biologists had finally settled on the true placement of sea spiders on the evolutionary tree, a new study of these bizarre arthropods has come to a dramatically different conclusion. The findings may bring scientists a step closer to understanding how evolution produced today's immense diversity of invertebrates.

Link

From John Bohannon at ScienceNow:

Biologists traditionally place the sea spider within the same group as spiders and scorpions because its frontal grabbing appendages are similar to arachnids' muscular mouth appendages, called chelicerae. But whereas chelicerae grow out of the middle part of arachnid heads, sea spider grabbers seem to sprout from the front. Because the only arthropods with appendages mounted on the front of their heads are extinct species from 500 million years ago, it seemed likely that sea spiders are living fossils that have retained an extra head segment adorned with appendages.

The living fossil theory got a boost last fall with a study of sea spider development led by Amy Maxmen, a biologist at Harvard University who found that the nerves that control the larvae’s frontal grabbers are wired up to the frontmost part of the brain rather than to the middle, as they are in arachnids.

But a new study by Muriel Jager of the expression of the gene called ‘Deformed’ indicates that sea spider frontal grabbers are indeed modified versions of the chelicerae of today's spiders rather than primitive frontal appendages from days of yore. The strange positioning of the grabber nerves may be due to a rearrangement of the brain during sea spider evolution rather than an extra head segment lost in all other arthropod species.

Thursday, May 25, 2006

New Russian Mammoth Discovered

X-Men © Marvel Comices; created by Jack Kirby (who should have a truck full of money generated from new movie delivered to his estate but which is probably not getting a darn cent) & Stan Lee. Scan by me.
Fishermen in Siberia have discovered the complete skeleton of a mammoth - a find which Russian experts have described as very rare.
From the BBC News:

The remains appeared when flood waters receded in Russia's Krasnoyarsk region. The mammoth's backbone, skull, teeth and tusks all survived intact. It appears to have died aged about 50.

Alexander Kerzhayev, deputy director of the museum in the small town of Novoselovo, says it is the most significant find he can remember.

Despite the undoubted significance of this latest find, there is some bad news.

Mr Kerzhayev says his museum has neither the equipment nor the money to dig out the mammoth. At the moment, his best option may be to remove only parts of the skeleton.

Mr Kerzhayev admits it would be a pity just to leave the mammoth where it is, on the shore of a reservoir, but he says: "No one seems to care."

Wednesday, May 24, 2006

Continental Drift & The Rheic Sea

Origin of the Rheic Ocean: Rifting along a Neoproterozoic suture?. 2006. J.B. Murphy et al., Geology: Vol. 34: 325–328.
Like pieces in a giant jigsaw puzzle, continents have split, drifted and merged again many times throughout Earth’s history, but geologists haven’t understood the mechanism behind the moves. A new study now offers evidence that continents sometimes break along preexisting lines of weakness created when small chunks of land attach to a larger continent.
Throughout Earth’s history, there have been six major continental assembly and breakup events, about 500 million years apart. Currently the Earth is in breakup cycle in which the Atlantic and Indian oceans are opening.

The new study found that continents sometimes break along preexisting lines of weakness created during earlier continental collisions. Geologists had long suspected that break lines were created by the attachment of pieces onto larger land masses, but Nance and his co-authors were the first group to be able to prove this theory.

How: The scientists used geochemical “fingerprinting” to show that the small pieces of land, which today are found in the Appalachians, were originally created in an ocean. The radioactive element Samarium, which breaks down into various types of the element Neodymium, was used to determine the age of the rock (about one billion years). The amount of each element was typical of rock created in the ocean, away from larger continental masses.

Where & When:
About 650 million years ago – when the first jellyfish evolved – North America, South America and Africa were stuck together as one large continent called Gondwana, with some smaller islands floating on a neighboring continental plate. Over time, these islands collided with the large group of continents and were attached to it in a process called accretion.

About 525 million years ago, that land mass broke apart, with North America on one side and South America, Africa and the small island pieces on the other. The two plates drifted apart, forming the Iapetus Ocean.

Twenty-five million years later – at the time of the first fish and land plants – the strip of land that used to be the small islands broke off South America and Africa and began moving across Iapetus towards North America. This movement closed the Iapetus Ocean while at the same time opening the Rheic Ocean.

Tuesday, May 23, 2006

Mark Dion's Dino Room

Eric Gelber at www.artcritical.com has a long article about a installation in NYC by Mark Dion. Here’s a excerpt written in ‘Art-Critic-Speak’:
“The white cube is always present but this obscene amassing of consumer crap would leave less of an impression if everything was behind a glass display. These “dinosaurs” have little to do with real dinosaurs, and Dion emphasizes the fact that our understanding of the world is a product of capitalism. Recognizability trumps knowledge. Therefore, the solace we received throughout our childhood from imaginary forms that signify dinosaurs was preparation for a life of impossible longings and willful ignorance. Signifiers are not what they signify and the signified is always absent.”
“…Preparation for a life of impossible longings and willful ignorance”? It goes on like this for some time, most of it only making sense to other art critics.

Thanks to Mike Skrepnick for pointing this out.

Monday, May 22, 2006

How The Whale Lost His Legs

Developmental basis for hind-limb loss in dolphins and origin of the cetacean bodyplan. 2006. J. G. M. Thewissen, et al., published on-line, PNAS May 22.


Ambulocetus; reconstruction of an early close cousin of whales. © Carl Buell.
From the NSF press release:
Reseachers report that ancient whales--four-footed land animals not unlike large modern dogs--evolved into graceful, streamlined swimmers through a series of small genetic changes during the whales' embryonic development.
Thewissen and his colleagues began by exploring the embryonic development of whales' cousins, the dolphins. These creatures are intriguing because for a brief time during development they do sprout hind limbs, which quickly vanish again as the embryos reach the second month in a gestation period that lasts about 12 months.

In most mammals, explains Thewissen, "a series of genes is at work at different times, delicately interacting to form a limb with muscles, bones, and skin. In dolphins, however, at least one of the genes drops out early in the race ultimately leading to the regression of the animals' hind limbs. By analyzing dolphin embryos, Thewissen showed that the dropout is a gene called "Sonic Hedgehog," which is important at several stages of limb formation.

In whales, however, the story is more complex. Between 41 million and 50 million years ago, whales' hind limbs did shrink greatly as the former land animals began a return to the sea. But their legs showed no change in the basic arrangement and number of bones, which proved that Sonic Hedgehog was still functioning. Its loss must have come later. The dramatic loss of Sonic Hedgehog expression was not the genetic change that drove hind limb loss in whales.

Instead, Thewissen and his colleagues conclude, whales' hind limbs regressed over millions of years via "Darwinian microevolution": a step-by-step process occurring through small changes in a number of genes relatively late in development.

VISIT CARL’S EXCELLENT SITE FOR MORE ART & IDEAS

Dinos In Utah


Image Mike Miller/The Salt Lake Tribune
The Salt Lake Tribune has a nice article on vertebrate paleontology in Utah that name checks, Alan Titus, Jim Kirkland, Lindsay Zanno, and Scott Sampson.

Born This Day: Oliver Perry Hay

May 22, 1846 – Novemeber 2, 1930

Hay was an American paleontologist whose catalogs of fossil vertebrates greatly organized existing knowledge and became standard references. Hay's primary scientific interest was the study of the Pleistocene vertebrata of North America and he is renowned for his work on skull and brain anatomy. His first major work was his Bibliography and Catalogue of the Fossil Vertebrata of North America (1902), supplemented by two more volumes (1929-30). Hay also wrote on the evidence of early humans in North America. link

Harry Potter's New Dinosaur

Today paleontologist Robert Sullivan of the Pennsylvania Historical and Museum Commission will make an announcement of interest to both dinosaur lovers and Harry Potter fans.

Dr. Sullivan will announce a newly discovered dinosaur species, "Dracorex Hogwartsia", which salutes the fictional "Hogwarts School of Witchcraft and Wizardry" in the Harry Potter books.

Astute Harry Potter fans already know the derivation of "Dracorex", as its root word in Latin can be found in the Hogwarts motto, "Draco Dormiens Nunquam Titillandus", which translated into English means "Never tickle a sleeping dragon". Draco is Latin for "dragon" or "snake".

The dinosaur, a member of the pachycephalosaur family, had a flat skull with spiky horns, bumps and a long muzzle. Other pachycephalosaurs had domed foreheads. The original skull is on display at Children's Museum of Indianapolis

Three Sioux City, Iowa residents who found the 18-inch-long skull in South Dakota donated it to the museum in 2004, before it was named. "When we found the skull, all that was showing was a little of the snout and some teeth," said Steve Saulsbury, one of those who found the skull. "But as we excavated more of it, it was clear we had something unique." link

MORE INFO HERE

Sunday, May 21, 2006

Kanerva's Calgary Zoo Dinos


Calgary Zoo T. rex (left) © Kipling West; Sinclair Tyrannosaurus, Glen Rose, Texas from here.

In 2004 Kipling West did this painting for the Artists Trust Auction in Seattle. When she posted the painting on her site she accompanied it with this statement, “In 1934 John Kanerva began his life’s work, building the first of more than 50 life-sized dinosaurs at the Calgary Zoo. They were cutting edge, but soon science progressed and made the models obsolete. They were replaced with models made from the Sinclair Oil Exhibit dinosaurs (1964-65 New York World's Fair) in 1983. Today, only one of the original dinosaurs remains. "Dinny", a 'Brontosaurus', was declared an Alberta Historical Resource in 1987.” (factual info from here).

That generated an interesting series of exchanges with Kanerva's grandson.

Paraphrasing an e-mail from Kipling’s hubby,Tom Bagley: “He appears to have been upset over who got credit for designing the old Sinclair Oil logo, the New York World's Fair dinosaurs and the newer dinosaurs at the current Zoo park. Kipling had stated the Calgary dinos were replicas of the models at the 1964/65 World's Fair Dinoland exhibit. This seems to be at least partially true, as the first models few do indeed share a striking resemblance with work that came from the Louis Paul Jonas shop, which did indeed manufacture copies that have been displayed around the continent. I recall climbing on a Triceratops model as kid in Niagara Falls in 1973, that was pretty much identical to the original World's Fair one, and to one of the two Triceratops currently on display at the Zoo. The later fiberglass models at the Zoo are obviously original works, which according to Kanerva's grandson were created locally by a firm called PML Exhibits.

Apparently a book is being prepared about the old dinos, but he seems to remain adamant that the claim about the World's Fair copies is totally wrong."

Read the exchange here: HERE.

And, just for fun, a photo of Tom in this younger days with his brother at the Calgary Zoo:


Photo © TomBagley
Dino painting © Kipling West.

Science and the First Amendment

Patricia Princehouse from the Dept. of Philosophy just across the road from me at Case Western Reserve University gave a speech last week on Science and the First Amendment. Here’s an excerpt:

Science and the First Amendment
by PATRICIA J. PRINCEHOUSE

"People ask me, Why pour so much energy into protecting science education? Why not fight for literacy generally or any of a thousand other educational issues? I have two answers. One is easy: I know about evolution, so it makes sense that I would work on what I know best. The second is harder to grasp. And that is that freedom of religion is the bedrock foundation of liberty in this country. If we allow certain special-interest religious groups to co-opt the public school science classroom, to use it as a vehicle for converting children to religious views their parents don't hold, if we allow them to spout outright lies about the nature and content of science, what do we really have left? If you can lie about science and get away with it, you can lie about anything."

You can read the complete speech at tingilinde.

Thanks again to Sukie for the link to her husband’s excellent blog!

Saturday, May 20, 2006

Back From The Dead


Outer Limits card from Datajunkie.
Recent news about the discovery of species previously thought extinct can be found by clicking these links:

Living Fossil Found In New Caledonia

Colombian Frog Believed Extinct Found Alive

Fossil Footprints Found In Alaska

From IOL.co.za:

Scientists found fossilised depressions and footprints in Alaska's Denali National Park and Preserve in what is believed to be the first evidence of prehistoric wading birds probing for food, a geologist said on Friday.

The tracks and the feeding marks found in rocks formed from freshwater sediments were 65 million to 70 million years old, said Phil Brease, a geologist at Denali National Park.

Such evidence of prehistoric birds' feeding behaviour is difficult to find because the marks made in the mud disappear easily and the fossilised evidence often erodes, Brease said.

Geologists discovered the tracks and marks last summer, but confirmed the work over the winter after studying photographs and molds.

Denali National Park is an emerging hotbed of fossil findings. A team of geologists also discovered a fossilised footprint of a three-toed, meat-eating dinosaur known as a theropod.

Raptor Claw Found In Brazil

From LiveScience.com:

Ismar de Souza Carvalho said that a dinosaur claw found in Brazil likely belonged to an unknown group of dinosaurs that walked the Earth some 70 million years ago.


Photo:Renzo Gostoli
"The anatomic structure of this claw shows, quite possibly, the link between carnivore dinosaurs and birds that exist today,'' said Carvalho, a member of the Paleontological Investigation Center at Minas Gerais state university.

One expert expressed doubt that a claw fragment could prove the existence of a previously unknown dinosaur.

"This claw doesn't add particularly much to our knowledge of the origins of birds, but it does show that raptor dinosaurs were present in Brazil toward the end of the age of dinosaurs," Thomas R. Holtz, Jr., a vertebrate paleontologist at the University of Maryland, said Friday.

"The claw is similar in shape to that of many other raptors, such as velociraptors. But from there we can't infer it is likely a similar dinosaur.''

Friday, May 19, 2006

Tiktaalik the Fishopod

Here's the link to Daeschler's 'interview' on The Colbert Report; it's about halfway down the page so you'll have to search that page. It'll get replaced as the show posts new videos so watch it quick!

A big thanks to Sukie for finding this for me!

Evolution Banned in Quebec Schools

'They don't want to hear this kind of stuff'

Teachers in some northern Quebec communities say they are being told not to talk about the theory of human evolution because it offends some Inuit people. Alexandre April, a teacher in Salluit, Que., said his school principal had told teachers not to discuss the issue.

However, when students asked questions, April said Thursday he answered them as a teacher and biologist, telling them about Darwin's theory. April said that's when he got the complaint.

"A mother called, and she said that I'd told her daughter that she was a monkey. It's not the way I presented it. Not at all. So I've been told not to do it again," April said.

April said he believes his students in the tiny Inuit community on Hudson Strait have the right to learn about evolution, just like all other Canadian students.


Link

"We are able to talk about evolution of animals, but nothing about the origin of man," April said, adding the school threatened him with disciplinary action.

In at least three communities where Pentecostal Christianity has gained prominence, the opposition to teaching Darwin's theory is strong. And according to one researcher, that kind of opposition is likely to spread.

From CBC.CA - Montreal

Ted Daeschler On The Colbert Report



Last night Dr. Ted Daeschler from the Academy of Natural Sciences in Philadelphia was a 'guest' on The Colbert Report talking about Tiktaalik, or the "Fishopod" as Colbert calls it.

If anyone can send me a link to the video I'll post it here.

Here it is (for a little while)!

The Lost World



ATOMIC SURGERY has posted on the comic book adaptation of the 1960 film by Irwin Allen, "The Lost World", complete with some of the best pages from the book by Gil Kane.

No Ivory-Billed Woodpecker?


Link

From The State.com:
More than 100 volunteers and full-time researchers went through the swamps of eastern Arkansas during the winter but failed to find additional clues of the bird's existence.
"Certainly we're somewhat disappointed," said Ron Rohrbaugh of the Cornell University Lab of Ornithology in Ithaca, New York. But the lack of evidence "doesn't mean the bird's not there," Rohrbaugh said.

If new evidence about the woodpecker is discovered, state and federal agencies can reimpose restrictions on access, said Dennis Widner, manager of the wildlife management area.

A kayaker reported spotting the woodpecker on February 11, 2004 along the Cache River. Researchers later recorded videotape and audio recordings of the bird, one of six North American bird species thought to have become extinct since 1880.

Some have challenged whether the bird was actually spotted. David A. Sibley, a bird illustrator from Concord, Massachusetts, wrote earlier this year the video is not good enough to see the white stripes on the bird's back that would prove it is ivory-billed.

Homo floresiensis not a Hobbit


Photograph by John Weinstein, courtesy of the Field Museum/Science
The skull cast (left) and cast of the endocranial cavity of a modern adult human who suffered from the genetic disease microcephaly.


In a new analysis, a team of researchers report that the "hobbits" who lived on the Indonesian island of Flores some 18,000 years ago were actually a population of microcephalic modern humans, and not a new species (H. floresiensis).

Read the “Science news of the Week”article about this story HERE.

The argument against: Comment on "The Brain of LB1, Homo floresiensis".. 2006. R. D. Martin, et al. Science 3112: 999

The rebuttal by the original authors:Response to Comment on "The Brain of LB1, Homo floresiensis". 2006. Dean Falk, et al., Science 312: 999

Robert Hook Goes Home

The BBC News is reporting that the ‘lost’ manuscript by Robert Hook has finally been returned to the Royal Society.
This story was previously discussed Here and Here.

The document, which had lain hidden in a house in Hampshire, was rescued from a public auction after a fundraising effort pulled in the £940,000 needed. The "white knights" have been revealed as the Wellcome Trust, which gave £469,000, and 150 donors who came forward after the Royal Society appealed to its fellows and the general public.

The manuscript will now be rebound, transcribed and carefully analysed; and infrared scanning will be used to reveal some notes that have become illegible over time. Professor Lisa Jardine (right), a historian from Queen Mary, University of London, and biographer of Robert Hooke, was the first person to alert the Royal Society to the existence of the document. She will be working with the society to analyse the notes.

"These are the records of what happened at the Royal Society between late 1677 and late 1682. There could well be a Newton experiment in there that nobody knows about," she said.

Thursday, May 18, 2006

New Musings On The Origin of Life

From the U of Chicago press release:
A new paper argues against the widely held theory that the origin of life began with the spontaneous appearance of a large, replicating molecule such as RNA.
Instead, Shapiro raises an alternative that does not depend on a "stupendously improbable accident," presenting the more plausible idea that life began within a mixture of simple organic molecules, multiplied through catalyzed reaction cycles and an external source of available energy.

Shapiro outlines how replicator theories, though they have been supported by "prebiotic" syntheses carried out by chemists using modern apparatus and purified reagents, are highly unlikely. The creation of a molecule that can self-replicate requires the combination of diverse chemicals in a long sequence of reactions in a specific order, interspersed by complicated separations, purifications, and changes in locale.

Instead, Shapiro introduces the idea of a "driver" reaction, linked to a free energy source, that helps convert an unorganized mixture into a organized, self-regulated metabolic network.

"If we wish a more plausible origin of life, then we must work with the assumption that life began, somehow, among one of the mixtures of simple organic molecules that are produced by abiotic processes," writes Shapiro. "Nature will be instructing us, rather than we attempting to impose our schemes onto it."

"Small Molecule Interactions Were Central to the Origin of Life." Robert Shapiro, The Quarterly Review of Biology, June 2006.

Human & Chimps May Have Interbred

Genetic evidence for complex speciation of humans and chimpanzees. 2006. N. Patterson, et al., Nature, published on-line May 17.

From News@nature.com:
The evolutionary split between humans and our nearest evolutionary cousins, chimpanzees, may have occurred more recently than we thought — leading to the controversial theory that our two sets of ancestors may have interbred many thousands of years after first parting company.
The discovery also casts doubt on the status of fossils that were thought to represent the first flowering of the human branch of the evolutionary tree — but which now may have to be reclassified as coming from a time before our split with the rest of the apes.

Previous estimates put the split at as much as 7 million years ago — meaning that Toumaï, a fossil dating from at least 6.5 million years ago in Chad and assigned to the species Sahelanthropus tchadensis, was hailed as the earliest-known member of the line that gave rise to modern humans.

But researchers now calculate that the split may have occurred no more than 6.3 million years ago, and possibly as recently as 5.4 million. That would make Toumaï older than the time of the split.

The researchers make their claim after comparing the genetic codes of humans, chimpanzees, gorillas and other primates in unprecedented detail — more than 20 million DNA 'letters' in all. By checking the differences between different species' DNA sequences, they were able to estimate the time since they first diverged.

Wednesday, May 17, 2006

Missing Link In Flowering Plant Evolution Found

Embryological evidence for developmental lability during early angiosperm evolution. 2006. ‘Ned’ Friedman, Nature 441: 337-340.


Link

From the U of Colorado at Boulder press release:
A new University of Colorado at Boulder study involving a "living fossil plant" that has survived on Earth for 130 million years suggests its novel reproductive structure may be a "missing link" between flowering plants and their ancestors.
The Amborella plant, found in the rain forests of New Caledonia in the South Pacific, has a unique way of forming eggs that may represent a critical link between the remarkably diverse flowering plants, known as angiosperms, and their yet to be identified extinct ancestors, said "Ned" Friedman. Angiosperms are thought to have diverged from gymnosperms -- the dominant land plants when dinosaurs reigned in the Cretaceous and Jurassic periods -- roughly 130 million years ago and have become the dominant plants on Earth today.

"The study shows that the structure that houses the egg in Amborella is different from every other flowering plant known, and may be the potential missing link between flowering plants and their progenitors."

In basic terms, Amborella has one extra sterile cell that accompanies the egg cell in the female part of its reproductive apparatus known as the embryo sac, according to the study. The discovery of the unique configuration of the egg apparatus, which is thought to be a relic of intense evolutionary activity in early angiosperm history, "is akin to finding a fossil amphibian with an extra leg."

Read the rest HERE.

This Day In History: Scopes Monkey Law Repealed

Read about it HERE.


Link.

Ryan North of Dinosaur Comics


Link
Can you still call yourself a webcartoonist if you don't actually draw your own strip?
Toronto resident Ryan North proves that the answer is a resounding "yes". Three years ago, he launched Dinosaur Comics, the conversational adventures of T-Rex and his friends Dromeceiomimus and Utahraptor, where characters a are rendered in archaic clip art and the panel structure never changes. Dinosaur Comics' popularity has been increasing ever since: Ryan's site averages 70,000 hits per day and he supports himself financially through t-shirt and book sales. The former computer science student now spends his days answering fan-mail, working on several internet-related side projects, and talking to Torontoist over soup and sandwiches.

Read the interview with North in The Torontoist HERE.

Finding A Chimp’s Genetic Hotspot

Hotspots for copy number variation in chimpanzees and humans. 2006. G. H. Perry, et al. PNAS published on-line 2006


Link
From the Arizona State University press release:
Researchers have found genetic ‘hotspots’ in chimpanzees suggesting implications for the understanding of genomic evolution in all species.

Hotspots are dynamic regions of the human genome that are potentially involved in the rapid evolution of morphological and behavioral characteristics that are genetically determined.

"We found that chimpanzees have many copy number variants -- duplications or deletions of large segments of DNA -- in the same regions of the genome as do humans. What this suggests is that some regions of the genomes are inherently unstable in both humans and chimpanzees," said Perry who is the study's lead author.

"This is a relatively new area of research and this is the first time this has been investigated on a genome-wide scale in a population sample of nonhuman primates,"

"These copy number variants may be very significant from an evolutionary perspective, and they're important to study and understand. We talk about genetic diseases and cures, but first you have to find out that genetic differences such as copy number variants are there. And then you can study what they're involved in and what they mean from a morphological variation and disease standpoint."

"Ultimately, we can use information about within-a-species variation to identify unusual patterns between species," he says. "This may highlight copy number differences between humans and chimpanzees that were somehow involved in the evolution of human-specific traits."

Tuesday, May 16, 2006

RMDRC Marine Reptiles

As promised yesterday, here are some marine reptiles I photographed at the Rocky Mountain Dinosaur Resource Center in Colorado.


Photo © M. Ryan


Photo © M. Ryan


Photo © M. Ryan


Photo © M. Ryan

First Nuclear Neanderthal DNA Sequenced

Neanderthal DNA yields to genome foray

From Rex Dalton at news@nature.com:

The first nuclear DNA sequences from a Neanderthal (Homo neanderthalensis) have been reported. The results should provide clues about when certain diseases, or traits such as hair or skin colour, arose. They also have geneticists excited about the idea of sequencing a Neanderthal genome.

Svante Pääbo, a palaeogeneticist, and his team have probed 60 Neanderthal specimens from museums for hints that the DNA might have survived millennia of degradation. The species lived across Europe and western Asia from 300,000 to around 30,000 years ago, with the first specimen found in 1856 near Dusseldorf, Germany.

On May 12th Pääbo's team reported at the Biology of Genomes meeting at New York's Cold Spring Harbor Laboratory that they had managed to sequence around a million base pairs of nuclear DNA — around 0.03% of the genome . This from is a 45,000-year-old male specimen found in Vindija Cave outside Zagreb, Croatia.

One finding so far is that the Neanderthal Y chromosome is substantially more different from human and chimp Y chromosomes than are other chromosomes. This suggests that little interbreeding occurred, at least among the more recent Neanderthal species.

James Noonan, a postdoc in Rubin's lab, reported at the Cold Spring Harbor meeting that preliminary analysis of the 75,000 base pairs sequenced so far shows that Neanderthals diverged from the lineage that led to modern humans about 315,000 years ago - around the time that had been thought. Homo sapiens is known to have evolved at least 200,000 years ago.

Nebraska's Ashfall Fossil Beds Designated National Natural Landmark


Photograph © Annie Griffiths Belt/Corbis
The U.S. Department of Interior has designated Nebraska's Ashfall Fossil Beds as a national natural landmark, the first such landmark to be designated in almost two decades.
From Stefan Lovgren at National Geographic News:

The site, near the town of Neligh is home to hundreds of skeletons of extinct rhinos, camels, three-toed horses, and other vertebrates that were killed and buried by ash from a huge volcanic eruption some 12 million years ago. It is the only place on Earth where large numbers of fossil mammals have been found as whole, three-dimensionally preserved skeletons.

The Ashfall Fossil Beds were uncovered in the early 1970s by Dr. Mike Voorhies, the current curator of paleontology at the University of Nebraska State Museum in Lincoln. In 1971 he found a skull of a rhino calf protruding from an eroding ravine. The skull turned out to be part of a complete skeleton embedded in volcanic ash.

About 12 million years ago, a volcano in modern-day Idaho spread a blanket of ash over large parts of what is now the midwestern United States. A layer of this powdered glass one or two feet (one- to two-thirds of a meter) thick covered the grasslands of northeastern Nebraska. Most of the animals living in the area survived the actual ashfall, but as they continued to graze on the ash-covered grasses, their lungs began to fill with the deadly particles.

Monday, May 15, 2006

Born This Day: Clarence Edward Dutton

May 15, 1841 - died Jan. 4, 1912.

Dutton was an American geologist who in 1887 was put in charge of the division of volcanic geology and seismology. His investigation of the Charleston earthquake of 1886, published in the reports of that survey, attracted wide attention and helped to develop scientific interest in the study of earthquake phenomena. He is acknowedged as being the pioneer seismologist who developed and named the principle of isostasy.

Info from Wikipedia

Rocky Mountain Dinos



Over the weekend I was the guest of the Rocky Mountain Dinosaur Resouce Center in Woodland Park, CO, just outside of Colorado Springs, where I gave a lecture on T. rex. I'm posting a few of the pictures I took while I was there:


'Stan' the T. rex. Photo © M. Ryan


Xiphactinus model and skeleton. Photo © M. Ryan


Photo © M. Ryan


Photo © M. Ryan

Mike Triebold (far right), wife J.J. (left), and Tracie Bennitt were gracious hosts. I'd recommend that anyone in the area stop in to see their excellent displays.

Tomorrow: RMDRC marine reptiles.

Sunday, May 14, 2006

Methane-Belching Bugs Burped Up Life

The Stepwise Evolution of Early Life Driven by Energy Conservation. 2006. J. Ferry and C. H. House. Molecular Biology and Evolution 23: 1286-1292.
Two laboratories at Penn State set out to show how an obscure undersea microbe metabolizes carbon monoxide into methane and vinegar. What they found has become the inspiration for a fundamental new theory of the origin of life on Earth, reconciling a long-contentious pair of prevailing theories.
The apparently irreconcilable "heterotrophic" and "chemoautotrophic" theories of the origin of life both focus on the processes by which chemical building blocks first appeared for primitive life to assemble into complex molecules.

According to the heterotrophic theory, a primordial soup of simple molecules arose first, driven by nonbiological energy sources like lightning, and led eventually to primitive life forms. One difficulty with this theory is due to the huge variety and complexity of organic molecules that would have had to arise spontaneously.


Poster from HERE.

In contrast, the chemoautotrophic theory rests on the idea that primitive life forms themselves, perhaps associated with catalytic iron and sulfur minerals, gave rise to the first simple biological molecules. The obstacles to this theory are the large number of steps in the biochemical cycles that have been suggested, and the staggering structural complexity of the only known enzyme complexes that drive those reactions.

This longstanding debate between the heterotrophic and chemotrophic theories," House continues, "revolved around carbon fixation." The new thermodynamic theory inverts the focus, Ferry says. "All these pathways evolved first to make energy. Afterwards, they evolved to fix carbon. These ideas suggest a totally new perspective. It's truly a quantum leap--a milestone."

Early Penguins & The Evolution of Birds

Early Penguin Fossils, Plus Mitochondrial Genomes, Calibrate Avian Evolution. 2006. Kerryn E. Slack, et al. Molecular Biology and Evolution 2006 23(6):1144-1155.


Image from the paper. Click to enlarge

Abstract: Testing models of macroevolution, and especially the sufficiency of microevolutionary processes, requires good collaboration between molecular biologists and paleontologists. We report such a test for events around the Late Cretaceous by describing the earliest penguin fossils, analyzing complete mitochondrial genomes from an albatross, a petrel, and a loon, and describe the gradual decline of pterosaurs at the same time modern birds radiate.

The penguin fossils comprise four naturally associated skeletons from the New Zealand Waipara Greensand, a Paleocene (early Tertiary) formation just above a well-known Cretaceous/Tertiary boundary site. The fossils, in a new genus (Waimanu), provide a lower estimate of 61–62 Ma for the divergence between penguins and other birds and thus establish a reliable calibration point for avian evolution. Combining fossil calibration points, DNA sequences, maximum likelihood, and Bayesian analysis, the penguin calibrations imply a radiation of modern (crown group) birds in the Late Cretaceous. This includes a conservative estimate that modern sea and shorebird lineages diverged at least by the Late Cretaceous about 74 ± 3 Ma (Campanian).

It is clear that modern birds from at least the latest Cretaceous lived at the same time as archaic birds including Hesperornis, Ichthyornis, and the diverse Enantiornithiformes.

Pterosaurs, which also coexisted with early crown birds, show notable changes through the Late Cretaceous. There was a decrease in taxonomic diversity, and small- to medium-sized species disappeared well before the end of the Cretaceous. A simple reading of the fossil record might suggest competitive interactions with birds, but much more needs to be understood about pterosaur life histories.

Additional fossils and molecular data are still required to help understand the role of biotic interactions in the evolution of Late Cretaceous birds and thus to test that the mechanisms of microevolution are sufficient to explain macroevolution.

Note: This is an open access article that can be downloaded HERE

Thursday, May 11, 2006

Lebanon's 1st Dinosaur

First nonavian dinosaur from Lebanon: a brachiosaurid sauropod from the Lower Cretaceous of the Jezzine District. 2006. E. Buffetaut, et al. Naturwissenschaften. Published On-line.

Abstract: Two sauropod teeth from an Early Cretaceous (Neocomian) fluviodeltaic sandstone near Jezzine (Southern Lebanon) are the first nonavian dinosaur remains to be reported from Lebanon. Their distinctive character places them within Brachiosauridae. The sauropod teeth from Lebanon are a significant addition to the very scanty dinosaur record from the Levant, which hitherto consisted mainly of very poorly preserved and not easily identifiable specimens. The Basal Cretaceous Sandstone of Lebanon, thus, appears to be a potentially important source of fossil vertebrate material.

From Yahoo News:

Fossil-hunters have uncovered the first dinosaur remains in Lebanon, adding precious evidence to the theory that millions of years ago, the Middle East was covered with lush forests where giant reptiles roamed.

Eric Buffetaut (left) of France's National Centre for Scientific Research (CNRS) and Dany Azar of the Lebanese University describe two teeth of an animal related to Brachiosaurus.

A complete tooth was found near the southern city of Jezzine last year and another, incomplete, was discovered there in 1969.

Photo from HERE

New Marine Archosaur Described

An unusual archosaurian from the marine Triassic of China. 2006. Chun Li, et al. Naturwissenschaften 93: 200-206.

Abstract: A new Triassic archosaurian from China shows a number of aquatic specializations, of which the most striking is the extreme lateral compression of the long tail. Others that may also reflect aquatic adaptations include platelike scapula and coracoid, elongate neck with extremely long and slender ribs, and reduction of osteoderms.

In contrast, its pelvic girdle and hind limb have no aquatic modifications. Anatomic features, taphonomy, and local geological data suggest that it may have lived in a coastal–island environment. This lifestyle, convergent with some Jurassic marine crocodyliforms that lived at least 40 million years later and the saltwater species of extant Crocodylus, contradicts with the prevailing view that Triassic archosaurians were restricted to nonmarine ecosystems.

Its mosaic anatomy represents a previously unknown ecomorph within primitive archosaurians.

Neolithic Britons Brutal Beaters

A survey of British skulls from the early part of the New Stone Age, or Neolithic, shows societies then were more violent than was supposed.
From BBC News:

Early Neolithic Britons had a one in 20 chance of suffering a skull fracture at the hands of someone else and a one in 50 chance of dying from their injuries. Blunt instruments such as clubs were responsible for most of the trauma.

Rick Schulting of Queen's University Belfast and Michael Wysocki from the University of Central Lancashire looked at skulls spanning the period from 4000 BC to 3200 BC.

"We generally think of Neolithic people as living peaceful lives - they were busy looking after cereal crops and rearing livestock," Mr Wysocki told the BBC News website.

This is not the first time human-induced injuries have been identified in Neolithic people. But the authors say it is the first study to give some idea of the overall frequency of such trauma.

"But it was a much more violent society."

Details were presented at a meeting of the Society for American Archaeology and reported in New Scientist magazine. The research originally appeared in the Proceedings of the Prehistoric Society journal.
Skull Photo © Rick Schulting

Wednesday, May 10, 2006

Congratulations to Drs. Snively & Jamniczky!


Photo © M. Ryan

Congratulations to Dr. Eric Snively (above), who defended his Ph.D. dissertation, “Neck Musculoskeletal Function in the Tyrannosauridae (Theropoda, Coelurosauria): Implications for Feeding Dynamics”, yesterday.

Also, belated congrats as well to Dr. Heather Jamniczky who also recently defended her Ph. D. dissertation, “Turtle Cranial Arterial Circulation: Integrative Analysis of a Systematically Influential Character Complex.”

Both Heather and Eric are friends from my old lab at the University of Calgary, and studied with my advisor, Dr. Tony Russell.

Creationism Dismissed As 'Paganism' By Vatican's Astronomer

BELIEVING that God created the universe in six days is a form of superstitious paganism, the Vatican astronomer Guy Consolmagno claimed [May 5th].
From Ian Johnston at the New Scotsman.com:

Brother Consolmagno, who works in a Vatican observatory in Arizona and as curator of the Vatican meteorite collection in Italy, said a "destructive myth" had developed in modern society that religion and science were competing ideologies.



He described creationism, whose supporters want it taught in schools alongside evolution, as a "kind of paganism" because it harked back to the days of "nature gods" who were responsible for natural events.

Brother Consolmagno argued that the Christian God was a supernatural one, a belief that had led the clergy in the past to become involved in science to seek natural reasons for phenomena such as thunder and lightning, which had been previously attributed to vengeful gods. "Knowledge is dangerous, but so is ignorance. That's why science and religion need to talk to each other," he said.

"Religion needs science to keep it away from superstition and keep it close to reality, to protect it from creationism, which at the end of the day is a kind of paganism - it's turning God into a nature god. And science needs religion in order to have a conscience, to know that, just because something is possible, it may not be a good thing to do."

Read the rest of the article HERE. Thanks to Sukie for this story!

The World of Anthro


Anthro © DC Comics. Info from HERE. Image from HERE.

Allegedly the first Cro-Magnon boy, Anthro was born into a society so much more primitive and savage than himself, circa 40.000 years ago. Anthro's father was Ne-Ahn, Chief of the Bear Tribe, which lived a nomadic existence trying to survive the hostile elements in an ever-changing world. Anthro had a keen intellect and a sense of innovation that few of his fellow cavemen knew. Thus, he experienced many adventures during his lifetime, sometimes with his girlfriend Embra or his brother Lart. More images HERE.

Monday, May 08, 2006

Dave Weishampel Interview

The Johns Hopkins Newsletter as a short interview with Dr. Dave Weishampel conducted by Sam Engel. Here’s an excerpt:

"I'm not one of those gifted namers of dinosaurs. Most recently I named something called Zalmoxes. It's a fat, yet reasonably small, herbivorous dinosaur, also an ornithopod, and it comes from Transylvania. Zalmoxes was a major deity of the Dacian people, who are thought to be the original inhabitants of Transylvania. Zalmoxes advocated things like vegetarianism, and my guys a plant-eater, and he was supposed to be the god of the underworld, and we had to dig him up. It's a lovely guy. It was a real thrill. Transylvanian dinosaurs come out in dribs and drabs out of the rock and so it was really nice to be able to create the animal from isolated parts."