Captain, there be trolls here!
Posted on 04/05/2006 10:32:31 AM PDT by PatrickHenry
Paleontologists have discovered fossils of a species that provides the missing evolutionary link between fish and the first animals that walked out of water onto land about 375 million years ago. The newly found species, Tiktaalik roseae, has a skull, a neck, ribs and parts of the limbs that are similar to four-legged animals known as tetrapods, as well as fish-like features such as a primitive jaw, fins and scales.
These fossils, found on Ellesmere Island in Arctic Canada, are the most compelling examples yet of an animal that was at the cusp of the fish-tetrapod transition. The new find is described in two related research articles highlighted on the cover of the April 6, 2006, issue of Nature.
"Tiktaalik blurs the boundary between fish and land-living animal both in terms of its anatomy and its way of life," said Neil Shubin, professor and chairman of organismal biology at the University of Chicago and co-leader of the project.
Tiktaalik was a predator with sharp teeth, a crocodile-like head and a flattened body. The well-preserved skeletal material from several specimens, ranging from 4 to 9 feet long, enabled the researchers to study the mosaic pattern of evolutionary change in different parts of the skeleton as fish evolved into land animals.
The high quality of the fossils also allowed the team to examine the joint surfaces on many of the fin bones, concluding that the shoulder, elbow and wrist joints were capable of supporting the body-like limbed animals.
"Human comprehension of the history of life on Earth is taking a major leap forward," said H. Richard Lane, director of sedimentary geology and paleobiology at the National Science Foundation. "These exciting discoveries are providing fossil 'Rosetta Stones' for a deeper understanding of this evolutionary milestone--fish to land-roaming tetrapods."
One of the most important aspects of this discovery is the illumination of the fin-to-limb transition. In a second paper in the journal, the scientists describe in depth how the pectoral fin of the fish serves as the origin of the tetrapod limb.
Embedded in the fin of Tiktaalik are bones that compare to the upper arm, forearm and primitive parts of the hand of land-living animals.
"Most of the major joints of the fin are functional in this fish," Shubin said. "The shoulder, elbow and even parts of the wrist are already there and working in ways similar to the earliest land-living animals."
At the time that Tiktaalik lived, what is now the Canadian Arctic region was part of a landmass that straddled the equator. It had a subtropical climate, much like the Amazon basin today. The species lived in the small streams of this delta system. According to Shubin, the ecological setting in which these animals evolved provided an environment conducive to the transition to life on land.
"We knew that the rocks on Ellesmere Island offered a glimpse into the right time period and the right ancient environments to provide the potential for finding fossils documenting this important evolutionary transition," said Ted Daeschler of the Academy of Natural Sciences in Philadelphia, a co-leader of the project. "Finding the fossils within this remote, rugged terrain, however, required a lot of time and effort."
The nature of the deposits where the fossils were found and the skeletal structure of Tiktaalik suggests the animal lived in shallow water and perhaps even out of the water for short periods.
"The skeleton of Tiktaalik indicates that it could support its body under the force of gravity whether in very shallow water or on land," said Farish Jenkins, professor of organismic and evolutionary biology at Harvard University and co-author of the papers. "This represents a critical early phase in the evolution of all limbed animals, including humans--albeit a very ancient step."
The new fossils were collected during four summers of exploration in Canada's Nunavut Territory, 600 miles from the North Pole, by paleontologists from the Academy of Natural Sciences in Philadelphia, the University of Chicago and Harvard University. Although the team has amassed a diverse assemblage of fossil fish, Shubin said, the discovery of these transitional fossils in 2004 was a vindication of their persistence.
The scientists asked the Nunavut people to propose a formal scientific name for the new species. The Elders Council of Nunavut, the Inuit Qaujimajatuqangit, suggested "Tiktaalik" (tic-TAH-lick)--the word in the Inuktikuk language for "a large, shallow water fish."
The scientists worked through the Department of Culture, Language, Elders and Youth in Nunavut to collaborate with the local Inuit communities. All fossils are the property of the people of Nunavut and will be returned to Canada after they are studied.
The team depended on the maps of the Geological Survey of Canada. The researchers received permits from the Department of Culture, Language, Elders and Youth of the Government of Nunavut, and logistical support in the form of helicopters and bush planes from Polar Continental Shelf Project of Natural Resources Canada. The National Science Foundation and the National Geographic Society, along with an anonymous donor, also helped fund the project.
I think you should check out his link. He's got us.
"You got us dead to rights. Your link
http://www.biology.arizona.edu/cell_bio/tutorials/cells/cells3.html
says right there in black and white that Darwin believed the body was made up of only one cell.
Or certainly not more than "more than one."
EXACTLY.
But NOW we know that Darwin was wrong, and NOW we know that the body was made up of TRILLIONS of cells.
You guys are just too easy, and I'm only a country bumpkin.
That's two things you are right about. Amazing.
The question is whether you did.
You have cited this link as showing that Darwin thought a human body to be made from a single cell.
http://www.biology.arizona.edu/cell_bio/tutorials/cells/cells3.html.
Nothing there says that. Never mind that, if it did say that, it would be wrong. It is a very sketchy outline of some major events in our understanding of cells. Darwin is not mentioned. Nothing supports the assertion that anyone at all thought large organisms were unicellular.
(Can Rev. Moon be far behind?)
Well … no, that won’t convince you. I doubt anything will. But really, if you want to take part here, please learn the simplest facts. Like, for instance, the century in which 1859 fell.
REFUTE, my links below and give me an excerpt with link. This is a challenge. Don't change the subject this time.
I’m not the one who’s been changing the subject. I’m the one who’s been posting the questions you’ve ignored.
Darwin convinced scientists to believe his theory based on antiquated information,
Substantiate that. Your link doesn’t.
.at that time, like we only have one cell, when we really have trillions, and when there are new discoveries, evo scientists just change the theories. PROOF of what Darwin once thought:
http://www.biology.arizona.edu/cell_bio/tutorials/cells/cells3.html - shows that they thought there was only one or a few cells
You know, I’d really like to post the whole page here … but I don’t want to get JR in trouble for a copyright violation. I will confine my answer to this: The page in no way supports any of your contentions. In fact, Darwin’s name doesn’t appear on it anywhere!
But NOW we know that the human body is made up trillions of cells.
http://websekolah.bharian.com.my/F1Sci/june15.html
So what? As I posted before, the Theory of Evolution does not stand or fall on the number of cells in the human body. Where do you get this stuff?
Is science EXCITING, though?? Science is ALWAYS learning something new(except for those stuck in the 18th century).
Or the 1st.
One cell! I don't need no trillions of cells. One will do very nicely. My granddaddy weren't no multi-cellular organism.
What Darwin knew....
Five evos against one IDer just to make it fair:
Dear Yahoo!: My 7th-grade class wants to know approximately how many cells make up the human body. David
Aurora, Colorado
Dear David: That's a very good question, and we applaud your class for its inquisitiveness. We knew there were a lot of cells in the human body, but we were hard pressed to put an actual number on it. It seemed like a fairly straightforward query, so we tried a straightforward approach and typed "number cells human body." Our results were numerous and informative, but after flipping through them, we learned there really is no consensus on the answer.
Some sources told us that the average adult human body is made up of "50 million million" (50 trillion) cells, while others put the figure closer to 10 trillion. Science NetLinks, a resource for science teachers, stated that there are approximately "ten to the 14th power" (that's 100 trillion) cells in the human body.
http://ask.yahoo.com/20020625.html
But alas, here's what poor ole Darwin thought:
The Cell Theory
When Schleiden and Schwann proposed the cell theory in 1838, cell biology research was forever changed. The cell theory states that:
All life forms are made from one or more cells.
Cells only arise from pre-existing cells.
The cell is the smallest form of life.
http://www.biology.arizona.edu/cell_bio/tutorials/cells/cells3.html - shows that they thought there was only one or a few cells.
Hey guys, remember how some of ya doubted me when I told you there were TRILLIONS of cells?
Another thing: How come there was no EUREKA! about this TRILLION cell discovery?
How come no Nobel prize, PatrickHenry?
Are the evo scientists trying to hide the truth?
Placemarker
It says life forms are made up of one or more cells. 'Life forms' includes amoebae.
Sheesh!
spe·ci·a·tion (spç'shç-â'shÉ™n, -sç-) n.
The evolutionary formation of new biological species, usually by the division of a single species into two or more genetically distinct ones.
In zoology, as in other branches of biology, subspecies is the rank immediately subordinate to a species. As an aside, do note that in botany a subspecies is only one of the ranks that will get a ternary name (see there), while in bacteriology, the terms subspecies and variety are usually interchangeable, see ICNB. Its one of the varieties of a species and can breed freely within the species population.
I did not give you examples of subspecies but examples of speciation. That you did not know the difference is the fault of your own opinion.
So where's the proof that this can happen?
You received it. At least 10 examples.
And please, no more games. It's a simple question, and it is the CORE of evolution. No game and you are wrong.
Games only make ME look good, and you don't REALLY want to do that, do you? :)
I don't play games but if you think someone could make you look good you might want to reread the posts. You are a legend in your own mind, fortunately that as far as it goes.
Are you sure?
From an excellent, but strangely hidden link: When Schleiden and Schwann proposed the cell theory in 1838, cell biology research was forever changed.
Heck, they ADMIT it's only a THEORY!!!!!!!!!
You're safe, PH.
Are you sure?
"Trillions" isn't "more" when talking about government spending ...
Prime?
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