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.
You wish.
I've taught children before, some learned some did not. I am sure you are aware that method will always defeat opinion and that the only answer opinion has for method is another opinion.
You wish.
State the method of science so I can know if we are speaking of the same thing. Your opined opinion is most often not science. Then state a scientific assumption by science.
State the method of science so I can know if we are speaking of the same thing.
Excuse me, but if I may Fester...just to help the discussion along...Fester argues that all is supernatural. That is, what science considers natural is supernatural.
I suspected as much. I am not interested in what Fester believes or in a opined opinion. However he is entitled to his philosophy that all is faith, belief, and opinion.
Science assumes an intelligible universe. Can you tell me, scientifically, how such a universe can come about without intelligence or design?
I do not argue that "all is supernatural." I argue that the distinction between natural and supernatural is scientifically arbitrary and thus not subject to scientific method.
Written 2000+ years ago, nor could he(God) have explained things.. that is physical things.. So what can be missed is that explainations have been limited to the most important things.. Spiritual things.. What good is it if you are a brilliant "scientist" and are cursed with spiritual "demons" of various sorts.. Like narcissim or selfishness.. or worse.. Successful at science but a failure at human life both personal and corporate....
There are things much more important than "science".. personally and corporately.. Arrogance says, that Jesus couldn't walk on water, but a reptile could decide to grow feathers instead of scales.. or that a stew of chemicals could form a lifeform.. When science doesn't even know what life IS, really....
For a collection of writtings(bible=library) written 2000+ years ago.. it stands alone.. Literally NO other belief in some God comes close to the bible.. written by about 39 people most of whom never knew each other..
When and If we ever find out what gravity is what good would that do.. Better transportation?.. some widget?.. more and cheaper energy?..Thats assuming we as humans could even understand the framework of this Universe, the foundation of it on our best day.. Engineered Art needs a user not a critic.. A grateful user.. Primates need to remember that they are primates.. You know a little humilty..
If true then Darwin was an ID'er.. You know intelligent design.. before it was called that..
Were you aware that you do post contradictory material with a great deal of regularity.
You're a DU troll aren't you? That's their standard technique. BTW, if you'll give me your name over at Smirking Chimp I can look up your stuff and see if you do the same thing in front of your friends.
Intelligent design fits objective reality handily from both an inductive and deductive standpoint. It takes a philosophy of some kind to explain it away. Let an evolutionist fill in the blank: "The presence of organized matter performing specific functions is best explained by . . ."
They do not have an answer. They pretend such an answer resides outside the realm of science altogether. To a degree it resides outside the realm of absolute certitude in this life. So do many other things science contends with. Science does not even know how many rubber bands are manually discarded each year. I hardly think it capable of reconstructing genetic history on the basis of morphological similarities.
Besides, it stands to reason that common ancestry could easily be mistaken by science for a common Creator.
I argue that the distinction between natural and supernatural is scientifically arbitrary and thus not subject to scientific method.
Fester, I can post a quote where you state that everything is supernatural. At any rate, I'll bite. Please elaborate on your distinction between natural and supernatural, assuming you now maintain there is one.
(That is your opinion. Math is used to "describe" physical and non-physical elements, and it is the very foundation of science.)
Get this! Science originated as a philosophy. It was the philosophy of nature.
It does? Find me such a stated assumption by science and not your opinion.
Bulk and presort rate mail was packaged in 10 letter units, and wrapped with rubber bands. This resulted in USPS (which has half the mail in the world, and virtually ALL of the direct mail advertising) using most of the rubberbands in the world.
In fact, entire rubber band factories were built for the sole purpose of providing sufficient rubber bands to USPS.
The number "scrapped" each year could be deduced quite readily. I vaguely recall a statistician friend of mine doing that but I don't remember how many it was.
I think you should use an example better in tune with the purpose you are attempting to serve. Rubber bands ain't it.
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