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.
It absolutely does. I'm not impressed so far.
Learn the method of science. It presupposes no such thing, life can be observed as a fact unless you think you are dead. It does not even address a presupposition of creation. The theory addresses what it states not what you suppose it should state. There is no corundum of creation for science. If you can provide the observed material fact of creation, science will explain it and thank you for it. You will be the most famous man that ever lived.
Occam's Razor is, in effect, a restatement of the principal of parsimony. It can be stated variously as -- one should not increase, beyond what is necessary, the number of entities required to explain anything -- or -- one should not make more assumptions than the minimum needed.
Since the reflection of these systems would imply an intelligent cause to a reasonable person observing the result, the simplest explanation is that it was created and guided.
Although creationists repeat on a regular basis that the "simplest explanation" is creation ex nihilo by a supernatural agent, and that this supposedly "simple explanation" is consistent with Occam's Razor, it is in fact a direct violation of Occam's Razor.
This "simple explanation" involves the introduction of an invisible, undefined, unexplained, and inexplicable entity -- thus adding (or superimposing) on that which is being explained an unnecessary entity or an additional assumption that is itself incapable of explanation.
You mean its only a opinion.
Truth is an absolute, not a law... You can break a law, but you cannot break an absolute.
Truth is truth, for all things in all places in all time. Truth is the same absolute for everyone.
Your premise is false, and you know it.
Scientists are not the ones who cling to pet explanations against all contradictory evidence. All scientists have been taught that all science is provisional. If they stray from that dictum, they done screwn up. Most scientists will fight very hard against an upstart model in support of a comfortable model which has been shown to function well. However, those same scientists will accept such a new model once it has been shown under extensive trial to function better than the one they defended.
To a creationist, simple means the quickest way to end inquiry.
And the sun shines more brightly on those lucky individuals who have access to the absolute truth.
yes, basically - though I'd go a little further and posit that the "indications" of the art must be taken seriously within the art by the inhabitants of the art.
But, of a truth, I see the young earth creationist's difficulty as a matter of doctrine - most especially, how these passages are discerned:
So also [is] the resurrection of the dead. It is sown in corruption; it is raised in incorruption: It is sown in dishonour; it is raised in glory: it is sown in weakness; it is raised in power: It is sown a natural body; it is raised a spiritual body. There is a natural body, and there is a spiritual body. And so it is written, the first man Adam was made a living soul; the last Adam [was made] a quickening spirit. Howbeit that [was] not first which is spiritual, but that which is natural; and afterward that which is spiritual. The first man [is] of the earth, earthy: the second man [is] the Lord from heaven. As [is] the earthy, such [are] they also that are earthy: and as [is] the heavenly, such [are] they also that are heavenly. And as we have borne the image of the earthy, we shall also bear the image of the heavenly. I Corinthians 15:4248
Of those who see him as the first mortal man, there are some who believe God created an old looking universe about 6,000 years ago (Gosse Omphalos hypothesis) and there are some who believe the physical evidence will comport with a 6,000 year age. But both are a statement of faith and facts cannot trump Truth.
For me there is no inconsistency with the time involved due to inflationary theory and relativity, i.e. 6 equivalent days at the inception space/time coordinates are equal to approximately 15 billion years at our space/time coordinates. Also I have no problem with Adam, since I discern Genesis 1 and 2 speaking of the creation of both the spiritual and the physical worlds that Adam was banished to mortality in Genesis 4.
The story is now on AOL News: http://articles.news.aol.com/news/article.adp?id=20060406093109990001&ncid=NWS00010000000001
This is a relatively common overstatment. While I cannot, of course, put a precise percentage on it, I would guess that truth is non-absolute, or relative, in greater than 50% of circumstances. As a rudimentary example (from which you can extrapolate any number of additional examples), what is the "true" way to join two boards together at right angles?
Another way of dealing with this quandry is to admit one doesn't know everything, and possibly to admit that one isn't even capable of knowing everything.
My beef is with those who distort or deny physical evidence in an attempt to prove something that they cannot possibly know.
That's simple logic.
Claim something less than universality and you're OK.
I certainly never claim universality on anything ~
Now, does Christianity argue that there are certain absolutes? Sure ~ but in the spiritual and moral sense.
It might lend some credibility to the notion that life started from non-life and ended up with the vast diversity we have now.
Not sure why that applies to cows ~ that's why Jews eschew the consumption of cheeseburgers.
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