Posted on 04/02/2009 4:46:24 PM PDT by GodGunsGuts
Envying the Tooth of the Sea Urchin
March 31, 2009 — Did you know the lowly sea urchin has a tooth? It’s not just any tooth: it’s “a remarkable grinding tool,” according to a team of international scientists. They even used the word “exquisite”
in the title of their paper in PNAS.1 Humans might benefit from knowing more about this tool. “The improved understanding of these structural features,” they said, “could lead to the design of better mechanical grinding and cutting tools.”
The sea urchin “tooth” is not really a tooth, but a hard rod with a serrated edge used for crushing the animal’s food (see description at Univ. of Wisconsin about the work of Pupa Gilbert, one of the co-authors). The urchin tooth, which grinds down hard limestone, has the hardness of teeth in higher animals. “Even though the tooth is composed almost entirely of calcite, it is used to grind holes into a rocky substrate itself often composed of calcite,” the abstract from the paper reads. It continues—
Here, we use 3 complementary high-resolution tools to probe aspects of the structure of the grinding tip: X-ray photoelectron emission spectromicroscopy (X-PEEM), X-ray microdiffraction, and NanoSIMS. We confirm that the needles and plates are aligned and show here that even the high Mg [magnesium] polycrystalline matrix constituents are aligned with the other 2 structural elements when imaged at 20-nm resolution. Furthermore, we show that the entire tooth is composed of 2 cooriented polycrystalline blocks that differ in their orientations by only a few degrees.The slight misalignment and interdigitation appears to provide a functional advantage, they found. It provides a corrugated edge that fractures along its cleavage planes so as not to fracture the tooth but actually sharpen it as it cuts. “We also note that in this model, the edges of the individual plates would remain anatomically sharp due to cleavage along the {104} planes, and the cleavage would probably not propagate through the whole tooth tip because of the small misalignment between neighboring plates.” In other words, even the apparent misalignment has a function. They said, in conclusion,A unique feature of the grinding tip is that the structural elements from each coaligned block interdigitate. This interdigitation may influence the fracture process by creating a corrugated grinding surface. We also show that the overall Mg content of the tooth structural elements increases toward the grinding tip. This probably contributes to the increasing hardness of the tooth from the periphery to the tip. Clearly the formation of the tooth, and the tooth tip in particular, is amazingly well controlled.
The mature sea urchin tooth possesses incredible structural and compositional complexity. Here, we show the presence of crystalline blocks composed of 3 different coaligned elements: needles, plates, and polycrystalline matrix. We also show that the tip, and presumably the whole tooth, is composed essentially of 2 such coaligned blocks that differ in their orientations by [less than] 6°.The blocks are also interdigitated in the tip. Furthermore, the Mg concentrations increase toward the center of the tooth tip. We propose that all of these features contribute to the grinding capability of the tooth. A deep understanding of the structural
design features of the tooth tip sheds light on the manner in which one crystalline phase, calcite, can be tailored to fulfill grinding and self-sharpening functions that enable the tooth to be used to grind holes into a substrate that is also composed only of calcite. Much can be learned from the sea urchin tooth that can be applied to the development of improved grinding and cutting tools.
USA, published online before print March 30, 2009, doi: 10.1073/pnas.0810300106.
All together, everyone: how much was said about evolution in this paper? ZILCH! Instead, they used the D word design: they wanted to gain a “deep understanding of the structural design features” of this “exquisite” grinding tool to learn how we might tailor our own bottom-up nanofabrication of crystals to fulfill functions useful to us. This paper had intelligent design all over it – in the research, in the understanding, and in the application.Show this to your biology teacher and tell him or her that “Nothing in biology makes sense except in the light of design.”
Ping!
Design???
How unscientific!
Why is it everybody’s suddenly into beheading?
Ask the the dissidents who have been slaughtered by the Temple of Darwinistic Materialism:
http://www.slaughterofthedissidents.com/index.php?p=20case_studies
Money quote:
Show this to your biology teacher and tell him or her that “Nothing in biology makes sense except in the light of design.”
Try telling that to the engineers!
Incredibly well-suited features are, just by themselves, difficult to imagine randomly appearing for use by the animal that needs them. Especially when the evolutionary bioligists tell us that nothing induces these mutations, they just “randomly” appear with the most suitable surving.
When one couples this improbability with the observation that each of these specially suited features require incredibly complex physiological support systems interonnected around them to function, it boggles the mind that such a series of accidental benefits could inure to any creature.
But, wait, there’s more! Then, we are told the same thing happened in every single creature. Hmmm.
Actually, there is mounting evidence for directed mutations, which makes matters far worse (I would say fatal) for RM + NS!
I like how every reply in this thread is not about the sea urchin but posts against evolution.
They just can’t help themselves...God’s creation demands it!
The hits just keep coming...
“Directed” mutations? This in the face of the need for this to be utterly, fully, undirected. I would hate to have to deal with the mental dissonance this creates.
Not so. The sea urchin is clearly the subject. It is just difficult to contain a discussion about one item, which holds implications about hundreds, no millions of other items when the prevailing “religion” wants us to be sheeple and trust them. Random events give rise to billions of well suited structures. It begs the extended comment.
You really need to get a life.
Sea urchin tooth on loan from GODDDDDDD.
Natural selection isn’t random. Genetic mutations are random.
Understanding evolution takes a gross simplification. Let’s say there are 100 tiny creatures.
Their genetic code causes them to glow red 80% of the time and glow green 20% of the time.
Suddenly because of an environmental change there’s a series of events which cause a 15% chance of death to a red one and a 10% chance of death to a green one. Without any genetic mutations chance of survival will be equal for all the creatures. If one has a genetic mutation for it to glow red 90% of the time it has a lower chance of survival than the others and that genetic code will be eliminated. While on the other hand one that has a 30% chance to glow green will have a higher chance of survival, maybe it will die anyways and that genetic code will be erased, but through odds eventually the surviving genetic code will favor a green glow without ever having a “design” behind it.
Macro evolution is more complex and in stages. If humans suddenly were placed into a water environment natural selection would favor people with a genetic mutation of long fingers and webbing between digits. Both of which are genetic mutations which already exist in people. In small increments this will (assuming it follows a logical path which it doesn’t always) lead to very webbed hands and long flat extended fingers.
Wow. All those people slaughtered. And yet they still live. Amazing.
Wow what an imagination you have!
None of it has anything to do with evolution. The plan has been in place since the beginning, and nothing will deviate from it. So few species, and such magnificent complexity; just the opposite of evolution.
Yeah I do have a very large imagination, thanks.
Please re read before you post. I did not say natural selection was random. I said the appearance of the mutations were random. Notice your little creatures first have to have the red or green glows appear for no reason whatsoever, for the natural selection to operate and prefer one over the other.
It is that “appearance” that is so glossed over. Especially, considering that the little “glow” may be a 500 element structure and that it could not function on its own. The glow requires an operating blood supply, healing system, aspiration devices, temperature monitoring system, immune system, and four hundred other “in place” mechanisms all working in perfect harmony BEFORE the glow would even survive the first day.
Macro evolution’s main schtick is common descent. Everything came from one original organism. That, by definition, begins the skepticism about the six hundred billion interactive mechanisms which had to appear. When the probability of one of these arising is set against the need for ten thousand supporting systems all occurring within seconds of each other, or none could have survived long enough to get selected, thoughtful folks see what is being peddled.
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