The jaw of Teinolophos trusleri catches the ear bones in the act of separating from the jaw.
Posted on 02/11/2005 6:49:09 AM PST by PatrickHenry
Triple bone structure arose independently in platypus and humans.
Listen up: mammals seem to have evolved the delicate bone structure of the middle ear at least twice. The surprising discovery comes from a fossil, found off the southern coast of Australia, that belongs to an ancestor of the platypus.
Modern mammals are unique among vertebrates for possessing three tiny bones in the middle ear. The malleus, incus and stapes (commonly known as the hammer, anvil and stirrup) work as part of a chain that transmits sound towards the skull. Birds and reptiles have only one bone to perform this function.
Because the mammalian arrangement is so complex, scientists believed that the set-up had evolved on just a single occasion, in an ancestor that gave rise to placental animals (including humans), marsupials and monotremes (such as the duck-billed platypus).
All this changed when James Hopson, a vertebrate palaeontologist at University of Chicago, Illinois, took a trip to Australia. There he met a team of researchers including Thomas Rich of Museum Victoria in Melbourne.
The jaw of Teinolophos trusleri catches the ear bones in the act of separating from the jaw.
Rich and his colleagues had recently unearthed a fossil of Teinolophos trusleri, an ancestor of modern monotremes that lived 115 million years ago. "He said he had some new Teinolophos specimens and when he showed them to me I almost fell off my chair," says Hopson, an author of the study, published this week inScience [Rich T. H., et al. Science 307, 910 - 914 (2005)].
Hammer time
Palaeontologists believe that the middle-ear bones of modern mammals once belonged to the jawbone and later separated to adopt their present location. This is supported by the fact that the middle ear's bones associate with the jaw in the early development of modern mammalian embryos.
What makes theTeinolophos specimen surprising is a large groove in its adult jawbone, which indicates that the smaller bones had not yet detached.
Teinolophos lived after monotremes split from the placental and marsupial mammalian groups. Its jawbone structure, along with its place in the evolutionary tree, hints that a common ancestor to all these mammals lacked the special three-bone ear structure.
This means that natural selection must have driven the same rearrangement in independent groups, after the monotreme split. "Some embryologists had the idea that it might be convergent but nobody really believed this," says palaeontologist Thomas Martin of the Senckenberg Research Institute in Frankfurt, Germany. "I was quite shocked when I heard that such a complex morphological transformation happened twice."
The discovery will compel many experts to rethink their appreciation of mammals' common evolutionary heritage. "Until now it was considered to be one of the most important shared derived characteristics of modern mammals," says Martin.
No chip on your shoulder, no sir.
How 'bout you? Engaged in a little angelism or just don't care?
I don't think I presented a "pro" position for anything. I have a position. But, we're on what your "evidence" is - are we not. Why is it that suddenly you'd rather talk about someone elses position. Why do you find it suddenly necessary to change the subject. And I don't care what you want to call "mountains" of evidence. I think we just went over what evidence means and what the reach of it is, didn't we. There is no such stricture being observed in your ranks and your conclusions become more a matter of belief than of demonstrable anything in exclusive support of your position.
I'm sure you have a real problem with the Bible and it's morality. Guys like you usually do. That doesn't make your case; but, largely seems to be the reason you think yourselves above everyone else and above reproach. That has been the operatoinal assumption of your side for quite sometime. You've simply overplayed your hand and the reach of what you call evidence hasn't met your grasp. So a whole school of propaganda has sprouted up over time to defend the lack of evidence as though it were conclusive. History has caught up to you. If you can't stand the Bible, you'll have to demonize it and those who do believe it without the club of belief masquerading as science and show yourself for what you really are.. which appears to be, at least, an intolerant snob and at worst a bigot. And our tax dollars don't have to fund that crap.
"I don't think I presented a "pro" position for anything. I have a position. But, we're on what your "evidence" is - are we not"
I don't think you have, either. The evidence for evolution is there.
Argument with no evidence is the specialty of those who attack evolution because their interpretation of the Bible leads them to believe evolution cannot be true.
Unless you can give evidence refuting evolution or evidence supporting a contrary position, you cannot honestly participate in the debate attacking it.
"I'm sure you have a real problem with the Bible and it's morality. Guys like you usually do"
Guys like Christian Ministers have a real problem with the Bible?
You can't be serious.
You're arguing with Kent "Dr. Dino" Hovind there.
"What are the two are three biggest weaknesses of the modern evolutionary synthesis?"
I don't think there are any serious weaknesses. If there were, evolution would not be a scientific theory.
There are areas where more information is desireable, like the Precambrian fossil record. But it is unlikely that a huge amount of fossils will be discovered from that period, in any event.
Common descent is a foundational principle. It has been upheld by all the data. In other words, all life is related to each other somewhere along the tree of life.
He doesn't seem as blockheaded as Dr. Dino.
"appears to be, at least, an intolerant snob and at worst a bigot. "
Name calling is not very Christian. I run a homeless ministry in the inner city. I don't think many can call me a bigot or intolerant with any basis. In fact, those who do are probably more likely to have those attributes than I.
He uses the same arguments (down to the exact same wording) as Dr. Dino. And, after you spar with him for a bit, you'll see Havoc can be just as thick as the aforementioned charlatain.
I don't think that's true. Punctuated equilibrium is a scientific theory, but mainstream evolutionists seem to identify substantial weaknesses in it.
Don't you agree?
Well, you keep saying that; but, as I've noted - what you call evidence continually isn't much better than what this article presents and in some cases it's worse. You present a bone, then give us a book synopsis of the planet millions and billions of years ago .. based on a bone. There is a limit to the suspension of disbelief just as there is a limit to what you can get from a bone (and that's before discussing viability of samples and whether such exist). The wild books of hypothesis from your belief system are not evidence. The bones may be evidence; but, evidence for what is quite another matter. And especially in light of the great flights of fancy we're constantly entreated to as though they were fact (merely because they are worded in that fashion).
Lastly, no, you have your argumentation technique 180 degrees reversed from the rules of logic. You present something and it is your burden to prove your case. It does not become my burden to disprove it. Scientists of your religious persuasion have been trying to use the term "science" to get by with using endless hypotheticals to construct their own belief system and force it on everyone else. The extent of their proof is their hypothesis. If you can't do better than that, you better surrender here, cause as I noted before, it's only going to get worse. America is fed up with the abuse.
"Problems that you almost never see in quadrupeds..."
Fortunately for those few quadrupeds that do suffer, there are caring humans ready to help.
http://www.animalchiropractic.com/
I feel your pain horsey
Uh, there were recently men "of the clothe" posing as Christians in another religion that were pedophiles. You aren't seriously going to argue that evolution is ok because men perporting to be Christian agree with it..
Name calling, no, It's merely putting appropriate labels with the condition while noting the appearances. When people snobbishly look down their noses at Christians with distaste and reviling them because of their beliefs while holding themselves up as intellectually superior, the question is begged in and of itself. I'm not name calling, I'm labeling behavior for what I see in it and feeling nothing about it either way.
Christ did the same thing. Want to tell me how unchristian he was?
LOL The same wording? What do you mean? Do you think he just cuts and pastes from the Dino site.
I resent your implication that the Gospel of Jesus Christ has anything to do with your misinterpretation of Genesis.
You sir, are no gentleman. You better have some evidence before you call anyone a pedophile. I have raised 4 successful children and have three grandchildren. I meet the qualifications for an Elder in 1 Timothy. Do you?
Plus, I've accused him in the past of being Dr. Dino and he's never denied it.
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