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.
2 more missing transitionals!!
~Palaeontologist Thomas Martin of the Senckenberg Research Institute in Frankfurt, Germany.
Don't feed the platypi!
Looks like now man evolved from the platypus. If no other creature has the triple boned ear, it must have been. /Creationist mocking off
Think of it this way -- evolution doesn't deny God -- it shows us all the wonders of His creation and how He made things. That's what science does -- helps us get more and more in awe of God. Those that try to say science replaces God aren't really great scientists -- look at Einstein, he was a devoted worshipper.
"Do people really not understand that evolution involves random mutations and then the death of all non-mutated individuals and their offspring?"
Everything individual dies, but some individuals manage to reproduce themselves beforehand. Also I think your argument above ignores crossover.
"Gould's idea of rerunning the tape of life is not hypothetical; it's happening all around us. And the result is well known to biologists — evolutionary convergence."
THINK for yourself! If you were to come upon an object on Mars in the shape of a polished table or even a perfect triangle, you would immediately recognize the probability of intentional design. Why, then, do you fail to see the designer's hand in the breathtaking complexity of the simplest one-celled organism?
I have found that ardent evolutionists invariably point to what someone else says, rather than using their own power of reason.
Bless you for posting that.
Cool! :-)
:-} I'll bet.
Hi! Actually, I was just posting those quotes to show, in the evolutionists own words, the inconsistencies of evolution theory. The slow, methodical march of RM/NS seems to be insufficient to account for the complex morphological transformations we see in nature.
I agree with what you said, btw. :)
Agree. Evolutionists have to deal with many stubborn facts. Such as the predominance of sexual reproduction. How would a successfully mutated individual advantage its offspring by mating with a non-mutated individual and diluting or eliminating its genetic advantage in that offspring?
I was thinking the other day about all of the distinct breeds of dogs that were -- yes -- designed by human intervention. What do you think would happen if all humans were suddenly removed and those dogs ran wild and interbred? It is most likely that you would soon end up with the conglomerated brown/gray mutt that you see hanging around in poor third world countries. In other words, the dogs that may have developed some survival "advantage" over the others would nonetheless copulate with the first hot bitch -- be it chihuahua or doberman -- that they found. That's what undirected randomness involves.
I understand perfectly the import of your posting. It is amusing that ardent evolutionists seem to find the article supportive!
"I have found that ardent evolutionists invariably point to what someone else says, rather than using their own power of reason."
Point to what somebody else says, like say, 1 chapter of a 1-bazillion year old book written secondhand by a few dozen different people?
Platypus Ping
I thought a platypus was the love child of a near-sighted beaver and a seductive mallard.
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