Posted on 01/18/2006 6:10:34 PM PST by PatrickHenry
Our ears could have started evolutionary life as a tube for breathing, say scientists, after examining the ancestral structure in a 370-million-year-old fossil fish.
Evolutionary biologists are intrigued by how complicated sensory organs evolved from structures that may have had completely different uses in ancestral creatures. The bony structures in ancient fish, which at some point turned into ears, for example, appear to have had mainly a structural function, bracing the cheek and holding up the jaw. How exactly they made the transition to their role in hearing has proved a bit of a mystery.
The ear is a relatively easy organ to study. Its evolving bones have been preserved as fossils, whereas the soft tissues of other specialized features, such as eyes and noses, have long decayed.
So Martin Brazeau and Per Ahlberg of Uppsala University in Sweden decided to take a close look at the ear-like features of an ancient, metre-long monster from the Latvian Natural History Museum in Riga. Panderichthys was a fish, but is thought to be closely related to the earliest four-limbed tetrapods that eventually climbed on to land and gave rise to modern vertebrates.
The researchers examined Panderichthys and found that the bony structures in its head combine features of fish and tetrapods, capturing a snapshot of evolution in action. "It's neat to see that transition," says Hans Thewissen who studies the evolution of the ear and other organs at Northeastern Ohio Universities College of Medicine, Rootstown.
Half-way house
Ancient fish have a narrow channel from the roof of the skull into the mouth, known as a spiracle, which is bounded by a long bone known as the hyomandibula that braces the cheek. In tetrapods, the equivalent bone is stubbier, a step towards the stirrup-like stapes bone that helps to transmit sound waves into our skulls.
The team found that Panderichthys has a wide, straight spiracle rather than a narrow one, and a shortened hyomandibula. They report their findings in Nature1.
Some have previously speculated that our ancient ears may have had a role in breathing.
On the basis of this new fossil evidence, the team speculates that the widened spiracle may have served Panderichthys much like the breathing holes used by modern-day sharks and rays. These allow the fish to inhale water over their gills while lying on the seabed, and avoid gulping in grit through the mouth.
| The demonstration of an organ evolving provides tangible evidence against the idea, put forward by some proponents of creationism, that sensory organs are so intricate that they must have been designed by a higher being. Brazeau says: "It's a slap in the face to that kind of thinking." |
My problem is the White Coat Sainthood and this hushed tone of awe in the Temple of Science. You wouldn't dream of granting it to a physician (as well you should not)--why a PhD evo-biologist or cosmologist or archeologist? They are the least accountable of scientists, because how can you hold whimsy and speculation to account?
All I can say is--spend a little time in academia to know of what I write. The gnawing anxiety for the next grant--the need to publish-publish-publish any nonsense just to satisfy the university politicians who are more interested in word count than substance--there is a lot of psychic pressure.
What a flake!
Could be it wasn't in their genes. Could be due to various selective pressures. Could be it wasn't advantageous.
I suggest reading a couple of good biology texts before getting on these threads.
But still larger than an wannabe.
We can't have a good evo thread without lots of evos telling people to shut up.
Why is that proviso particularly operative against THIS article? There's less money available in paleontology (and evolution related subjects generally) than in most scientific fields. Consequently there is LESS fraud. In fact fraud is extremely rare in evolution related fields, as is evident because it would be played up by the press whenever uncovered there. (Exception: fraud by entrepreneurial fossil vendors, although their fraud is almost always exposed BY working scientists.)
Fraud is most common where the most money is, thus the vast majority of scientific fraud occurs in bio-medical fields.
You know, the ear could of evolved from mothers pulling their kids up by the side of the head. I speculate that this pulling motion hurt the kids and hearing evolved as a kind of early warning system that let them know when their mom was coming to pull on their head.
Now I'm an evolutionist. Pay me.
Shut Up. (There; happy now?)
God did create evolution. And it was designed to work that way. imho. LOL!
Which Christopher Reed?
The UC Riverside Chemuist, the Canadian actor, the UC Berkley historian, or the English Journalist? I'd like to know where to sent the "Get well Soon" card.
They don't, and there aren't any irreducibly complex organs.
Wow. You are really upset. What happened to you to make you feel this way, if you don't mind my asking? Your arguments aren't arguments, they are emotional outbursts. It reminds me of somebody lashing out at someone or something that has hurt them, and badly. I honestly do not know how to respond. I wont pursue this conversation any further, if you'd rather.
Your statement is odd since your main argument against science seems to be claims of rampant fraud. Physicians commit FAR, FAR, FAR more scientific fraud than evolutionists, cosmologists or archaeologists.
Yeah and evidence shows most Democrats can still talk out of their rear ends. :)
YEC INTREP
That's because you can't catch fraud you can't prove. You can't prove or disprove a speculation, intellectual playfulness and hijinks, but you can prove that a drug kills people when you have said it helps people. (biochem--pharms) I'm glad you brought up pharmacology.
I'm interested in them as investments--and as evos are so fond of telling people "go shut and read"--evos might take instruction from the way that pharmaceudicals are researched and written about. All those "maybes" and "hopes" and "possibilities" and "probablities"--all those cautious qualifiers because errors are so deadly.
But more relevant than a couldabeen.
Did you just go through a divorce from a scientist? Man, you are one bitter and ill-informed person, and it seems you hate science.
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