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." |
Just throwing it out there...
Macro Evolution violates the second law of thermodynamics. Nothing gets more complicated without external influences. We did not evolve from some ooze.
Micro evolution yes. Macro no. I leave it to your own belief system to determine how that happened.
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Guess what! There ARE external influences on species!
One of them is an enormous nuclear generator in the sky.
;->
Ah a sense of humor. I didn't think you had it in you.
Fraud is rife in scientific academia.
Insanity, however, is still there ...
I think that was a joke.
You guys spend the rest of the evening feeling smug about how your scientific knowledge trumps my common sense. Be sure that you don't forget that your just trying to make yourselves feel better. Perhaps you could get together and write an article on how our noses used to be appendages utilized to help us swing from tree to tree!
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Common sense, in terms of science, is usefully described as what we knew about 2 centuries ago.
Once it was common sense that heavy objects fall faster than light ones. Once it was common sense that if you drop an object from the top of a mast of a ship, it would fall behind the ship. Once it was common sense that an object needs a constant force on it to keep it moving at a constant speed. Once it was common sense that time was absolute, and moving quickly wouldnt affect the rate that time went. Once it was common sense that we could know both where something was and how fast it was going.
I will take scientific evidence over common sense any day of the week.
And you trust the PEERS? I'm glad America moved beyond the peerage. I don't need barons and squires and such--
Fraud is rife in scientific academia. The stakes are high--prestige, money, status, money, careers, money, tenure, money. A scientist is just as likely as anyone else to fall to tempation.
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Ahhh.. the money! I know that when I was in academia, you could hardly find a parking space in the biology faculty parking lot. All the spaces were taken up with Jaguars, Bentleys, Rolls Royces and the like!
Me: Dinosaurs.
Creationist: La la la la la can't hear you!
Me: Neanderthals.
Creationist: La la la la la can't hear you!
Me: The X-Men mutants.
Creationist: Whoa, cool!
You guys spend the rest of the evening feeling smug about how your scientific knowledge trumps my common sense.
I saw no common sense in evidence from you.
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From creationists, common sense is neither.
Okay. Everybody was biting their tongue and holding off the jokes ...
"Virtual Ignore for trolls, lunatics, dotards, scolds, & incurable ignoramuses"
FR is badly in need of an anti-spam feature that allows one to filter out the broken record rants of people who belong in the crank.net hall of fame.
That's why the Grand Master pays you the big bucks.
Of course, from what I can see, you are so indoctrinated into the flat earth society, that all you can do is cover your ears and eyes and scream "la,la,la,la" like a little kid trying NOT to hear something they don't want to hear.
Evolution happened and continues to happen. This is a fact just like gravity is a fact (we can't "prove" gravity, we don't know WHY it works....but experimental testing and the fact that we are all still attached to the earth and are not thrown off into space due to rotational velocity is a pretty darn good indicator of its' existence). Evolution is the same way. All those fossils are not part of a great conspiracy to deny your God. Rather, think of them as small pieces to the huge puzzle God left here in order to give us little insights into his mind and his thoughts, desires, processes and goals for us. To deny this evidence, is to deny the wishes of YOUR God.
If God wanted you to hide your head in a hole in the ground and remain ignorant of his great works of creation, there would only be animals. Man was allowed to evolve from the lower animals in order for God to start educating his children - to pass along his knowledge - like most normal families do - from Adult to child - or in this case - from God to Man.
Evolution happens. Accept it and be closer to your God.
But even as these "imperative vs. subjunctive" criticisms abound, presumably to point out the "weakness" of science, how many times have we seen anti-science posters complaining that evolution is being taught as fact when "it's only a theory?"
And they seem to be proud of it. (Shaking head in disbelief)
ROTFLMAO! Best line of the thread!
That's good! I'm going to steal it. LOL!
You have it backwards. We (the human race) started out thinking the universe was young until the evidence became so overwhelming that we finally had to admit it was billions of years old.
Evolution, the tool of the quasi-scientist.
Nope. The "Young Earth" idea far preceded Darwin’s time. I cannot interpret what time span "old" means in the Bible.
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