Ear in sight. The middle ear evolved as primitive fish (top) became more advanced (bottom): The spiracle enlarged as the proportions of other bones (yellow, blue) changed.
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." |
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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.
Why do scientists continue to deny the fact that God created mankind? There is more scientific evidence that points to that fact than the scientists can ever make up for their imaginary beliefs. Our ears never breathed...what a bunch of hooey!
Preach on!
You really believe this junk science?
All these "discoveries" and "facts" seem to be set 370 million years ago. I think they do that so that not as many people will laugh at them.
That kind of ignorant thinking needs all the slaps in the face and kicks in the butt educated people can possibly dish out!
Hogwash! Put forth your evidence.
If a couple of space aliens walked out of a UFO on to your lawn, you'd "prove" the above fact to them how, exactly?
Now available in a new flavor: "Where are the transitional ears???
Ear in sight. The middle ear evolved as primitive fish (top) became more advanced (bottom): The spiracle enlarged as the proportions of other bones (yellow, blue) changed.
It's because this particular fossil was found in rock strata dated by multiple means to be 370 million years old.
To be ignorant is curable. The exaltation of ignorance is a life being wasted in slow motion.
I wonder if God gets tired of you telling Him how He did it.
Let me translate the article for you:
I don't want there to be a God. I don't want to be responsible to a God. I don't want to think that maybe I'm not the highest thing in the Universe. But more than anything, I don't want you to think that their is a God who is smarter than we scientists because in our little world, WE ARE GOD.
I thought it was common knowledge that our ears evolved from the gills of fish.
300+ million years ago? What's so special about this? Evolutionary Biologists talk out of their asses to this day.
Well, that certainly explains a few things. Everytime I get an earache, three days later - BAM - I get bronchitis or pneumonia. I am AKA 'the wearer of the dorky hat with the earflaps on a sunny day guy' (which was far too long to use as a screenname).
Get over yourself. God and evolution are not mutually exclusive.
And for how many generations did "dinosaurs" have to live with lousy "arms with feathers" before they became wings?
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