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." |
How does a microbe trip on sand? What are you tripping on? Do you even know what a microbe is?
Very
Intelligence, like beauty, is in the eye of the beholder!
Apparently, you can't see very well!
That is simply all he comprehends. Every explained shadow, every explained sound from the sky, to him, is an attempt to disprove God. Heliocentricity was seen as an attempt to disprove God as well. Ignorance seems to be a strength to many, something to aspire to.
"Now if somebody could explain where the first cell came from."
Not this crap again. You post the same thing, every thread. It gets answered, then you claim nobody will answer it. Please, get a new shtick.
Wow -- great tag line material
This statement puts into doubt any objectivity on the part of the researcher.
His statement is objectively correct.
It appears the motive behind the work is not related to advancing scientific knowledge, but sticking a hot poker in the eye of those he detests.
It appears you are slandering his motives based on the fact that he makes a correct statement which you find uncomfortable for your beliefs.
And nowhere have you established in any way, nor is there anything in the article which suggests, that he "detests" people like you.
It looks to me as if you're engaging in either psychological projection, or paranoia. Maybe both.
The article didn't mention religion at all. It said "creationists", and the "creationists" have been saying all along that it isn't about religion. Are you finally admitting that they (and you, apparently) have been lying to us all this time?
And I don't know if you've heard, but it turns out that trees produce methane (lots and lots of it) even when they're alive and not decaying. Global warming caused by global greening. A whole slew of biochemists missed out on that until just this week.
But our ears could smell--until we evolved. That's according to the peers who pitch their wares here--
I think it's time for a group hug. |
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!
Wow, are *you* confused. No, that's not the "party line", that's your goofy misunderstanding.
Yes, the birds and the bees and the flowers and the trees came from...... ....comets, or 500 miles underground. Whatever.
Actually, they came from elsewhere. Take your straw men elsewhere.
And of course plenty of your tax dollars are going into research on this.
As it should. It's important research.
Why? Remember the "primordial soup" of the early earth, made up of NH3 CO2, H2O that we were told gave rise to the first life.
By whom, exactly, and when? Be specific.
Well it should have left behind a lot of nitrogen bearing sediments. Guess where they've found these sediments? They haven't. Afdter 50+ years of looking. A bit embarassing.
That's not embarrassing at all.
But don't lose faith. We'll find it on comets.
Your sarcasm is a poor substitute for knowledge. If you can't hold your own in a science discussion, don't bother.
Yep.
lol!!!
Nothing gets more complicated without external influences.
How does a tree get all of that wood out of a tiny little acorn.
We did not evolve from some ooze.
There was obviously some ooze involved in the evolution of your education!
You should check out the pro-smoking threads then. Logic and science as we know it are often incomprehensible. LOL!
No it doesn't.
There's a fictional, non-existent "Second Law of Thermodynamics" invented by a variety of Creationist liars that bears no resemblance to the REAL Second Law of Thermodynamics, which you may be thinking of.
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