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Author Topic:   How is DNA even possible anyway?
Doofy
Inactive Member


Message 1 of 14 (144113)
09-23-2004 2:26 PM


Hi guys, I'm an undergraduate biology student at a north Texas university. Today in one of my classes we were talking about DNA replication, and part of it failed to make good sense to me.
What does current evolutionary theory say about a situation like the following: How DNA came into being in the first place, when it is made of bases, but in order to replicate new bases have to be constructed (from parts that we get from food, I guess), but the DNA contains the information that tells cells how to construct bases.
There are other kinds of paradoxical sounding questions I have seen in biology classes that I can understand. For example, I understand the concept of how a species can radiate to a habitat not taken by another species, then slowly change over time to take on features that make it more successful, then become so interwoven with other parts of the habitat (like a plant) so that in retrospect it appears neither could ever have existed without the other. But the thing with the DNA seems more circular. Could someone tell me what the cutting edge theory is? If anyone knows but doesn't want to explain it, but could give me a link to a good article, that would be awesome.

Replies to this message:
 Message 3 by Rei, posted 09-23-2004 3:18 PM Doofy has replied
 Message 4 by Loudmouth, posted 09-23-2004 3:21 PM Doofy has replied
 Message 13 by judhajeetray, posted 12-02-2004 11:00 AM Doofy has not replied

  
Doofy
Inactive Member


Message 5 of 14 (144139)
09-23-2004 3:42 PM
Reply to: Message 3 by Rei
09-23-2004 3:18 PM


Thanks, both of you. I already knew a (small) part of this. I knew that the very prototype self replicating molecules were a lot simpler. I don't know how to do the quote yet, I will figure it out later.
Rei wrote:
5. The more "like" the original protein that results from a reaction, and the wider the possible range of input materials, the more common it will become. Soon, you effectively have an effective self replicator, or more likely, a group of molecules that work together to replicate each other. This is known as a "hypercycle".
I've never heard of a "hypercycle" before. I know proteins commonly function as enzymes that catalyze reactions. So you're saying that according to this theory, a protein that formed, essentially, randomly, and then catalyzes a reaction, and the result of the reaction is to make more proteins of its "kind"--that is a hypercycle? And that would be the very very first self-replicating molecule, a protein that causes more of its "kind" to be formed? Then several of these enzymes..get together somehow? In something like a symbiotic relationship. That really does make a lot of sense. What is this theory called? Who thought it up?
I think I will check out that link and see what it says. By the way, in an astronomy class I took I did learn about the amino acids which have been found in outer space--I thought that was very cool!

This message is a reply to:
 Message 3 by Rei, posted 09-23-2004 3:18 PM Rei has replied

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Doofy
Inactive Member


Message 6 of 14 (144148)
09-23-2004 4:02 PM
Reply to: Message 4 by Loudmouth
09-23-2004 3:21 PM


Loudmouth said:
A google search can turn up more. If you want, I could do a more in depth search if you have questions on specifics.
Thank you, but that's okay. That link you gave was very good. I can find stuff on the internet, I just didn't know where to start. I have biology books, but their mention of those theories is very very uninformative. I guess one studies that stuff in molecular. I am more into organism/ecology. I have not studied molecular biology at all in college yet.

This message is a reply to:
 Message 4 by Loudmouth, posted 09-23-2004 3:21 PM Loudmouth has replied

Replies to this message:
 Message 8 by Loudmouth, posted 09-23-2004 5:27 PM Doofy has not replied
 Message 9 by AdminAsgara, posted 09-23-2004 9:31 PM Doofy has not replied

  
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