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Author Topic:   Will mutations become less freqent?
Elliot
Inactive Member


Message 1 of 25 (332243)
07-16-2006 4:41 PM


After some thought, I was wondering if genetic mutations will be less frequent.
DNA is transcribed and transcripted via several enzymes (including DNA replicase, helicase etc), and this is when the mutations occur. Well what if there was a mutation in the DNA, and one or more of those enzymes were more accurate when copying or transcribing DNA - there would be less random mutations. This new DNA would be more favourable, as long as the environment was stable and devoid of major changes, as it would be copied more accurately compared to other DNA strands in other animals.
This would continue, and the enzymes becoming more accurate (other factors other than enzymes can be considered, e.g. the solution in the nuclear envelope, but I'll just stick to enzymes) until the probability of mutation is incredibly small.
This also offers a small explaination to the dinosaurs, because if they had less DNA mutations then they would be less likely to survive a major climate change.

Replies to this message:
 Message 3 by crashfrog, posted 07-16-2006 9:00 PM Elliot has not replied
 Message 5 by PaulK, posted 07-17-2006 2:39 AM Elliot has replied
 Message 9 by Scaryfish, posted 07-20-2006 11:10 PM Elliot has not replied
 Message 25 by mick, posted 08-14-2006 3:09 AM Elliot has not replied

  
Elliot
Inactive Member


Message 6 of 25 (333289)
07-19-2006 11:56 AM
Reply to: Message 5 by PaulK
07-17-2006 2:39 AM


I was still theorising in a stable environment, which is entirely possible. If the environment was changing then this new DNA would be wiped out very quickly.
Also have you never heard of convergent evolution? If the dinosaurs had a steady environment then they would have less need for mutations.

This message is a reply to:
 Message 5 by PaulK, posted 07-17-2006 2:39 AM PaulK has replied

Replies to this message:
 Message 7 by PaulK, posted 07-19-2006 12:04 PM Elliot has replied
 Message 10 by RAZD, posted 07-21-2006 10:06 PM Elliot has replied

  
Elliot
Inactive Member


Message 8 of 25 (333311)
07-19-2006 12:18 PM
Reply to: Message 7 by PaulK
07-19-2006 12:04 PM


Well the stability of the environment would differ depending on the habitat of the species. So land and sea animals may have got the worst of the meteor (if there was one).
The age of the species and the stability of the environment will also determine how accurate their DNA transcription and translation is.
Also referring to the weak anthropic principal (best argument of them all ), the reason we only see the bird and mammals, and no dinosaurs (yet lol) nowadays is because they were the only ones to survive.

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Elliot
Inactive Member


Message 11 of 25 (334203)
07-22-2006 4:40 AM
Reply to: Message 10 by RAZD
07-21-2006 10:06 PM


I am talking about convergent evolution that some (or all) species could evolve more accurate condititions for DNA replication and transcription. (Not into one species )
When I mean stable, I don't mean rapidly changine. You can still have animals that don't evolve, yet cope well with seasons, it's not like their DNA spontaneously mutates when it comes to winter.
Climate variations in some areas are stable (e.g. islands where the water around stabilises the temperature.
Techtonic effects don't happen everywhere, some land masses don't even lie on any techtonic boundary. And the predator-prey relation ship maintains itself generally, if you look at graphs mapping time against number of animals, the predator and prey line fluctuate, with the predator line being slightly after.
Overall I am saying that in an environment which is not rapidly changing, species would evolve more accurate means of copying DNA. This would then propagate around the DNA pool, as there would be more copys of it and less mutation when copying. Think of this as "I it works, don't fix it", as if the animal is doing well and there is little need to change, it is guarding against bad mutations (such as sickle cell aenema and other ,especially resessive, genetic diseases) which could theaten the population.
Also remember that you do have variation in the population, and natural selection would continue evolution.
If the environment was changing, then this would be a disadvantage, having lower mutations, as there would be a lower probability that an animal will have a unique adaptation allowing it to survive and propagate that gene.

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Replies to this message:
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 Message 13 by NosyNed, posted 07-22-2006 11:13 AM Elliot has not replied

  
Elliot
Inactive Member


Message 14 of 25 (334268)
07-22-2006 11:43 AM


Stable environment do exist.
Take some fossils for example, some species which we have fossils for that still exist, their skeletal structure remains similar, these are millions of years apart, and as they have little need to change, they don't.
And if their current form is working just fine, then the risk of a bad mutation would outweigh the benefits of a good one, so the DNA process (rightly said - IF it can be improved) would be more accurate.
The birth rate would not need to increase, a species does NOT have to evolve further, chances are it will, but it does not have to.

Replies to this message:
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