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Author Topic:   natural selection is wrong
biochem_geek
Inactive Junior Member


Message 255 of 276 (123742)
07-11-2004 12:35 PM
Reply to: Message 254 by redwolf
07-11-2004 10:36 AM


quote:
In real life, mutations which involve changes large enough to conceivably lead to new kinds of animals...
But no modern day biologists claim that new species result from single mutations. Such events are called saltations, and aren’t part of modern evolutionary biology. You’re throwing some pretty big accusations around, but seem to have no idea what it is your attacking.
Speciation happens due to genetic differences accruing between two populations that are isolated for sometime (for instance living on different islands) so not able to mate, and mix there genes. After some time even if the two populations were brought back together they are so different that they could not produce viable offspring so are considered different species. Here's a couple of journal abstracts about evidence for this process at a molecular level:
Abstract number 1
Abstract number 2
quote:
Ever notice that they're ALWAYS collecting money for research aimed at eliminating mutations, and not for research aimed at causing them? Think there might be a reason for that?
Obvioulsly most detectable mutations are going to be deleterious. Again no one ever claims anything over that that to be true. All that NS needs is that some mutation will lead to an organism being better adapted to its environment and as a result out compete the rest of the population and as a result generate more children with the trait. Here's a list of known, beneficial mutaations.
quote:
ther than that, the amounts of time it would take to spread ANY kinds of mutations, "beneficial" or otherwise, around our planet sufficiently to create our present biosphere has been shown to be impossible
The arguments in the website you linked to are just wilfully stupid. (for those that haven’t read it the author claims that since there are 3 billion base pairs in the human genome that it must have mutated at almost 1 bp per year since the beginning of life) He ignores the v fact that over half our genome is derived from LINE and Alu elements — mobile DNA that copies itself in the genome, thousands of bases at a time. Or that duplication of chromosomes and even whole genomes has been shown to occur. Other than that the author presents an argument from incredulity with nothing so boring as evidence or even bad calculations to get in the way of him airing his prejudices.

This message is a reply to:
 Message 254 by redwolf, posted 07-11-2004 10:36 AM redwolf has replied

Replies to this message:
 Message 257 by redwolf, posted 07-11-2004 2:17 PM biochem_geek has not replied

  
biochem_geek
Inactive Junior Member


Message 266 of 276 (123853)
07-12-2004 12:03 AM
Reply to: Message 264 by redwolf
07-11-2004 9:21 PM


Re: Here's a list of known, beneficial mutaations....
Alright, for the sake of argument here are some beneficial human mutations
The fact that these are all mutations that make a small difference to the phenotype of the organism carrying them is exactly what evolutionary biology predicts. Small changes co-evolving, to generate the sort of systems that you are talking about. No one claims that a dinosaur was one day born with wings and that was a bird. Rather something more like this probably occurred:
-Some dinosaurs developed arms that had "wing like features" - perhaps an extra flap of skin - this mutation proved beneficial for some reason, maybe because it allowed the dinosaurs that carried to cool themselves more efficiently.
-Natural selection continued to favour larger flaps ‘till one day the flap-armed dinosaurs could use these flaps to slow their decent from trees, meaning they could perhaps live high up in trees and ambush ground dwelling species. (There are snakes alive today that do almost exactly this.) At the same time animals that had randomly mutated to have slightly lighter bones or feather like scales will be favoured - because these mutations wil allow a carrier to better expolit this way of life
-From here NS could favour bigger and bigger flaps till you get something akin to the gliding mammals like flying foxes and sugar gliders.
-Finally flying as we know it is favoured as the flaps turn into true wings. All along the way other small step mutations that give rise to feathers, beaks, hollow bones and the sort of brain software required for flight are selected for.
This is a short sketch of what really happened, an of course we weren’t there so we will never no the actually details of how each step occurred. What the example hopefully does show you is that evolutionary biology doesn’t require saltations, and that the big differences that we observe between what creationists call kinds is the result of millions of years of evolutionary separation between major lineages and compounding small step mutations.

This message is a reply to:
 Message 264 by redwolf, posted 07-11-2004 9:21 PM redwolf has not replied

  
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