|
Register | Sign In |
|
QuickSearch
Thread ▼ Details |
Junior Member (Idle past 4620 days) Posts: 23 From: California Joined: |
|
Thread Info
|
|
|
Author | Topic: Are Point Mutations problematic for ToE? | |||||||||||||||||||||||||||
jar Member (Idle past 422 days) Posts: 34026 From: Texas!! Joined: |
I would rather call it just one of the mechanisms. It is certainly not a problem, more just one addition step towards understanding.
Anyone so limited that they can only spell a word one way is severely handicapped!
|
|||||||||||||||||||||||||||
subbie Member (Idle past 1282 days) Posts: 3509 Joined: |
Well, by definition it must be more of a confirmation since it's not a problem to any degree whatsoever.
Actually, as I think about this more, there's no need to assume homogeneity of the parent population. The only important factor is whether the mutation introduces an allele to the daughter population that wasn't present in the parent population. And, there's also one more situation where that new allele may not necessarily increase the "genetic information" in the population. That is where the mutation eliminates an allele from the population. Ridicule is the only weapon which can be used against unintelligible propositions. -- Thomas Jefferson We see monsters where science shows us windmills. -- Phat It has always struck me as odd that fundies devote so much time and effort into trying to find a naturalistic explanation for their mythical flood, while looking for magical explanations for things that actually happened. -- Dr. Adequate ...creationists have a great way to detect fraud and it doesn't take 8 or 40 years or even a scientific degree to spot the fraud--'if it disagrees with the bible then it is wrong'.... -- archaeologist
|
|||||||||||||||||||||||||||
seanfhear Junior Member (Idle past 4620 days) Posts: 23 From: California Joined: |
Would it be appropriate to assume a trait for an allele as an example and to speculate what could be a possible change in the function or structure of an organism if information was lost? Can you think of a simple example?
"Anyone who has the power to make you believe absurdities has the power to make you commit injustices." Voltaire
|
|||||||||||||||||||||||||||
Omnivorous Member Posts: 3990 From: Adirondackia Joined: Member Rating: 6.9 |
Hi, Sean, and welcome.
I'd just like to comment on your remark:
seanfhear writes: I see what you mean by a continueing loss of genetic information. Even if the process went on for a fairly short period of time I guess all you would end up with is an organism with some serious disabilities. Anglagard was pointing out the flaw in the "point mutations always mean genetic information loss" argument. When the process goes on long enough, what you have is evolution. Dost thou prate, rogue? -Cassio Real things always push back.-William James
|
|||||||||||||||||||||||||||
seanfhear Junior Member (Idle past 4620 days) Posts: 23 From: California Joined: |
Sorry. My comment was directed to anglagard’s Also if the experiment is continued for an infinite amount of time would that result in the moths eventually having no genetic information under the always loss scenario. How would they exist with no genes?
I do realize from all the authoritative information thus far that point mutations are a part of the evolutionary process. Thank you. "Anyone who has the power to make you believe absurdities has the power to make you commit injustices." Voltaire
|
|||||||||||||||||||||||||||
Coyote Member (Idle past 2134 days) Posts: 6117 Joined: |
Welcome!
Like your avatar. Very important for radiocarbon dating, which I do a lot of.
|
|||||||||||||||||||||||||||
seanfhear Junior Member (Idle past 4620 days) Posts: 23 From: California Joined: |
Thanks. It kinda goes with the name. Check it out.
"Anyone who has the power to make you believe absurdities has the power to make you commit injustices." Voltaire
|
|||||||||||||||||||||||||||
anglagard Member (Idle past 864 days) Posts: 2339 From: Socorro, New Mexico USA Joined: |
A belated welcome as well, love the sig.
The idea of the sacred is quite simply one of the most conservative notions in any culture, because it seeks to turn other ideas - uncertainty, progress, change - into crimes. Salman Rushdie This rudderless world is not shaped by vague metaphysical forces. It is not God who kills the children. Not fate that butchers them or destiny that feeds them to the dogs. It’s us. Only us. - the character Rorschach in Watchmen
|
|||||||||||||||||||||||||||
Dr Adequate Member (Idle past 312 days) Posts: 16113 Joined: |
"Point mutation" can mean one of two things. It can, as crashfrog wrote, mean the substitution of one base for another; or it can mean that or the insertion or deletion of a single base; as distinct from larger-scale mutations such as the fusion of two chromosomes.
To avoid confusion you can write "single nucleotide substitution" to mean point mutation in the first sense. The same reasoning as I presented obviously applies (with suitable amendments) to insertions and deletions as well --- an insertion is reversed by a deletion, and a deletion by an insertion.
|
|||||||||||||||||||||||||||
Percy Member Posts: 22500 From: New Hampshire Joined: Member Rating: 4.9 |
seanfhear writes: Would it be appropriate to assume a trait for an allele as an example and to speculate what could be a possible change in the function or structure of an organism if information was lost? Can you think of a simple example? One good example is vitamin C synthesis in humans. A single point mutation, in this case a deletion, caused a frame shift in the GULO gene responsible for the synthesis of vitamin C. A frame shift is what happens when a single nucleotide is inserted or deleted. A frame shift works like this. Say you have this simple nucleotide sequence that I've divided into triplets:
TAG / CAT / GCC Now let's perform a single nucleotide deletion, let's say the 2nd nucleotide gets deleted. We're now left with this:
TAC / ATG / CC The loss of a single nucleotide has caused the framing of codons to shift, hence the name frame shift mutation. TAG has become TAC, CAT has become ATG, and GCC has become an incomplete codon CC. As you can see, a single nucleotide deletion has the potential to completely change the codon sequences and thereby the protein it is responsible for. This is in essence what happened somewhere in the distant evolutionary ancestry of apes. A frame shift mutation in the GULO gene responsible for the synthesis of vitamin C experienced the deletion of a single nucleotide that resulted in a premature stop codon. In humans vitamin C synthesis never completes because of the premature stop codon. We have to get all our vitamin C from what we eat. Here's a comparison of the same subsequence of the rat and human GULO gene. To make it easier to interpret I've included the human sequence twice, once with a dash where the cytosine nucleotide was, and then again with the frame shift:
[face=Lucida Console]Rat: GTA / GAG / GTG / CGC / TTC / ACC / CGA / GGC / GAT / GAC / ATT / CTG / CTG / AGC / CCC Human: GTG / GGG / GTA / CGC / TTC / ACC / TGG / AG- / GAT / GAC / ATC / CTA / CTG / AGC / CCC (without frame shift) Human: GTG / GGG / GTA / CGC / TTC / ACC / TGG / AGG / ATG / ACA / TCC / TAC / TGA / GCC / CC (with frame shift) Single cytosine nucleotide deletion------------^[/face] Sorry it's so wide. --Percy Edited by Percy, : Reduce width by using less of the nucleotide sequence. Edited by Percy, : Typo.
|
|||||||||||||||||||||||||||
caffeine Member (Idle past 1052 days) Posts: 1800 From: Prague, Czech Republic Joined: |
I don't think this is particularly useful example since (as far as I know), there's no relevant mutating going on here. The light and dark morphs of the moth already existed in the population before northern England was turned into a grim, smog-caked wasteland. All that happened was a change in frequencies as selection favoured light, then dark, then light individuals again.
|
|||||||||||||||||||||||||||
anglagard Member (Idle past 864 days) Posts: 2339 From: Socorro, New Mexico USA Joined: |
Maybe so, maybe not - Phish
The idea of the sacred is quite simply one of the most conservative notions in any culture, because it seeks to turn other ideas - uncertainty, progress, change - into crimes. Salman Rushdie This rudderless world is not shaped by vague metaphysical forces. It is not God who kills the children. Not fate that butchers them or destiny that feeds them to the dogs. It’s us. Only us. - the character Rorschach in Watchmen
|
|||||||||||||||||||||||||||
barbara Member (Idle past 4830 days) Posts: 167 Joined: |
Let’s say there was a large population of one type of species and there was a stream running down the middle until eventually it became a wide river that separated the population in half. Wouldn’t this create a reduction in gene flow for both sides of the river? What is observed is that each population changes over time until they have little resemblance to each other and are classified under a new name. How did they obtain these new genes?
|
|||||||||||||||||||||||||||
AZPaul3 Member Posts: 8558 From: Phoenix Joined: Member Rating: 4.9 |
Mutation/Selection. Since there is no flow between the separated populations all new versions of the alleles, any mutations that survive, will exist solely within the one population in which it arose and will not reach the other side of the river. Over a few thousand generations the accumulation of differences can be enough to consider them separate species.
Edited by AZPaul3, : sub-title
|
|||||||||||||||||||||||||||
Blue Jay Member (Idle past 2725 days) Posts: 2843 From: You couldn't pronounce it with your mouthparts Joined: |
Hi, Subbie.
subbie writes: Obviously the total "genetic information" in the population will increase... I agree with you on this perspective, and I've used this argument before too. But, thinking about it now, I don't know this is really a useful argument, since, on the population scale, a mutation is essentially defined as an increase in information. Obviously, this isn't what creationists object to at all. I think, in order to get at what creationists object to, you have to show an information increase in relation to the same gene before it mutated. But, then you get all the definition problems about what counts as "more" or "less" information. The best way to deal with this mess is what Dr A and Percy did: a demonstration that the objection is invalid no matter how you define "information." The only way to defeat their argument is to imply some sort of mechanism that assesses whether a "proposed" mutation will add or subtract information, and forbids those that will add, but this idea seems stupid. -Bluejay (a.k.a. Mantis, Thylacosmilus) Darwin loves you.
|
|
|
Do Nothing Button
Copyright 2001-2023 by EvC Forum, All Rights Reserved
Version 4.2
Innovative software from Qwixotic © 2024