Understanding through Discussion


Welcome! You are not logged in. [ Login ]
EvC Forum active members: 62 (9041 total)
87 online now:
Aussie, dwise1 (2 members, 85 visitors)
Newest Member: maria
Post Volume: Total: 885,913 Year: 3,559/14,102 Month: 179/321 Week: 39/59 Day: 0/4 Hour: 0/0


Thread  Details

Email This Thread
Newer Topic | Older Topic
  
Author Topic:   Can mutation and selection increase information?
JonF
Member
Posts: 6174
Joined: 06-23-2003


Message 41 of 222 (811737)
06-11-2017 10:28 AM


An analogy is not an argument. It can be used to explain an argument. Make your argument about biological evolution then, if necessary, explain it with an analogy.

Replies to this message:
 Message 42 by RAZD, posted 06-11-2017 12:04 PM JonF has not yet responded

  
JonF
Member
Posts: 6174
Joined: 06-23-2003


Message 47 of 222 (811890)
06-13-2017 8:39 AM
Reply to: Message 46 by Vlad
06-13-2017 8:33 AM


Re: Mutations and new information
Analogy is still not argument.

This message is a reply to:
 Message 46 by Vlad, posted 06-13-2017 8:33 AM Vlad has not yet responded

  
JonF
Member
Posts: 6174
Joined: 06-23-2003


(1)
Message 79 of 222 (815972)
07-27-2017 8:53 AM
Reply to: Message 78 by CRR
07-27-2017 7:06 AM


Re: random and non-random mutations
Ah, the good ol' equivocation on "random".

Genetic changes can respond to environmental events. They are still random with respect to fitness.


This message is a reply to:
 Message 78 by CRR, posted 07-27-2017 7:06 AM CRR has responded

Replies to this message:
 Message 97 by CRR, posted 08-01-2017 3:32 AM JonF has responded

  
JonF
Member
Posts: 6174
Joined: 06-23-2003


Message 85 of 222 (815992)
07-27-2017 12:50 PM
Reply to: Message 82 by Taq
07-27-2017 11:38 AM


Re: random and non-random mutations
Probably referring to the (irrelevant) fact that in many situations environmental stress can increase mutation rates.

This message is a reply to:
 Message 82 by Taq, posted 07-27-2017 11:38 AM Taq has responded

Replies to this message:
 Message 87 by Taq, posted 07-27-2017 1:17 PM JonF has responded

  
JonF
Member
Posts: 6174
Joined: 06-23-2003


Message 88 of 222 (816007)
07-27-2017 6:53 PM
Reply to: Message 87 by Taq
07-27-2017 1:17 PM


Re: random and non-random mutations
ITYM "neutral and deleterious"?

This message is a reply to:
 Message 87 by Taq, posted 07-27-2017 1:17 PM Taq has not yet responded

  
JonF
Member
Posts: 6174
Joined: 06-23-2003


(2)
Message 100 of 222 (816233)
08-01-2017 9:22 AM
Reply to: Message 97 by CRR
08-01-2017 3:32 AM


Re: random and non-random mutations
Ah, the good ol' equivocation on "random".
Genetic changes can respond to environmental events. They are still random with respect to fitness.

There are 2 ways in which this isn't random.
First, the periods of accelerated mutation aren't random in time, they occur when required to adapt to the environment.
Second, they aren't randomly distributed throughout the genome; specific areas are targeted.
So it appears the organism is searching for solutions with a constrained solutions space to adapt to a specific challenge. Perhaps in time we will discover even this isn't entirely random.


Cool! You respond to my pointing out your equivocation with two more equivocations.

When we speak of random mutations we always mean random with respect to fitness. So your two ways in which this isn't random are true but irrelevant.

It does appear that this sort of phenomenon evolved as a response to stress. But it does not mean that the organism is searching to adapt to a specific challenge, because the effect of the mutations is not specific to the challenge. That is, random with respect to fitness.

Unlike creationists, scientists are always poking and prodding and testing. When and if someone discovers the process isn't exactly random with respect to fitness you will have an argument. But not now.


This message is a reply to:
 Message 97 by CRR, posted 08-01-2017 3:32 AM CRR has not yet responded

  
JonF
Member
Posts: 6174
Joined: 06-23-2003


Message 110 of 222 (816279)
08-02-2017 8:51 AM
Reply to: Message 108 by CRR
08-02-2017 3:59 AM


Re: random and non-random mutations
However type 2 appear to be goal directed in response to the trigger.

They do not appear to be goal directed. In some circumstances they are a response to environmental stress.

They are random with respect to fitness.

Unless, of course, you have evidence to the contrary.

No?

Didn't think so.


This message is a reply to:
 Message 108 by CRR, posted 08-02-2017 3:59 AM CRR has responded

Replies to this message:
 Message 118 by CRR, posted 08-04-2017 8:04 AM JonF has responded

  
JonF
Member
Posts: 6174
Joined: 06-23-2003


Message 120 of 222 (816425)
08-04-2017 9:41 AM
Reply to: Message 118 by CRR
08-04-2017 8:04 AM


Re: random and non-random mutations
If they occur in response to environmental stress and the increased mutation rate helps the organism to adapt to that stress then possibly it is goal directed.
The goal is to adapt to the stress.

It's possible but the evidence indicates it is not. Got any evidence it's goal directed?

The mutations we see in response to stress are the same as the mutations we see without stress, just more of them. If the organism is lucky one of them might adapt to the stress. The organism has to be very very lucky. Most organisms won't get an adaptational mutation. BUt a slim chance is better than no chance.

It's a reasonable hypothesis based on the observations, and should not be excluded at this stage.

List the observations and explain why the support your claim, please.

The vast majority of mutations are detrimental, probably including those that code for the same amino acid.

The vast majority of mutations are neutral. What evidence do you have "those that code for the same amino acid" are detrimental?

There is some evidence that even where the mutation codes for the same amino acid it can affect other things such as the rate of production.

Evidence please?

And what does that have to do with the fact that responses to stress are random with respect to fitness?


This message is a reply to:
 Message 118 by CRR, posted 08-04-2017 8:04 AM CRR has not yet responded

  
JonF
Member
Posts: 6174
Joined: 06-23-2003


Message 125 of 222 (816481)
08-05-2017 8:24 AM
Reply to: Message 122 by CRR
08-04-2017 8:47 PM


Re: random and non-random mutations
You can have a search that is both goal directed and random.

Yes. So what? We have plenty of evidence that the processes that increases mutation rate are not goal seeking. Naming wildly different processes doesn't affect that.

Similarly

Not at all similarly. Analogies are not evidence. The two processes are totally disssimilar.

when mutations increase in selected regions in response to an environmental stress there is a good chance that the goal is to adapt to the stressor

Not according to the evidence we have.

Got any evidence for your claim?

Didn't think so.

This is a hypothesis. There is insufficient evidence at this time to accept it, but there is even less evidence to reject it.

What evidence have you studied to conclude that there is less evidence to reject it than for it?

[multiple citations required]

I'll start. Mutation as a Stress Response and the Regulation of Evolvability:

quote:
Our concept of a stable genome is evolving to one in which genomes are plastic and responsive to environmental changes. Growing evidence shows that a variety of environmental stresses induce genomic instability in bacteria, yeast, and human cancer cells, generating occasional fitter mutants and potentially accelerating adaptive evolution. The emerging molecular mechanisms of stress-induced mutagenesis vary but share telling common components that underscore two common themes. The first is the regulation of mutagenesis in time by cellular stress responses, which promote random* mutations specifically when cells are poorly adapted to their environments, i.e., when they are stressed. A second theme is the possible restriction of random* mutagenesis in genomic space, achieved via coupling of mutation-generating machinery to local events such as DNA-break repair or transcription. Such localization may minimize accumulation of deleterious mutations in the genomes of rare fitter mutants, and promote local concerted evolution. Although mutagenesis induced by stresses other than direct damage to DNA was previously controversial, evidence for the existence of various stress-induced mutagenesis programs is now overwhelming and widespread. Such mechanisms probably fuel evolution of microbial pathogenesis and antibiotic-resistance, and tumor progression and chemotherapy resistance, all of which occur under stress, driven by mutations. The emerging commonalities in stress-induced-mutation mechanisms provide hope for new therapeutic interventions for all of these processes.

{emphaisi added}

*Remember that to biologists studying mutations "random" means "randiom with respect to fitness".

Edited by JonF, : No reason given.

Edited by JonF, : Fix bolding


This message is a reply to:
 Message 122 by CRR, posted 08-04-2017 8:47 PM CRR has responded

Replies to this message:
 Message 127 by RAZD, posted 08-05-2017 12:00 PM JonF has not yet responded
 Message 130 by CRR, posted 08-10-2017 2:19 AM JonF has not yet responded

  
JonF
Member
Posts: 6174
Joined: 06-23-2003


Message 132 of 222 (816734)
08-10-2017 8:29 AM
Reply to: Message 129 by CRR
08-10-2017 2:17 AM


Re: random and non-random mutations
IOW it's a story you made up, you like, and is contradicted by the evidence.

I have no other evidence to support or refute that hypothesis at this time

This is a hypothesis. There is insufficient evidence at this time to accept it, but there is even less evidence to reject it.

Make up your mind.


This message is a reply to:
 Message 129 by CRR, posted 08-10-2017 2:17 AM CRR has not yet responded

  
JonF
Member
Posts: 6174
Joined: 06-23-2003


Message 137 of 222 (816826)
08-11-2017 6:08 PM
Reply to: Message 136 by CRR
08-11-2017 6:03 PM


Re: random and non-random mutations
Still nothing to do with the fact that the mutations are random with respect to fitness.

You need evidence, not analogies.

You admitted you have none.

You have failed.

When, you've dug yourself into a hole, what should you do?


This message is a reply to:
 Message 136 by CRR, posted 08-11-2017 6:03 PM CRR has not yet responded

  
JonF
Member
Posts: 6174
Joined: 06-23-2003


Message 140 of 222 (816903)
08-13-2017 8:23 AM
Reply to: Message 139 by CRR
08-13-2017 2:01 AM


Re: random and non-random mutations
The issue is with the word "directed".

quote:
1. guided, regulated, or managed:a carefully directed program.
2. subject to direction, guidance, regulation, etc.

All the evidence we have is there is nothing guiding, regulating, or managing the mutations we are discussing.

Got any evidence for your position?


This message is a reply to:
 Message 139 by CRR, posted 08-13-2017 2:01 AM CRR has responded

Replies to this message:
 Message 141 by CRR, posted 08-13-2017 7:21 PM JonF has responded

  
JonF
Member
Posts: 6174
Joined: 06-23-2003


(1)
Message 142 of 222 (816934)
08-13-2017 7:44 PM
Reply to: Message 141 by CRR
08-13-2017 7:21 PM


Re: random and non-random mutations
The subject is not the universe of possible searches. The subject is a particular "search" (not everyone thinks it is a search).

Mutation rate can increase under stress. Do you have any evidence those mutations are not random with respect to fitness?

{Rhetorical question. You have admitted you don't. So all this current blathering is off topic and pointless.)


This message is a reply to:
 Message 141 by CRR, posted 08-13-2017 7:21 PM CRR has not yet responded

  
JonF
Member
Posts: 6174
Joined: 06-23-2003


Message 148 of 222 (817349)
08-16-2017 7:42 PM
Reply to: Message 147 by CRR
08-16-2017 6:51 PM


Re: random and non-random mutations
It doesn't matter what any "random" search may or may not be. We are discussing one particular "search". You have admitted you have no evidence that particular "search" is related to a goal in any way.

Blathering on about anything other than that particular "search" is pointless. Please address the subject.


This message is a reply to:
 Message 147 by CRR, posted 08-16-2017 6:51 PM CRR has responded

Replies to this message:
 Message 149 by CRR, posted 08-16-2017 9:36 PM JonF has responded

  
JonF
Member
Posts: 6174
Joined: 06-23-2003


Message 150 of 222 (817370)
08-17-2017 8:45 AM
Reply to: Message 149 by CRR
08-16-2017 9:36 PM


Re: random and non-random mutations
You have admitted you have no evidence that particular "search" is related to a goal in any way.

Incorrect.

O rly?

Similarly when mutations increase in selected regions in response to an environmental stress there is a good chance that the goal is to adapt to the stressor, even if the mutations are essentially random. Since the hypermutation targets certain areas it is likely these areas have a higher probability of producing a favourable mutation. Conversely hypermutation in other areas of the genome are less likely to produce a mutation favourable to adaptation.

This is a hypothesis. There is insufficient evidence at this time to accept it, but there is even less evidence to reject it.

{Of course there is lots of evidence to reject it; ignoring it doesn't make that go away).

It appears this is a mechanism to adapt to the event and that makes it goal-directed; the goal being to adapt.

For which there is absolutely no evidence. I already posted one paper demonstrating your hypothesis is false; how many more shall I post?

At this stage I don't think there is specific evidence either way.

Another admission of having no evidence for your claim.


This message is a reply to:
 Message 149 by CRR, posted 08-16-2017 9:36 PM CRR has not yet responded

  
Newer Topic | Older Topic
Jump to:


Copyright 2001-2018 by EvC Forum, All Rights Reserved

™ Version 4.0 Beta
Innovative software from Qwixotic © 2021