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Author Topic:   How do you define the word Evolution?
Dr Adequate
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Posts: 15963
Joined: 07-20-2006
Member Rating: 4.9


Message 301 of 936 (805513)
04-19-2017 2:19 AM
Reply to: Message 298 by Dredge
04-19-2017 2:01 AM


The only way to stop creationists like me claiming to be evolutionists is to include the theory that all life evolved from a single-cell-like organism in the defintion of evolution.

I am unable to change the definitions of scientific terms; and I am fairly indifferent if you want to make obviously false claims about yourself. For all I care you can claim to be a chocolate-coated revolving umbrella stand.


This message is a reply to:
 Message 298 by Dredge, posted 04-19-2017 2:01 AM Dredge has not yet responded

  
Dredge
Member
Posts: 605
From: Australia
Joined: 09-06-2016
Member Rating: 1.4


Message 302 of 936 (805517)
04-19-2017 2:57 AM
Reply to: Message 300 by Dr Adequate
04-19-2017 2:17 AM


Re: If Not, What?
If the antibiotic came first, this means the mutation that confers immunity wasn't present in the original population. So how did any bacteria survive the antibiotic if none of them had the immunity mutation?
This message is a reply to:
 Message 300 by Dr Adequate, posted 04-19-2017 2:17 AM Dr Adequate has responded

Replies to this message:
 Message 304 by Dr Adequate, posted 04-19-2017 3:09 AM Dredge has responded

    
Dredge
Member
Posts: 605
From: Australia
Joined: 09-06-2016
Member Rating: 1.4


Message 303 of 936 (805518)
04-19-2017 3:01 AM
Reply to: Message 284 by Dr Adequate
04-17-2017 9:51 PM


Dr. Adequate: "You are not an evolutionist."

Why am I not an evolutionist? What is your definition of an evolutionist?

Edited by Dredge, : No reason given.


This message is a reply to:
 Message 284 by Dr Adequate, posted 04-17-2017 9:51 PM Dr Adequate has responded

Replies to this message:
 Message 305 by Dr Adequate, posted 04-19-2017 3:19 AM Dredge has not yet responded

    
Dr Adequate
Member
Posts: 15963
Joined: 07-20-2006
Member Rating: 4.9


Message 304 of 936 (805519)
04-19-2017 3:09 AM
Reply to: Message 302 by Dredge
04-19-2017 2:57 AM


Re: If Not, What?
If the antibiotic came first, this means the mutation that confers immunity wasn't present in the original population. So how did any bacteria survive the antibiotic if none of them had the immunity mutation?

The effect of an antibiotic depends on its concentration: a concentration which is not universally lethal will still inhibit growth and reproduction, which acts as a selective pressure in favor of mutations conferring immunity.


This message is a reply to:
 Message 302 by Dredge, posted 04-19-2017 2:57 AM Dredge has responded

Replies to this message:
 Message 363 by Dredge, posted 04-20-2017 10:39 PM Dr Adequate has responded

  
Dr Adequate
Member
Posts: 15963
Joined: 07-20-2006
Member Rating: 4.9


(2)
Message 305 of 936 (805520)
04-19-2017 3:19 AM
Reply to: Message 303 by Dredge
04-19-2017 3:01 AM


Why am I not an evolutionist?

Who knows? Perhaps you were dropped on your head as a child.

What is your definition of an evolutionist?

One who adheres to evolutionary explanations for the diversity of life.


This message is a reply to:
 Message 303 by Dredge, posted 04-19-2017 3:01 AM Dredge has not yet responded

  
CRR
Member
Posts: 578
From: Australia
Joined: 10-19-2016
Member Rating: 1.1


Message 306 of 936 (805551)
04-19-2017 8:50 AM
Reply to: Message 292 by Dr Adequate
04-18-2017 12:22 AM


Re: If Not, What?
Let us consider a not uncommon evolutionary event. A population of bacteria is exposed to an antibiotic. A mutation arises conferring immunity.

Actually this is an uncommon event. Frozen samples retrieved from the remains of the Franklin Expedition showed a small proportion of antibiotic resistant members. This probably IS a mutation but it exists before the bacteria is exposed to antibiotics. The reason it is at such low levels initially is that it is a defect that is detrimental and only gives a net benefit when exposed to antibiotics.

Similar results have been found from other samples from before we started using antibiotics in medicine.

The antibiotics cause a strong negative selection against the dominant non-resistant members allowing the resistant members to rapidly increase in numbers. This is one reason that antibiotic resistance can arise within a few years; as has happened historically; the resistance was already there.


This message is a reply to:
 Message 292 by Dr Adequate, posted 04-18-2017 12:22 AM Dr Adequate has responded

Replies to this message:
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Pressie
Member
Posts: 1809
From: Pretoria, SA
Joined: 06-18-2010
Member Rating: 2.3


Message 307 of 936 (805555)
04-19-2017 9:13 AM
Reply to: Message 306 by CRR
04-19-2017 8:50 AM


Re: If Not, What?
This one was really, really funny.

CRR writes:

Actually this is an uncommon event. Frozen samples retrieved from the remains of the Franklin Expedition showed a small proportion of antibiotic resistant members. This probably IS a mutation but it exists before the bacteria is exposed to antibiotics. The reason it is at such low levels initially is that it is a defect that is detrimental and only gives a net benefit when exposed to antibiotics.

Similar results have been found from other samples from before we started using antibiotics in medicine.

The antibiotics cause a strong negative selection against the dominant non-resistant members allowing the resistant members to rapidly increase in numbers. This is one reason that antibiotic resistance can arise within a few years; as has happened historically; the resistance was already there.

Well, the "already there resistance" didn't help those 20 million people people who died as a result of the Great Flu...

Edited by Pressie, : No reason given.

Edited by Pressie, : No reason given.


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 Message 306 by CRR, posted 04-19-2017 8:50 AM CRR has not yet responded

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Dr Adequate
Member
Posts: 15963
Joined: 07-20-2006
Member Rating: 4.9


Message 308 of 936 (805567)
04-19-2017 9:47 AM
Reply to: Message 306 by CRR
04-19-2017 8:50 AM


Re: If Not, What?
Actually this is an uncommon event. Frozen samples retrieved from the remains of the Franklin Expedition showed a small proportion of antibiotic resistant members. This probably IS a mutation but it exists before the bacteria is exposed to antibiotics. The reason it is at such low levels initially is that it is a defect that is detrimental and only gives a net benefit when exposed to antibiotics.

Your reasoning is unclear. I said that both can happen: the fact that one has happened on at least one occasion does not mean that the other one is uncommon.

If I told you that people can be either male or female, and that it was not uncommon for them to be male, would you try to refute me by triumphantly producing a single example of a woman?

Edited by Dr Adequate, : No reason given.

Edited by Dr Adequate, : No reason given.


This message is a reply to:
 Message 306 by CRR, posted 04-19-2017 8:50 AM CRR has not yet responded

  
Dr Adequate
Member
Posts: 15963
Joined: 07-20-2006
Member Rating: 4.9


Message 309 of 936 (805568)
04-19-2017 9:49 AM
Reply to: Message 307 by Pressie
04-19-2017 9:13 AM


Re: If Not, What?
Well, the "already there resistance" didn't help those 20 million people people who died as a result of the Great Flu...

I don't see your point.


This message is a reply to:
 Message 307 by Pressie, posted 04-19-2017 9:13 AM Pressie has not yet responded

  
Dr Adequate
Member
Posts: 15963
Joined: 07-20-2006
Member Rating: 4.9


Message 310 of 936 (805595)
04-19-2017 1:05 PM
Reply to: Message 297 by Faith
04-18-2017 11:34 PM


Re: alleles/mutations?
But in reality over time the neutral ones would most likely become deleterious.

How? What does this mean?

Four for a gene should be all it takes to provide all the variety we see for any given trait ...

I have given you examples about the coat color and markings of dogs where this is not the case.


This message is a reply to:
 Message 297 by Faith, posted 04-18-2017 11:34 PM Faith has responded

Replies to this message:
 Message 311 by Faith, posted 04-19-2017 1:42 PM Dr Adequate has responded

  
Faith
Member
Posts: 26455
From: Nevada, USA
Joined: 10-06-2001
Member Rating: 1.1


Message 311 of 936 (805598)
04-19-2017 1:42 PM
Reply to: Message 310 by Dr Adequate
04-19-2017 1:05 PM


Re: alleles/mutations?
But in reality over time the neutral ones would most likely become deleterious.

How? What does this mean?

Any gene that has collected a huge number of "alleles," most of which of course don't do anything, is one of those parts of the genetic code that is especially prone to mutations. So such mutated "alleles" that get passed on are going to easily accumulate more mutations until finally they do something decidedly unbeneficial to the host. It's inevitable since mutations are inherently destructive.

Four for a gene should be all it takes to provide all the variety we see for any given trait ...

I have given you examples about the coat color and markings of dogs where this is not the case.

Perhaps I didn't see it or thought it too silly to bother with. Your job is to repeat your case. abe: And by the way, there are exceptions to most rules [/abe]

Edited by Faith, : No reason given.

Edited by Faith, : No reason given.


This message is a reply to:
 Message 310 by Dr Adequate, posted 04-19-2017 1:05 PM Dr Adequate has responded

Replies to this message:
 Message 312 by PaulK, posted 04-19-2017 2:06 PM Faith has responded
 Message 316 by Dr Adequate, posted 04-19-2017 2:59 PM Faith has responded

    
PaulK
Member
Posts: 13233
Joined: 01-10-2003
Member Rating: 1.9


Message 312 of 936 (805599)
04-19-2017 2:06 PM
Reply to: Message 311 by Faith
04-19-2017 1:42 PM


Re: alleles/mutations?
quote:

Any gene that has collected a huge number of "alleles," most of which of course don't do anything, is one of those parts of the genetic code that is especially prone to mutations. So such mutated "alleles" that get passed on are going to easily accumulate more mutations until finally they do something decidedly unbeneficial to the host. It's inevitable since mutations are inherently destructive.

If there are a lot of variations it is more to do with selection than mutation rate. Which suggests that the gene tolerates quite a lot of variation - or even that variation may be beneficial. The most variable genes seem to be related to the immune system - and I can certainly see reasons why variation might be beneficial there (the weakness of a monoculture should be well known)


This message is a reply to:
 Message 311 by Faith, posted 04-19-2017 1:42 PM Faith has responded

Replies to this message:
 Message 313 by Faith, posted 04-19-2017 2:16 PM PaulK has responded

    
Faith
Member
Posts: 26455
From: Nevada, USA
Joined: 10-06-2001
Member Rating: 1.1


Message 313 of 936 (805601)
04-19-2017 2:16 PM
Reply to: Message 312 by PaulK
04-19-2017 2:06 PM


Re: alleles/mutations?
Are you talking about variations in the function of the gene or in the sequences of its many alleles? I'm talking about the latter, and I'm supposing that those alleles are just the usual useless mutations, everything from "neutral" or having no effect on the function of the gene, to destructive. I'm further supposing that a gene only has those four natural alternatives or alleles that would have been possessed by Adam and Eve or any two individuals. So, taking this into account, what are you saying again?

abe: If the most "variable" genes are those that have to do with the immune system, rather than suggesting anything beneficial, it doesn't bode well for us. And we do seem to be prone to more and more immune deficiency diseases. A friend of mine died two years ago from a sudden onset of such a disease; he'd been quite healthy sand suddenly experienced severe muscular deterioration from such a disease I forget the name of. It was six months from its onset to his death.

Edited by Faith, : No reason given.

Edited by Faith, : No reason given.

Edited by Faith, : No reason given.

Edited by Faith, : No reason given.


This message is a reply to:
 Message 312 by PaulK, posted 04-19-2017 2:06 PM PaulK has responded

Replies to this message:
 Message 314 by PaulK, posted 04-19-2017 2:28 PM Faith has responded

    
PaulK
Member
Posts: 13233
Joined: 01-10-2003
Member Rating: 1.9


(1)
Message 314 of 936 (805602)
04-19-2017 2:28 PM
Reply to: Message 313 by Faith
04-19-2017 2:16 PM


Re: alleles/mutations?
quote:

Are you talking about variations in the function of the gene or in the sequences of its many alleles?

Not every sequence variation gets counted as an allele, you know. If you want to count those you'd have even more variety to explain.

quote:

...and I'm supposing that those alleles are just the usual useless mutations, everything from "neutral" or having no effect on the function of the gene, or destructive

"Destructive" variations are only likely where the function of the gene - or rather the protein it codes for - is detrimental. Again, selection is a major factor in what we see.

quote:

I'm further supposing that a gene only has those four natural alternatives or alleles that would have been possessed by Adam and Eve or any two individuals.

Making false assumptions will tend to lead you to false conclusions, although I don't think this one matters greatly apart from prejudicing your thinking.

Anyway, I am saying that your point is wrong. Genes which gave a lot of variants must tolerate variation well - or selection would reduce the number of variants. And there are even genes where it is likely beneficial to the species to have many variants.

So genes with many variations are less likely to be "harmed" by mutation.

However your original point as stated was even worse. An existing allele can only become harmful through environmental changes, and there is no way to say that environmental changes are particularly likely to target genes with many alleles (and no way to say that they would be more harmful to later variations than to a presumed original)


This message is a reply to:
 Message 313 by Faith, posted 04-19-2017 2:16 PM Faith has responded

Replies to this message:
 Message 315 by Faith, posted 04-19-2017 2:41 PM PaulK has responded

    
Faith
Member
Posts: 26455
From: Nevada, USA
Joined: 10-06-2001
Member Rating: 1.1


Message 315 of 936 (805603)
04-19-2017 2:41 PM
Reply to: Message 314 by PaulK
04-19-2017 2:28 PM


Re: alleles/mutations?
Anyway, I am saying that your point is wrong. Genes which gave a lot of variants must tolerate variation well - or selection would reduce the number of variants.

Not if they are predominantly the "neutral" kind that are unaffected by selection. They'll just stay in the system without effect until more changes accumulate to become destructive.

And there are even genes where it is likely beneficial to the species to have many variants.

Such as? If the "many variants" are neutral differences in the DNA sequence, that don't affect the function of the protein, they aren't going to be beneficial OR destructive. But if a mutation is destructive in itself, then such changes in the sequence are likely to be ticking time bombs that can become destructive as they continue to accumulate mutations. If they kill the host then they'll be selected out, yes, but since we're all accumulating lots of these mutations, an accumulation of such destructive effects is to be expected.

So genes with many variations are less likely to be "harmed" by mutation.

You keep using that term "variations" in a vague way. If a gene can only have four naturally occurring variations, all the different "alleles" that have a neutral effect would be ticking time bombs as I say above, prone to accumulate more mutations until finally they threaten the organism. And get selected out, but meanwhile lots more of those are accumulating.

However your original point as stated was even worse. An existing allele can only become harmful through environmental changes,

This is an overworked assumption that is no doubt not true where it counts: most genetic diseases are going to get you no matter what your "environment." It's all in the changes to the gene itself, not the environment. There's no way an immune-deficiency muscle wasting disease could possibly be beneficial no matter what the environment.

and there is no way to say that environmental changes are particularly likely to target genes with many alleles

Quite true but as I said in most cases the disease is in the allele itself and not in the environment.

(and no way to say that they would be more harmful to later variations than to a presumed original)

The "later changes" represent an accumulation of mutations that increases the chance of producing a disease, quite apart from the environment.

Edited by Faith, : No reason given.


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Replies to this message:
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