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Author Topic:   Does the history of life require "macroevolution"?
Faith
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From: Nevada, USA
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Message 46 of 126 (812316)
06-16-2017 12:02 AM
Reply to: Message 39 by Taq
06-15-2017 10:46 AM


Re: Simple Example
And I keep showing how that argument is refuted by the fact that mutations increase genetic diversity.

And, overlooking the problem that most mutations do nothing of the sort, I keep answering that to get a new species you have to eliminate (select out) most of the genetic diversity, even in extreme cases to the point of genetic depletion from which further evolution is impossible. If you want to add a mutation at that point, I'd point out that no mutations have come along in the case of the cheetah. And all you can get in any case is a variation on a trait, a new fur color perhaps, nothing structural, nothing that changes the basic characteristics of the animal. You can get all colors and sizes of just about anything but you can't get a cat to be anything but a cat, there's something about the cat genome that makes it a cat no matter how many variations of catness you can get out of it. Isn't there a part of the genome that determines basic structure?

ABE: I suspect that by genetic engineering you might be able to get a dinosaur from a lizard by exploiting genes for size of the creature and of various parts, and tweaking various functions of the lizard, but I'm quite sure you could never get a mammal that way. There's something about the genome that is so species-specific it can't change but I never hear this discussed.

Edited by Faith, : No reason given.


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 Message 39 by Taq, posted 06-15-2017 10:46 AM Taq has responded

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Taq
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Posts: 6827
Joined: 03-06-2009
Member Rating: 3.9


(1)
Message 47 of 126 (812469)
06-16-2017 5:05 PM
Reply to: Message 46 by Faith
06-16-2017 12:02 AM


Re: Simple Example
Faith writes:

And, overlooking the problem that most mutations do nothing of the sort, I keep answering that to get a new species you have to eliminate (select out) most of the genetic diversity,

That genetic diversity is then replenished with new mutations. Mutations never stop, even after a specific allele in a specific gene has reached fixation. When that gene reaches fixation then new alleles will arise from that fixed allele. It never stops.

I'd point out that no mutations have come along in the case of the cheetah.

Since when? Show me a paper that compares cheetah genomes or family triads and shows that there is not a single mutation that separates those genomes.

And all you can get in any case is a variation on a trait, a new fur color perhaps, nothing structural, nothing that changes the basic characteristics of the animal.

So you are saying that the differences between a chimp and a human has nothing to do with structure or basic characteristics?

there's something about the cat genome that makes it a cat no matter how many variations of catness you can get out of it.

Chimps and humans are variations of primates.
Bears and humans are variations of mammals.
Fish and humans are variations of vertebrates.
Trees and humans are variations of eukaryotes.

None of this is macroevolution simply because I can call them the same name? Is that what this all comes down to, the ability to call two species by the same name?

ABE: I suspect that by genetic engineering you might be able to get a dinosaur from a lizard by exploiting genes for size of the creature and of various parts, and tweaking various functions of the lizard, but I'm quite sure you could never get a mammal that way. There's something about the genome that is so species-specific it can't change but I never hear this discussed.

If we took a lizard genome and changed it so it was identical to a human genome, this wouldn't produce a human?


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Taq
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Posts: 6827
Joined: 03-06-2009
Member Rating: 3.9


Message 48 of 126 (812470)
06-16-2017 5:08 PM
Reply to: Message 45 by Faith
06-15-2017 11:38 PM


Re: Simple Example
Faith writes:

I think you said that the wrong way around. I don't think the diversity between species has anything to do with genetic inheritance so there is no genetic provision that could account for it.

If you can't account for all biodiversity with just two alleles per gene, then mutations are relevant to the discussion. You have to change the DNA sequence in order to get the biodiversity we see today.

But within a species two-allele genes/ many genes per trait, is definitely enough to account for all the enormous diversity we see.

You have yet to prove this assertion. It is just your faith based belief.

Name the trait, multiple genes with two alleles each will cover all the diversity.

The trait is HLA-A molecules on macrophages. Please show me that there are only two alleles for this gene.


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 Message 45 by Faith, posted 06-15-2017 11:38 PM Faith has responded

Replies to this message:
 Message 49 by Faith, posted 06-16-2017 7:18 PM Taq has responded

  
Faith
Member
Posts: 25606
From: Nevada, USA
Joined: 10-06-2001
Member Rating: 1.0


Message 49 of 126 (812479)
06-16-2017 7:18 PM
Reply to: Message 48 by Taq
06-16-2017 5:08 PM


Re: Simple Example
All diversity within a kind CAN be accounted for as I said. No problem whatever. I'll try to illustrate it when I can but it's not rocket science, you should be able to see it yourself. Extra alleles for some genes do not change what I've said.
This message is a reply to:
 Message 48 by Taq, posted 06-16-2017 5:08 PM Taq has responded

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Taq
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Posts: 6827
Joined: 03-06-2009
Member Rating: 3.9


Message 50 of 126 (812681)
06-19-2017 12:31 PM
Reply to: Message 49 by Faith
06-16-2017 7:18 PM


Re: Simple Example
Faith writes:

All diversity within a kind CAN be accounted for as I said. No problem whatever.

Then prove it. Show me that there are only two HLA-A alleles in the human population.


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CRR
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Posts: 450
From: Australia
Joined: 10-19-2016
Member Rating: 1.3


Message 51 of 126 (814983)
07-14-2017 8:05 AM
Reply to: Message 46 by Faith
06-16-2017 12:02 AM


Re: Simple Example
Coming in a bit late here.

Mutations can increase genetic diversity without increasing information.
E.g. If there is a point substitution such that the codon produces the same amino acid there would be a new allele but no change in produced protein or in the phenotype. It could even change the amino acid without changing the function of the protein.

A mutation can also change a function without it increasing information, such as in the sickle cell trait. This produces defective red blood cells but also provides some protection against malaria. A defect in the MC1R gene results in red hair.

The original kinds from the ark could have had up to 4 alleles for each gene, more for the clean kinds. Mutations could have increased alleles and diversity without increasing information.


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RAZD
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Posts: 18805
From: the other end of the sidewalk
Joined: 03-14-2004
Member Rating: 3.8


(1)
Message 52 of 126 (814985)
07-14-2017 8:14 AM
Reply to: Message 51 by CRR
07-14-2017 8:05 AM


Re: Simple Example
Mutations can increase genetic diversity without increasing information.
E.g. If there is a point substitution such that the codon produces the same amino acid there would be a new allele but no change in produced protein or in the phenotype. It could even change the amino acid without changing the function of the protein.

A mutation can also change a function without it increasing information, such as in the sickle cell trait. This produces defective red blood cells but also provides some protection against malaria. A defect in the MC1R gene results in red hair.

The original kinds from the ark could have had up to 4 alleles for each gene, more for the clean kinds. Mutations could have increased alleles and diversity without increasing information.

Therefore "information" is useless as a parameter for studying evolution or for predicting what can and cannot evolve.

Thanks for clarifying that.

Enjoy


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Taq
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Posts: 6827
Joined: 03-06-2009
Member Rating: 3.9


(1)
Message 53 of 126 (814991)
07-14-2017 10:58 AM
Reply to: Message 51 by CRR
07-14-2017 8:05 AM


Re: Simple Example
CRR writes:

Coming in a bit late here.
Mutations can increase genetic diversity without increasing information.
E.g. If there is a point substitution such that the codon produces the same amino acid there would be a new allele but no change in produced protein or in the phenotype. It could even change the amino acid without changing the function of the protein.

A mutation can also change a function without it increasing information, such as in the sickle cell trait. This produces defective red blood cells but also provides some protection against malaria. A defect in the MC1R gene results in red hair.

The original kinds from the ark could have had up to 4 alleles for each gene, more for the clean kinds. Mutations could have increased alleles and diversity without increasing information.

Evolution doesn't need to produce new information, as you define it, in order to produce the biodiversity we see today from a common ancestor.


This message is a reply to:
 Message 51 by CRR, posted 07-14-2017 8:05 AM CRR has responded

Replies to this message:
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Dr Jack
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Posts: 3504
From: Leicester, England
Joined: 07-14-2003


(3)
Message 54 of 126 (815003)
07-14-2017 11:55 AM
Reply to: Message 4 by Faith
06-13-2017 10:36 AM


Genes are more complex than that
All the mutations you refer to occur at a particular gene for a particular trait so all they can do is vary that trait. If it's rabbit fur color assuming they can produce something new it will be just another fur color. If it's the immune system it will supposedly provide a new protection against a new disease. In other words all such changes occur within the genome, which is the same thing as saying "within the Kind."

But this is untrue. There are not, in fact, genes for "fur colour". If we limit ourselves to the protein coding section of the genome, for simplicity, each gene codes for a protein, and these proteins are enzymes that catalyse particular chemical interactions. So the gene that impacts fur colour does it not by choosing a fur colour but by either altering the pattern of expression or action of other genes, or by catalysing the production of a particular step in a metabolic pathway that leads to the production of a pigment in the hair folicles.

Any change to the protein may produce a different pigment, it may stop functioning at all, or it may produce a substance that does something different. Whatever it does it will alter the chemical pathways of metabolism and may easily produce other effects elsewhere in the animal (few genes actually have a single effect. The multiple impacts of genes are called 'pleiotropy' or 'pleiotropic effects'.

So, in fact, "fur colour" are not simply "fur colour" genes but likely to have other impacts on the organism which are also subject to evolutionary effects and, when they change, they need not remain "fur colour" genes. The same is true for any gene classified by function. Genes operate at a biochemical level where these broad phenotypic traits are not recognisable.

My favourite example of this is the diverse range of proteins that have been co-opted as photoreceptors but whose closest genetic relatives carry out a diverse range of functions in the body. But that are a great many examples, already known about, where the phenotypic effects of genes is highly diverged from even very similar genes.

And evolution, the production of a new phenotype, requires the loss of the genetic material for other phenotypes. That means no matter how many mutations you get the production of a new phenotype means losing all but those that contribute to the new phenotype.

It's certainly true that evolution involves a constant loss of genetic material for other phenotypes. Natural selection is a reductive process, it involves throwing away genes, but the other half of evolution is mutation. And mutation involves not just point mutations but also insertions, deletions, and duplications. This generates not just new genetic patterns but also fresh space for new mutations to occur in.

There is simply no reason to believe that the reduction in genetic diversity should outpace the production of new diversity. In fact, it cannot do so.


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Faith
Member
Posts: 25606
From: Nevada, USA
Joined: 10-06-2001
Member Rating: 1.0


Message 55 of 126 (815013)
07-14-2017 1:54 PM
Reply to: Message 54 by Dr Jack
07-14-2017 11:55 AM


Re: Genes are more complex than that
The complexisties you describe don't suggest any kind of change that would promote evolution beyond the Kind, it's all still changes to genes, and even if those functions change they are still genes for those functions, they aren't going to produce something outside the range of what genes do, which would be necessary for evolution beyond the Kind.

It's certainly true that evolution involves a constant loss of genetic material for other phenotypes. Natural selection is a reductive process, it involves throwing away genes, but the other half of evolution is mutation. And mutation involves not just point mutations but also insertions, deletions, and duplications. This generates not just new genetic patterns but also fresh space for new mutations to occur in.

There is simply no reason to believe that the reduction in genetic diversity should outpace the production of new diversity. In fact, it cannot do so.

Thank you for that basic acknowledgement that selection requires loss. As I keep arguing, domestic breeding is still the best example, it doesn't matter where the genetic diversity comes from it still has to be lost by selection to get new phenotypes characteristic of a breed or species, and the end result of the selective processes, which produce those new phenotypes, HAS to be loss.

There HAS to be a point in a series of such evolutionary processes where genetic diversity is reduced to the point that further evolution cannot happen, a hypothetical point in most cases but sometimes real. This is certainly true in old fashioned breeding methods where a purebred is characterized by fixed loci for its defining characteristics. The formation of species in the wild is not so streamlined but you still couldn't get a definitive type without loss of the genetic material for other characteristics.

IF YOU GET MUTATIONS AT THAT POINT you start losing the species, you go back to genetic diversity, you get a motley collection of new phenotypes, not an identifiable species, in breeding you get "mutts" and evolution as the production of definable races, species or breeds stops happening. if you try to call this evolution you are fudging the idea of speciation. You need selection for that. You need selection for evolution. I'm sure there are all kinds of complexities I don't grasp but this has to be the basic pattern.

And again, mutations don't change the basic function of a gene even if that gene involves more than one function. You'd need a structural change of some kind to produce change beyond the basic characteristics of a Kind. Yes I know you're the geneticist but most geneticists are believers in the ToE and have to think in that direction so I expect it to be rationalized no matter what you say. Seems to me you need far more than what you observe to get macroevolution, a change in parts of the genome that define the differences between the Kinds, whatever those might be. For instance, dogs have stiff bodies, cats have flexible bodies. What parts of the genome affect those structural differences?

Edited by Faith, : No reason given.

Edited by Faith, : No reason given.

Edited by Faith, : No reason given.

Edited by Faith, : No reason given.


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Coyote
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Posts: 5905
Joined: 01-12-2008
Member Rating: 4.4


Message 56 of 126 (815014)
07-14-2017 2:01 PM
Reply to: Message 55 by Faith
07-14-2017 1:54 PM


Re: Genes are more complex than that
Fixed it for you:

My religious belief states: "There HAS to be a point in a series of such evolutionary processes where genetic diversity is reduced to the point that further evolution cannot happen."

Science does not agree.


Religious belief does not constitute scientific evidence, nor does it convey scientific knowledge.

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PaulK
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Posts: 12872
Joined: 01-10-2003
Member Rating: 3.5


Message 57 of 126 (815015)
07-14-2017 2:23 PM
Reply to: Message 55 by Faith
07-14-2017 1:54 PM


Re: Genes are more complex than that
quote:

There HAS to be a point in a series of such evolutionary processes where genetic diversity is reduced to the point that further evolution cannot happen, a hypothetical point in most cases but sometimes real.

As I've pointed out in the past this is false. So long as new genetic diversity can arise - and it can - evolution can continue.

quote:

IF YOU GET MUTATIONS AT THAT POINT you start losing the species, you go back to genetic diversity, you get a motley collection of new phenotypes, not an identifiable species

In other words you consider actual species that exist - such as wolves - to not be an identifiable species, just a "motley collection of phenotypes". Which is pretty obviously silly. Obviously it is possible for a species to contain a good deal of genetic diversity - and from that it follows that a species completely lacking in genetic diversity can add genetic diversity while remaining an identifiable species.


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Faith
Member
Posts: 25606
From: Nevada, USA
Joined: 10-06-2001
Member Rating: 1.0


Message 58 of 126 (815016)
07-14-2017 2:35 PM
Reply to: Message 57 by PaulK
07-14-2017 2:23 PM


Re: Genes are more complex than that
No evolution cannot continue. It's all theoretical anyway because mutations don't occur after you have a species or breed, beyond the occasional fluke. If you got a whole bunch of mutations you'd get a "mutt" and maybe from the mutt selection could produce another breed, again theoretically and not likely, but a breed involves the reduction I'm talking about, you cannot get a breed without that reduction and the end result is always going to be loss wherever you are getting evolution or the production of new breeds/species. In many cases fixed loci, which define purebreds, is a point from which no further change is genetically possible at all. Your point is definitional, not real, it doesn't happen in reality.

YOu can't even show a species that developed from mutations beyond a single trait.

Edited by Faith, : No reason given.

Edited by Faith, : No reason given.


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PaulK
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Posts: 12872
Joined: 01-10-2003
Member Rating: 3.5


(1)
Message 59 of 126 (815018)
07-14-2017 2:46 PM
Reply to: Message 58 by Faith
07-14-2017 2:35 PM


Re: Genes are more complex than that
quote:

No evolution cannot continue.

Obviously it is possible for a new variation to appear and to eventually take over the population - or even better for the population to split with the new variation taking over one and being eliminated from the other.

quote:

It's all theoretical anyway because mutations don't occur after you have a species or breed, beyond the occasional fluke

Which is quite enough given a timescale of hundreds of millennia.

The rest of your rambling is pointless. Obviously it is possible to have genetic diversity and have a recognisable species. Obviously a species low on genetic diversity can add more and still be a recognisable species.

quote:

YOu can't even show a species that developed from mutations beyond a single trait

Given that we don't have genetic surveys of species living a few million years ago I wouldn't expect to be able to show it to your satisfaction. All we have is strong evidence that it happened in the genetic similarities and differences of modern species. Which is rather better than denying obvious facts.


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Faith
Member
Posts: 25606
From: Nevada, USA
Joined: 10-06-2001
Member Rating: 1.0


Message 60 of 126 (815019)
07-14-2017 2:50 PM
Reply to: Message 51 by CRR
07-14-2017 8:05 AM


Re: Simple Example
What you are referring to as no change in information meaning no change in the phenotype, is a "neutral" mutation, which got discussed to death on another thread recently. I wish you'd contributed to that discussion. It was about the immune system and the claim that mutations in that system occur frequently and do change function, do produce new immunities against disease. They claim some have hundreds of such beneficial functional mutations. I can't dispute that, can you?

I argued that a mutation changes an allele so that even if it produces a beneficial function (I still doubt this myself but oh well) it has the effect of scattering the benefit in a population. Some individuals have this protection, others have the other protection of the original allele. If you have hundreds of different functions for a given gene due to mutations, which is the claim, then you have fewer individuals having any particular benefit. Which seems like a highly inefficient system that would promote the death of many individuals simply from lack of the particular function needed. But since you seem to have a better grasp of the scientific issues than I do I wish you'd participated on that thread. Maybe I can dig it up.

This one: Message 1 Y.E.C. Model: Was there rapid evolution and speciation post flood?

Edited by Faith, : No reason given.


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