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Author Topic:   A New Run at the End of Evolution by Genetic Processes Argument
NoNukes
Inactive Member


Message 121 of 259 (770964)
10-16-2015 1:25 PM
Reply to: Message 113 by herebedragons
10-16-2015 9:18 AM


Re: What is the definition for speciation in play here.
To be fair, "species" is a very contentious subject.
I agree. That's really part of the basis for the question. It appears that Faith's definition of species is a bunch of homogeneous critters. She concludes that a mutation simply prevents the process of becoming homogeneous and thus cannot be considered in a process of speciation.
But if speciation can be said, as a whole, to require a loss of diversity in all cases, then there ought to be some process or set of processes, and an end result upon which such an accusation can be attached. So I think the question of what is meant by speciation is a valid one even if species itself is not. Clearly dog breeding does not lead to speciation by any reasonable definition that would implicate evolution and/or common descent.
Dog breeders want some homogenity, but they are wary of doing too much inbreeding and in some cases they deliberately seek out the incorporation of diversity. I don't believe Faith's posts acknowledge any such thing. So at least on that basis her description of dog breeding is wrong.
And as countless people have mentioned, natural selection acts only on traits that enhance survival to breed/rear the next generation and thus the expected result is something completely different man enforced selections, where even a bad arrangements of spots is reason even to neuter an animal and remove it from the gene pool. Real speciation is not modeled in ways that are exhibited by dog breeding.
And I'd also point out that the idea that races have any real basis such that different races ought to be considered sub species is not completely without any scientific merit. Beyond that, those groups are only superficially homogeneous anyway.
Edited by NoNukes, : No reason given.

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History will have to record that the greatest tragedy of this period of social transition was not the strident clamor of the bad people, but the appalling silence of the good people. Martin Luther King
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Faith 
Suspended Member (Idle past 1444 days)
Posts: 35298
From: Nevada, USA
Joined: 10-06-2001


Message 122 of 259 (770967)
10-16-2015 2:06 PM
Reply to: Message 110 by RAZD
10-16-2015 7:52 AM


Re: Repeated refutation to Faith's argument
Evolution as a whole sometimes reduces genetic diversity and sometimes increases diversity. This is a two-step feedback response system that is repeated in each and every generation ....
.There are many instances where mutations have added alleles and hence increased diversity. To say whether or not one dominates over the other means you need to do the numbers ... for every species (because each species will have different selection pressure, which is where the reductive pressure occurs).
For the sake of discussion I sometimes accept that mutations can add alleles although I don't really believe it amounts to anything worth mentioning. The point is that even if they do add alleles, even if in fact they ARE the source of all the alleles in all species, it doesn't make a difference to the argument I'm making about evolution bringing about reduced genetic diversity.
It isn't a matter of which "dominates" as you put it. Bloat your species with mutation-caused alleles, all that will do is give you a large scattering of different phenotypes within your population, right? That may be a healthy state for the population but it's not evolution as I'm trying to talk about it.
You need some kind of selection from among those phenotypes to get evolution, don't you? Or do you disagree with that?
I focus on the random type selection of population splits, but it could be natural selection or domestic selection, the genetic situation will be the same, that is, the increasing presence in the population of the selected phenotype or phenotypes and the decreasing presence of the unselected ones. If there is a population split and physical reproductive isolation then the new gene frequencies in the new population will bring out more phenotypes of the high frequency alleles, which may or may not be the same as those in the original population but most likely not, and fewer from the low frequency alleles, and this may be a motley collection for a while too, until after many generations of isolation the new population recombines the whole array of genotypes until a recognizable new collective phenome, if that's the right word, emerges. Or do you disagree with this as a portrait of evolution?
I can't think of any other way you would get a recognizable new species / subspecies myself. If you add alleles you get new phenotypes but scattered within the population, not characteristic of the population as a species or subspecies unto itself, which won't happen until selection and isolation happen. Then when you have this selected and isolated population which is forming into a new species, it must also at the same time be losing a whole bunch of those other phenotypes mutation also brought in. If it doesn't then you don't have selection and if you don't have selection then you don't have evolution. Or do you disagree?
Popular presentations of the ToE picture going from identifiable species to identifiable species so instead of a population of motley different phenotypes selection makes a new population out of those that are selected and eventually eliminates the others. By losing the others genetic diversity is being reduced. If you don't have selection you don't have evolution, you have a species with high genetic diversity and a lot of phenotypic variation. That may be a pretty common situation and a healthy situation for the species, but again I'm trying to talk about what happens when evolution is actively happening, when some individuals are selected over the rest of the population either because of their greater fittedness, or just randomly as some part of a population moves away from the main population or in some other random way gets reproductively isolated from it.
All these different forms of selection produce a new population with new gene frequencies which when recombined for enough generations bring about a new breed or race or variety or species/ subspecies. Do you disagree that selection is required for this to happen? Do you disagree that selection produces a population with reduced genetic diversity?
So you have your new subspecies or variety and now you want to add new mutations, new alleles and go back to the state of a motley collection of different phenotypes that isn't evolving? I thought evolution was supposed to proceed from species to species as if there was nothing to stop the formation of new varieties. Nothing in any popular presentation of the ToE ever supposes the need to add genetic fuel to keep it going.
You want me to say something new. Not until the old is understood.
Edited by Faith, : No reason given.
Edited by Faith, : No reason given.

This message is a reply to:
 Message 110 by RAZD, posted 10-16-2015 7:52 AM RAZD has replied

Replies to this message:
 Message 124 by Blue Jay, posted 10-16-2015 3:07 PM Faith has replied
 Message 125 by PaulK, posted 10-16-2015 3:10 PM Faith has replied
 Message 128 by RAZD, posted 10-16-2015 5:47 PM Faith has replied
 Message 136 by RAZD, posted 10-16-2015 8:45 PM Faith has replied

  
Faith 
Suspended Member (Idle past 1444 days)
Posts: 35298
From: Nevada, USA
Joined: 10-06-2001


Message 123 of 259 (770970)
10-16-2015 2:48 PM
Reply to: Message 112 by herebedragons
10-16-2015 8:30 AM


Re: Some "intelligent" questions
There must be some INTELLIGENT QUESTIONS that could be asked about my claims instead of this you aren't a scientist and you have no right to challenge our sanctified theory attitude you all have.
OK. I have a few questions based on your "genetic depletion" premise.
Nitpick: It's not a "premise," it's the conclusion. I suppose the premise might be something like Evolution isn't really happening unless you have selection ...
Do changes or differences in a gene count as diversity if they are in a non-coding region such as introns or intergenic spacers and have no discernible effect on phenotype?
Let's not get lost in the trees here. Keep it simple. I'm talking about observable recognizable changes in the phenotypic presentation of a species, so if it doesn't affect those changes then no it doesn't count.
And could those polymorphisms allow identity with a particular group or population to be adequately made? In other words, what criteria identifies a sub-species with the larger species group?
I'm more or less assuming you know the history of the formation of a population. If you don't know its history then I don't know how you identify the relationships between different groups. In fact ideally to understand what I'm getting at you would be creating the populations yourself and tracking them.
Would you predict that a family such as Orchidaceae or Asteraceae, with more than 20,000 species each, would have low diversity or high diversity?
In the species/family as a whole sounds like high diversity. But I'm not interested in what happens to the species/family as a whole. My focus is on what happens to selected subpopulations of that family because that's where you get the phenotypic changes based on the new gene frequencies, along with the reduced genetic diversity (in relation to the parent population) that brings about a new variety or subspecies.
Should breeding programs with orchids continue attempting to create new varieties, or have they run out of diversity yet?
I have no way of knowing that. As I proposed with the Pod Mrcaru lizards that got the big heads in thirty years, to find out if they have more ability to evolve you'd have to select another set of pairs from that population and isolate them on another island. If they change in some recognizable way then they had genetic diversity to spare.
If they have not run out of diversity, then why have they not,
with more than 20,000 species.
Plants may be genetically different enough from the animals I have in mind to need a different explanation, I don't know, but if animals haven't run out of genetic diversity after beaucoup population splits into beaucoup new subspecies, it's because they started out with tons of heterozygous genes and no junk DNA.
Or what about Drosophilidea which has over 3,000 species, some of which are used extensively in genetic studies and are known for the high amount of diversity they exhibit? Your idea seems to predict Drosophila melanogaster should be depleted of genetic diversity, but its not. Drosphilidea, Ochidaceae and Asteraceae all have had way more branching events than Felidea, of which cheetahs are a member; yet cheetahs suffer genetic depletion because of those branching events and the others mentioned do not. Why?
You know plant genetics and I don't and fruit flies too I guess. Sounds like they have lots more genetic possibilities than animals. Lots of stuff like polyploidy or that sort of thing? Unless the principles involved are entirely different, however, I would assume that plants too would eventually run out of genetic diversity.
Since total genetic diversity, which it seems to mean the sum total of all the alleles at all loci in a population, is for all practical purposes impossible to measure at this time (I don't think you realize what a daunting task measuring something like that would be) could you recommend a surrogate measure? Are there genetic markers that would provide a good estimate of genetic diversity?
The number of fixed loci for the characteristic traits is the best measure I can think of. The more fixed loci the less genetic diversity. The fewer alleles per locus the less genetic diversity. But again I'm thinking of the situation where you know the history of the formation of a population.
What method do you use to determine how closely related populations are? If a population splits and the daughter population becomes a new sub-species and then that daughter population splits again and the split becomes a grand-daughter population, the grand-daughter population will be more closely related to the daughter population than it is to the parent population, right? So, what criteria do you use to determine which is the daughter population and which is the grand-daughter population and can you give an example of this methodology being applied to real populations?
See above. I'm not interested in how they are related to each other except as you know the history of their descent one from another and then I'd predict reduced genetic diversity from population to population as new varieties are developed.
Further expanding the above idea, if population splits occurred very rapidly after the flood bottleneck we should now have great, great, great, great, great grand-daughter populations living as extant sub-species. If fact, the grand-daughter populations would have split off to make aunt and great aunt populations as well.
Would you be able determine ancestry based on genetic diversity data? Here's what I mean... you suggest that some population in the past had very high genetic diversity and as sub-populations split off from that population, they lost diversity. So, it would seem that groups with high genetic diversity are more ancestral than populations with low diversity, which would be the derived form. In other words, could we take the dog group and arrange it based on genetic diversity, come up with some sort of branching tree-like structure and have a good idea how the dog group developed? Based solely on genetic diversity. Can you give an example of a study that used that or a similar methodology?
Far as I know nobody has a reason to study this sort of thing. But there's no reason to think the original population from which all the subspecies diverged maintained its ancestral genetic diversity. It too would have been reduced in numbers as the daughter populations diverged from it so it too would have had new gene frequencies and lost alleles and undergone phenotypic change. So I don't know how you'd identify any group from any other. Perhaps geneticists will get to that point. But I also don't see why it matters. Certainly doesn't matter to my argument. But my argument does need you to know the history of how different subspecies formed because the prediction is that the newest, at least in a chain of populations, will be the least genetically diverse.
Finally, in cladistics we refer to all species that share a common ancestor as a monophyletic group. Your scenario would have the same situation; all species or sub-species that descended from the original ark pair would form a monophyletic group or clade. What criteria would you use to determine which monophyletic group a sub-species belongs to?
Again you are asking questions that I don't think can be answered, but whether they can or can't it has nothing to do with the argument I'm making.
For example, does a fox and its kin belong to the wolf/dog clade or does it belong to a different clade (maybe the fox clade) and what criteria do you use to determine that?
See above.
I am not sure you will consider any of these questions to be "intelligent," but these are the kinds of things I find troubling about your scenario. These are issues that I don't think your "genetic depletion model" can address, but the standard genetic model does address quite well. How could I use this model in my own population study? Why should I adopt this model when the model I already have appears to work so well, and I don't see any practical way to apply this model (nor does it even seem plausible)?
I really have no idea what the problem is. Just as a general statement, if one model is true and another false you'd be better off with the true one even if you've adapted to the false one, right? But all I'm interested in is what a sequence of new subspecies that require reduced genetic diversity does to the ToE.
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 112 by herebedragons, posted 10-16-2015 8:30 AM herebedragons has replied

Replies to this message:
 Message 140 by herebedragons, posted 10-16-2015 10:26 PM Faith has replied

  
Blue Jay
Member (Idle past 2698 days)
Posts: 2843
From: You couldn't pronounce it with your mouthparts
Joined: 02-04-2008


(1)
Message 124 of 259 (770974)
10-16-2015 3:07 PM
Reply to: Message 122 by Faith
10-16-2015 2:06 PM


Re: Repeated refutation to Faith's argument
Hi, Faith.
Faith writes:
It isn't a matter of which "dominates" as you put it. Bloat your species with mutation-caused alleles, all that will do is give you a large scattering of different phenotypes within your population, right?
What if we "bloat our species with mutation-caused alleles" after the population has split into two separate populations?
Couldn't we hypothetically accumulate enough new alleles via mutation that one of the daughter populations eventually ends up with higher allele diversity than the original, pre-split population had?

-Blue Jay, Ph.D.*
*Yeah, it's real
Darwin loves you.

This message is a reply to:
 Message 122 by Faith, posted 10-16-2015 2:06 PM Faith has replied

Replies to this message:
 Message 127 by Faith, posted 10-16-2015 5:16 PM Blue Jay has replied

  
PaulK
Member
Posts: 17822
Joined: 01-10-2003
Member Rating: 2.2


(1)
Message 125 of 259 (770975)
10-16-2015 3:10 PM
Reply to: Message 122 by Faith
10-16-2015 2:06 PM


Re: Repeated refutation to Faith's argument
Faith, I would like to congratulate you on actually making a productive post which better explains your position.
So here's something to think about. Wolves are not a hitch-potch of different phenotypes. Yet - even if you allow a role for mutations they must contain a good deal of the genetic variability that leads to the huge variety of the different breeds of dogs.
Doesn't this show that genetic variation does not automatically produce your "hotch-potch" ?

This message is a reply to:
 Message 122 by Faith, posted 10-16-2015 2:06 PM Faith has replied

Replies to this message:
 Message 129 by Faith, posted 10-16-2015 5:47 PM PaulK has replied

  
Taq
Member
Posts: 9973
Joined: 03-06-2009
Member Rating: 5.6


(1)
Message 126 of 259 (770985)
10-16-2015 4:42 PM
Reply to: Message 108 by Faith
10-16-2015 5:42 AM


Re: A simple refutation to Faith's argument
Faith writes:
The situation of fixed loci, only one allele, meaning a pair of them, per locus, is the dire situation of the cheetah, from which recovery is not expected by conservationists at all.
I would think that cheetahs have about the same mutation rate as humans at 35 to 50 mutations per individual per generation. If 10% of their genome is made up of alleles that affect phenotype, then 3 to 5 of those mutations will produce a new alleles at the genotype level. That's 3 to 5 new alleles per individual. This is an unavoidable consequence of mutations.
But the REALLY main point is that since evolution does reduce genetic diversity . . .
It appears we have proven you wrong on that point.
Edited by Taq, : No reason given.

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Faith 
Suspended Member (Idle past 1444 days)
Posts: 35298
From: Nevada, USA
Joined: 10-06-2001


Message 127 of 259 (770988)
10-16-2015 5:16 PM
Reply to: Message 124 by Blue Jay
10-16-2015 3:07 PM


Adding alleles prevents evolution from occurring
What if we "bloat our species with mutation-caused alleles" after the population has split into two separate populations?
Couldn't we hypothetically accumulate enough new alleles via mutation that one of the daughter populations eventually ends up with higher allele diversity than the original, pre-split population had?
Yes, but it won't have been evolving, it will be in that condition before the split of having many different phenotypes scattered through the population.
I'm arguing that evolution requires selection (of some sort, random or otherwise) and selection has to select and isolate some of those phenotypes from the rest of them, which means developing the selected phenotypes from their higher frequency alleles, and suppressing or eliminating the others with their lower frequency alleles so that eventually as all the genotypes get recombined over the generations a new look to the population should emerge that is dominated by the high frequency alleles. So if and when this daughter population does begin to evolve it has to go through the same selection processes that reduce genetic diversity.
If you keep adding alleles it simply isn't evolving. Which is OK of course, but it isn't evolution. Evolution requires selection requires reduced genetic diversity.
Edited by Faith, : No reason given.

This message is a reply to:
 Message 124 by Blue Jay, posted 10-16-2015 3:07 PM Blue Jay has replied

Replies to this message:
 Message 130 by PaulK, posted 10-16-2015 5:53 PM Faith has replied
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 Message 139 by Dr Adequate, posted 10-16-2015 9:47 PM Faith has not replied

  
RAZD
Member (Idle past 1405 days)
Posts: 20714
From: the other end of the sidewalk
Joined: 03-14-2004


(1)
Message 128 of 259 (770990)
10-16-2015 5:47 PM
Reply to: Message 122 by Faith
10-16-2015 2:06 PM


Understanding Faith's argument
You want me to say something new. Not until the old is understood.
Okay let's start with this issue: The Faith Postulate -- evolution results in loss of genetic diversity through the loss of alleles as species divide into isolated sub-populations, and eventually species are so depleted they can no longer evolve new types.
Premise 1: every time a population splits for whatever reason, one population does not have all the alleles that the other population has - or that the parent population had.
We'll call this the "Secondary Population" for clarity (with the parent\remaining population being the "Primary Population"). Premise 2: that this loss of alleles means that the frequency of alleles in the Secondary Population is different from the frequency of alleles in the Primary Population. Conclusion 1: therefore the distribution of different phenotype traits (the makeup of the phenome) in the first generation of the Secondary Population will be different from the distribution of different phenotype traits (the makeup of the phenome) in the Primary Population. Premise 3: this different distribution will give rise to new phenotype trait mixes in the second generation, due to breeding between the first generation types having different distributions from the Primary Population. Premise 4: over time this process would continue and more new phenotype trait mixes would be generated. Conclusion 2: over time (after several generations) a new phenotype trait mix becomes the dominate "Type" of the Secondary Population, one that is distinctly different from the Primary Population dominant "Type" (the characteristic phenotype mix that is used to define the population -- not identical individuals, but similar on the majority of traits). Premise 5: the dominance of the new "Type" will drive alleles that were previously dominant into lower and lower frequencies until they become eliminated from the phenome of the Secondary Population. Premise 6: loss of previously dominant alleles will cause the Secondary Population to become reproductively incompatible with the Primary Population. Conclusion 3: a new subspecies is formed that has less genetic diversity than the original species. Conclusion 4: as populations continue to divide this will result in less and less genetic diversity until the resultant subspecies become non-viable and go extinct, thus ending evolution. So, does this or does this not describe your argument?
Enjoy
Edited by RAZD, : .
Edited by RAZD, : hidden comments

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This message is a reply to:
 Message 122 by Faith, posted 10-16-2015 2:06 PM Faith has replied

Replies to this message:
 Message 167 by Faith, posted 10-19-2015 5:13 PM RAZD has replied

  
Faith 
Suspended Member (Idle past 1444 days)
Posts: 35298
From: Nevada, USA
Joined: 10-06-2001


Message 129 of 259 (770991)
10-16-2015 5:47 PM
Reply to: Message 125 by PaulK
10-16-2015 3:10 PM


Re: Repeated refutation to Faith's argument
Faith, I would like to congratulate you on actually making a productive post which better explains your position.
A compliment from PaulK? Will wonders never cease? Well, thanks.
So here's something to think about. Wolves are not a hitch-potch of different phenotypes. Yet - even if you allow a role for mutations they must contain a good deal of the genetic variability that leads to the huge variety of the different breeds of dogs.
As I mentioned (to HBD I think), even if we know the ancestor type of a given species there's no guarantee the living representative of that ancestor is all that much like the original, since due to the formation of so many daughter populations from that original stock, in this case the enormous variety of dogs, that population too will most likely have undergone enough of a population reduction to have also changed. I don't think we can even assume the wolves have greater genetic diversity than any random population of mutts.
But nevertheless there is a valid point in your question. I usually think of it in relation to a population like the gnus or wildebeests which I think are divided into three different species or subspecies but form enormous homogeneous herds. Since they don't seem to branch off frequently my guess would be the original population has very high genetic diversity, and depending of course on how large the number of founders of the daughter populations was, even they could still have pretty high genetic diversity.
All three of these different populations are very homogeneous and not characterized by that motley collection of different phenotypes yet as I say I doubt any of them is in a condition of seriously reduced genetic diversity. SOME reduction would have to be the case in a daughter population that began with a small number of founders, but we don't have to be thinking of fixed loci even there. Maybe of course, but maybe not.
SO, this condition of motley phenotypes is a stage that eventually gives way to the homogeneous result of recombination over generations. This would not happen of course if mutations were springing up with the rapidity I've been imagining so far. What is more likely to be the case is that there are occasional changes in individuals that get recombined before the differences really make a difference.
The main time this motley stage occurs, I surmise, is soon after a population split, in a daughter population that has big enough changes in gene frequencies to produce a whole new array of new phenotypes in the first few generations of reproductive isolation. All due to the new gene frequencies, alleles coming to expression that didn't come to expression in the original population because there they were low frequency whereas in the new population they are high enough frequency to emerge. I'm sure it's more complicated than this but still should be generally the case.
SO, first stage after split all the individuals of the new population look exactly like those in the old population.
After a few generations of sexual recombination, the new gene frequencies will start producing new phenotypes.
This should go on for a while with new phenotypes showing up and forming the motley scattered look I was talking about.
Then eventually over many generations of sexual recombination of all the different genotypes eventually a new "phenome" should emerge that characterizes the new population as a whole that is distinct from the phenome of the original population. Different body characteristics, different coloring etc etc.
Even if wolves do have mutations they would maintain their homogeneity by just recombining them into the group phenome. It would take a LOT of mutations to create that motley effect, and it's only if a small subset of wolves diverges into reproductive isolation that the same phenomenon could show up in them. Could, if they do have a lot of genetic diversity to begin with.
Edited by Faith, : No reason given.

This message is a reply to:
 Message 125 by PaulK, posted 10-16-2015 3:10 PM PaulK has replied

Replies to this message:
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PaulK
Member
Posts: 17822
Joined: 01-10-2003
Member Rating: 2.2


Message 130 of 259 (770992)
10-16-2015 5:53 PM
Reply to: Message 127 by Faith
10-16-2015 5:16 PM


Re: Adding alleles prevents evolution from occurring
But quite obviously you are incorrect.
There's nothing in your argument that shows that adding alleles interferes with evolution at all.
Even more, as I have explained to you most of the additions will be after the speciation event, when the population is growing and when it is large (the first because selection is relaxed, the second because mutations occur with each birth - a larger population means more births, means more mutations)
I ask again, how can mutations that occur after the process of speciation is complete possibly interfere in the process of speciation ? How can you even imagine that it is possible ?

This message is a reply to:
 Message 127 by Faith, posted 10-16-2015 5:16 PM Faith has replied

Replies to this message:
 Message 131 by Faith, posted 10-16-2015 5:58 PM PaulK has replied

  
Faith 
Suspended Member (Idle past 1444 days)
Posts: 35298
From: Nevada, USA
Joined: 10-06-2001


Message 131 of 259 (770993)
10-16-2015 5:58 PM
Reply to: Message 130 by PaulK
10-16-2015 5:53 PM


Re: Adding alleles prevents evolution from occurring
It's exactly the same situation as having your golden retriever puppy show up mottled gray or your Freisian colt chocolate brown. They violate the breed and can't be sold.
Edited by Faith, : No reason given.

This message is a reply to:
 Message 130 by PaulK, posted 10-16-2015 5:53 PM PaulK has replied

Replies to this message:
 Message 133 by NoNukes, posted 10-16-2015 6:12 PM Faith has not replied
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 Message 166 by PaulK, posted 10-19-2015 4:54 PM Faith has replied

  
PaulK
Member
Posts: 17822
Joined: 01-10-2003
Member Rating: 2.2


(1)
Message 132 of 259 (770995)
10-16-2015 6:11 PM
Reply to: Message 129 by Faith
10-16-2015 5:47 PM


Re: Repeated refutation to Faith's argument
The problem remains. The genetic diversity is certainly there but this state of "motley phenotypes" is not observed. All you've produced is what you call "mental conjuring", and in this case it is at odds with the evidence.
Let me make a basic point again. Natural species are not the same as artificial breeds. Even in the rare cases where genetic diversity has been seriously reduced by extreme bottlenecks the selective element that produces breeds is missing.
The only case where you might get a collection of mixed and diverging phenotypes is adaptive radiation, where a species splits multiple ways. However this requires weak selection and multiple open niches in the ecosystem.
In general there is no reason to expect any "motley effect". Instead you should expect to see a slow piecemeal accumulation of change. Which really is much like dog breeding as it actually occurred. Breeders didn't find a new breed suddenly appearing - each breed was developed over a period of time.

This message is a reply to:
 Message 129 by Faith, posted 10-16-2015 5:47 PM Faith has not replied

  
NoNukes
Inactive Member


(1)
Message 133 of 259 (770996)
10-16-2015 6:12 PM
Reply to: Message 131 by Faith
10-16-2015 5:58 PM


Re: Adding alleles prevents evolution from occurring
It's exactly the same situation as having your golden retriever puppy show up mottled gray or your Freisian colt chocolate brown. They violate the breed and can't be sold.
Just thought this comment was worth repeating.

Under a government which imprisons any unjustly, the true place for a just man is also in prison. Thoreau: Civil Disobedience (1846)
History will have to record that the greatest tragedy of this period of social transition was not the strident clamor of the bad people, but the appalling silence of the good people. Martin Luther King
If there are no stupid questions, then what kind of questions do stupid people ask? Do they get smart just in time to ask questions? Scott Adams

This message is a reply to:
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PaulK
Member
Posts: 17822
Joined: 01-10-2003
Member Rating: 2.2


Message 134 of 259 (770997)
10-16-2015 6:14 PM
Reply to: Message 131 by Faith
10-16-2015 5:58 PM


Re: Adding alleles prevents evolution from occurring
No, it isn't. The variations will be smaller (so that they would likely be acceptable) and there is no buyer and no selling.

This message is a reply to:
 Message 131 by Faith, posted 10-16-2015 5:58 PM Faith has not replied

  
Blue Jay
Member (Idle past 2698 days)
Posts: 2843
From: You couldn't pronounce it with your mouthparts
Joined: 02-04-2008


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Message 135 of 259 (771003)
10-16-2015 7:50 PM
Reply to: Message 127 by Faith
10-16-2015 5:16 PM


Re: Adding alleles prevents evolution from occurring
Faith writes:
Blue Jay writes:
Couldn't we hypothetically accumulate enough new alleles via mutation that one of the daughter populations eventually ends up with higher allele diversity than the original, pre-split population had?
Yes, but it won't have been evolving, it will be in that condition before the split of having many different phenotypes scattered through the population.

If you keep adding alleles it simply isn't evolving. Which is OK of course, but it isn't evolution. Evolution requires selection requires reduced genetic diversity.
Okay, so you believe that mutations would allow for an increase in genetic diversity, but that it wouldn’t count as evolution. I would just say we could call it something other than "evolution" and leave it at that, but I don’t think your skepticism toward evolution only boils down to a semantic issue, so let’s try something else.
Maybe let’s stop thinking of selection as an active process that reduces genetic diversity. Instead, think of it as a set of boundaries that constrain which mutations work and which ones don’t. So, the only mutations that accumulate are ones that fit within the constraints of the selection boundaries.
The idea is that, when selection constraints are really stringent, fewer mutations can accumulate, so allele diversity will decrease.
When selection constraints are really lax, more mutations can accumulate, and allele diversity will increase.
That’s what we’ve been trying to explain about mutations outpacing or dominating natural selection and vice versa.
Am I making sense yet, or do I still sound wrong to you?

-Blue Jay, Ph.D.*
*Yeah, it's real
Darwin loves you.

This message is a reply to:
 Message 127 by Faith, posted 10-16-2015 5:16 PM Faith has not replied

  
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