Register | Sign In


Understanding through Discussion


EvC Forum active members: 60 (9208 total)
0 online now:
Newest Member: Skylink
Post Volume: Total: 919,429 Year: 6,686/9,624 Month: 26/238 Week: 26/22 Day: 8/9 Hour: 0/2


Thread  Details

Email This Thread
Newer Topic | Older Topic
  
Author Topic:   A test for claimed knowledge of how macroevolution occurs
RAZD
Member (Idle past 1655 days)
Posts: 20714
From: the other end of the sidewalk
Joined: 03-14-2004


(1)
Message 541 of 785 (856171)
06-28-2019 8:24 AM
Reply to: Message 528 by Faith
06-27-2019 5:44 PM


change over time, each generation changes
As usual you keep ignoring all the arguments and examples I've given that prove it is necessary to lose genetic diversity to get new phenotypes. All you are doing is trying to sound authoritative without actually saying anything.
No, I dont ignore your falsified argument, I just point out that it is falsified and thus irrelevant to reality.
What you need to get new phenotypes is new traits. You don't get this by remixing old traits, you get them from changes -- mutations. Each and every generation's gene pool changes, generation after generation, and this provides changes to phenotypes over time.
For example the Pelycodus increase in body size generation after generation until the point is reached that the smallest individual is larger than the largest individual of the original population. We also see that the spread of size from smallest to largest changes with each generation, sometimes increasing in spread, sometimes decreasing.
It should be obvious to anyone with open eyes that the increase in body size until the whole population is larger than the original population is not just due to a loss of genetic material for body size, but that the genes for body size are modified for increased size: changes in the overall size that prove beneficial for survival or reproduction. The ToE explains this, your model only explains the loss of smaller sizes, ie only half of what happened.
No, I've made the case, and made it many many times over many threads and even in this thread, and I have indeed presented the evidence of domestic breeding which is about as clear a description as you can get of what happens to develop new phenotypes, and I've given plenty of illustrations of that same thing happening in the wild. Interesting that you never discuss any of this.
And every time you have been told and demonstrated why domestic breeding does not model natural evolution. You have been shown over and over how mutations add to diversity, and increased opportunity for species, like the pocket mice. These examples invalidate your argument, and when added to your cherry picked examples they serve to show your explanation is incomplete and less accurate than the explanation provided by the ToE which explains all the evidence.
If only you would open your eyes and look at all the evidence.
Enjoy
Edited by RAZD, : .

we are limited in our ability to understand
by our ability to understand
RebelAmerican☆Zen☯Deist
... to learn ... to think ... to live ... to laugh ...
to share.


Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click)

This message is a reply to:
 Message 528 by Faith, posted 06-27-2019 5:44 PM Faith has not replied

  
Percy
Member
Posts: 22933
From: New Hampshire
Joined: 12-23-2000
Member Rating: 7.1


(1)
Message 542 of 785 (856174)
06-28-2019 9:15 AM
Reply to: Message 532 by Faith
06-28-2019 12:48 AM


Re: Genetic loss is a necessity
Your ideas have significant and glaring errors. It's understandable that you have for years resisted modifying them in any way because the ideas are so wrong, so at odds with reality, that fixing them isn't possible. They have to be discarded.
One glaring error is your idea that two populations with all the same genes and chromosomes but with different allele frequencies, or one population with reduced allele diversity, can be different species. This is dead wrong. Changing allele frequencies or removing alleles entirely from a population can never create a new species, not genetically. New breeds, sure, but new species, no. The whole idea of species creation through reductions in allele diversity was fatally flawed from the start.
Another glaring error is your idea that mutation cannot cause change. Given a fixed set of chromosomes and genes, allele frequency is in control and any mutation that changes an allele can cause change. Just as normal reproduction causes change by modifying the allele distribution, a mutation in an allele also modifies the allele distribution.
--Percy

This message is a reply to:
 Message 532 by Faith, posted 06-28-2019 12:48 AM Faith has not replied

  
RAZD
Member (Idle past 1655 days)
Posts: 20714
From: the other end of the sidewalk
Joined: 03-14-2004


(2)
Message 543 of 785 (856176)
06-28-2019 9:33 AM
Reply to: Message 529 by Faith
06-27-2019 6:18 PM


Re: The genetic loss idée fixe vs reality
Breeders cull traits to preserve their breeds, for sure, but traits are not necessarily mutations, in fact most of the time all they are doing is choosing to mate individuals that have the positive traits they desire and don't have to focus on the unwanted traits. You haven't shown, and cannot show, that mutations are ever a problem in breeding, at any stage of the process. ...
Exactly, they cull out the new mutations to preserve the breed. Natural selection operates on a different paradigm -- traits that are useful for survival or desirable for reproduction, it not could care less about preserving a phenotype, just what ever works. It doesn't matter if it is new or old.
This again is why breeding is not a model for evolution.
... You assume that all traits are the result of mutations, and that always has been an assumption and remains an assumption but you take it so for granted it is just about impossible to get you to consider any other way of looking at it. ...
We know mutations modify traits and cause new phenotypes, and have known this for decades.
... Well, that is of course the standard problem in paradigm conflicts. And getting the Old Guard to rethink their stuff is asking WAY too much, isn't it?
When you have evidence against you and no supporting evidence, yes.
And here we have the very center of the paradigm clash. You seem to be unable to think at all about any of this without assuming evolution and assuming mutation as the fuel of that evolution. You think the traits of the chosen breed MUST have evolved by mutation from the parent stock. You can't prove this, you assume it, it's simply an article of the ToE faith that isn't questioned.
Because it is based on evidence. We don't see traits for floppy ears, spotted color fur and waggy tails in wolves. We don't see them in wild foxes either, but a Russian breeding program to make tamer and thus easier to raise for the fur trade ended up with those traits -- due to mutations that decreased the adrenaline and increased serotonin in the foxes.
We know there are genetic differences between wolves to dogs and differences between breeds. You don't get Great Danes from wolves by throwing out dachshund dog traits and vice-versa because those traits don't exist in wolf genomes. You get them from mutations.
My contrasting model/theory is that there is no difference whatever in the genetic material between generations, ...
And in this you are wrong.
No mutations needed, dear Razz. ...
But you cannot ignore that they are there if you want to model reality. It's not that they are needed (which is wrong paradigm thinking) but that they are there, and thus they need to be included in a complete explanation.
We know that they are there in every generation, we know that this changes the gene pool for every generation, and we know that they need to be considered in any explanation of observed changes in a species, because anything less would be a half vast explanation.
It's a different paradigm from your evolutionary pattern, ...
That doesn't cover all the evidence, nor explain all that is observed, and therefore not useful.
I just wish you would open your eyes.
Enjoy

we are limited in our ability to understand
by our ability to understand
RebelAmerican☆Zen☯Deist
... to learn ... to think ... to live ... to laugh ...
to share.


Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click)

This message is a reply to:
 Message 529 by Faith, posted 06-27-2019 6:18 PM Faith has not replied

  
herebedragons
Member (Idle past 1107 days)
Posts: 1517
From: Michigan
Joined: 11-22-2009


(3)
Message 544 of 785 (856179)
06-28-2019 9:53 AM
Reply to: Message 539 by Faith
06-28-2019 2:42 AM


Re: The genetic loss idée fixe vs reality
I am actually in the central coastal area of California right now, working with a collaborator on a sequencing project. Last night I visited Point Lobos State Park where you are supposed to be able to see sea lions. I could hear them barking, but they were too far away to see them
I learned this week that California has over 2,000 endemic plant species and one of the most diverse plant communities in the US. There are some very interesting plant types that I have never seen before being from the Midwest. But there were many plants that looked familiar, but not quite... They were just different enough that I knew they weren't a species I was familiar with.
Diversity is probably the number 1 issue that biologists study. It is usually the first question you ask when addressing an issue; "How much diversity is there?", "How is the diversity distributed or structured?", "How does the diversity of this organism compare to the diversity of other organisms?" Diversity is a huge question in biology. It is one of the major features we study. We leverage diversity to make discoveries about processes and gene function. For example, if you want to know what gene controls a particular trait, you first make a diversity panel with lots of individuals that vary for that trait.
The short point here is that biologists have been studying diversity for a long time... and it is still a huge area of study. New genomic tools are allowing us to look at diversity on a whole genome level, not just at individual loci. If your model were correct, we would be finding that out. Instead, we are finding MORE and more diversity. We are discovering diversity we did not previously know existed (unculturable organisms for example) and how diversity looks at a genetic level - not just alleles, but whole genomes.
Here is an example from a 2018 paper looking at the diversity in a plant pathogenic bacterium, Clavibacter michiganensis . Clavibacter michiganensis has been separated into several subspecies based primarily on host range. Remember that bacteria are haploid, non-sexually reproducing organisms - which is also true for roughly 75% of the species on earth. Any model of diversity needs to account for haploid diversity or it is pretty meaningless.
image
**Unfortunately, I can't get the image to display in the thread, but the link should open it in a new window.**
Each genome is a single circular chromosome. The colored blocks represent locally collinear regions - not necessarily specific genes. Subsp. insidiosus (Cmi) is the primary organism being studied, so it is at the top and is the reference genome. Blocks that are above the horizontal line are oriented in the same direction as the reference; those below the line are oriented in the reverse direction. Lines between genomes indicate synteny between blocks on different genomes.
On the Cmc (subsp. capsici) chromosome, there is a section that is below the line that includes a small red block, a large yellow block and a small green block. It is located at the opposite end of the chromosome for Cmi. At some time in the past, it was cut out and reinserted at a different locus in the reverse orientation. In addition, the blocks are different from one another - relative homology is shown in the figure but it is really hard to see.
As you can see, Cms (subsp. sepidonicus) is the most diverse - ie. has the most rearrangements. Interestingly, all the other subspecies have an epiphytic phase, where they can survive on leaves until conditions are right for infection. But Cms does not have an epiphytic phase, but can only survive within potato tubers.
I know one of your objections will be (besides not being able to read it) that this is for bacteria so it doesn't apply to your argument. Well... 1) 75% of the diversity of life on earth works like this, so any model that explains diversity, needs to include haploid, non-sexually reproducing species. and 2) we do see these same patterns in sexually reproducing eukaryotes, it is just much more difficult to work with and display in a readable format.
It just doesn't make any sense that this variation is all built into the genome and just shuffled around by recombination.
I think what I need to do is try to put together a lengthy article trying to cover the whole shebang since I now think I'm leaving too much out of these discussions.
No, what you need to do is come up with evidence that it matches what we observe. Show us a study that supports your position.
HBD

Whoever calls me ignorant shares my own opinion. Sorrowfully and tacitly I recognize my ignorance, when I consider how much I lack of what my mind in its craving for knowledge is sighing for... I console myself with the consideration that this belongs to our common nature. - Francesco Petrarca
"Nothing is easier than to persuade people who want to be persuaded and already believe." - another Petrarca gem.
Ignorance is a most formidable opponent rivaled only by arrogance; but when the two join forces, one is all but invincible.

This message is a reply to:
 Message 539 by Faith, posted 06-28-2019 2:42 AM Faith has replied

Replies to this message:
 Message 555 by Faith, posted 06-29-2019 2:03 AM herebedragons has replied

  
PaulK
Member
Posts: 17909
Joined: 01-10-2003
Member Rating: 7.2


(1)
Message 545 of 785 (856182)
06-28-2019 10:20 AM
Reply to: Message 539 by Faith
06-28-2019 2:42 AM


Re: The genetic loss idée fixe vs reality
quote:
As I was thinking through this list it hit me that Mutation and gene flow ADD to the genetic variability, and must create a scattered effect of phenotypes. What makes for a homogeneous species, on the other hand, is the subtractive processes of selection.
I will point out that species are never entirely homogenous. There are often subspecies - populations distinctive enough to be considered worthy of their own label, but not separate species. But there are also more widely-spread variations. Mutation adds to this variation and gene flow is more about spreading variation around.
However, some traits do become fixed in a species and that is usually due to selection. (But drift fixes a lot of neutral variation at the genetic level)
But again we come to the fact that we do have all this variation. It only starts to run out when there is very heavy selection or a very severe bottleneck.
And in both cases that is exactly what we would expect if evolution were true. Drastically speeding up subtractive processes alone will produce a net subtraction. That should be completely obvious.
But it is also obvious that subtractive processes alone don’t tend to produce much phenotypic change. The elephant seal bottleneck was in historical times but it hasn’t affected the phenotype much. Breeding relies more on selection than simply reducing the population - and indeed, mutation has provided variation that breeders have selected. Even so, breeding has not produced a new species of animal.
You say that there is no evidence but this is really quite devastating evidence. Your own chosen examples do nothing to support your view and tend to favour the opposing viewpoint.
How then can you complain that we don’t change our minds ? The evidence is firmly on our side. Even the evidence that you raise.

This message is a reply to:
 Message 539 by Faith, posted 06-28-2019 2:42 AM Faith has not replied

  
Sarah Bellum
Member (Idle past 845 days)
Posts: 826
Joined: 05-04-2019


Message 546 of 785 (856185)
06-28-2019 11:15 AM
Reply to: Message 526 by Faith
06-27-2019 5:19 PM


Re: Genetic loss is a necessity
But clearly much has been gained, and not just by "hybridization"! The wheat that is cultivated nowadays is substantially different than the types of grain that grew before humans began farming.
I was expecting you to say that since this is all a result of interference by an intelligent agency (humans) that doesn't prove that evolution happens naturally, without interference by an intelligent agency.
But of course new species have been observed to evolve, so ...

This message is a reply to:
 Message 526 by Faith, posted 06-27-2019 5:19 PM Faith has not replied

  
Taq
Member
Posts: 10296
Joined: 03-06-2009
Member Rating: 7.4


(2)
Message 547 of 785 (856186)
06-28-2019 11:23 AM
Reply to: Message 527 by Faith
06-27-2019 5:27 PM


Re: Kinds reproduce according to their kind
Faith writes:
Yes it's possible to select all mutations for the new species, but whatever is selected requires the loss of other genetic material that is excluded from the new phenotypes.
How is that a problem?
You still end up with an overall loss of genetic variability, even if you manage to get a new population completely made up of brand new mutations.
Again, how is that a problem? Why would an evolving species need to keep ancestral alleles in order for evolution to happen?

This message is a reply to:
 Message 527 by Faith, posted 06-27-2019 5:27 PM Faith has not replied

  
Taq
Member
Posts: 10296
Joined: 03-06-2009
Member Rating: 7.4


Message 548 of 785 (856192)
06-28-2019 11:42 AM
Reply to: Message 532 by Faith
06-28-2019 12:48 AM


Re: Genetic loss is a necessity
Faith writes:
Except that you aren't going to get the new population unless you have the decrease. Pretty obvious if you think about domestic breeds. You could start with a very homogeneous original/parent population with a distinct appearance and high genetic diversity, a species in itself, but getting a NEW breed requires a portion of that original population to be separated from it and isolated for breeding just within itself. THEN you get a new species or new breed.
You are forgetting about the mutations that happen along the way which increases genetic diversity. If you have both increases and decreases then you have the same amount of diversity through the whole process. Some alleles are added and some are removed. They balance each other out.

This message is a reply to:
 Message 532 by Faith, posted 06-28-2019 12:48 AM Faith has not replied

  
Taq
Member
Posts: 10296
Joined: 03-06-2009
Member Rating: 7.4


(2)
Message 549 of 785 (856195)
06-28-2019 11:48 AM
Reply to: Message 539 by Faith
06-28-2019 2:42 AM


Re: The genetic loss idée fixe vs reality
Faith writes:
As I was thinking through this list it hit me that Mutation and gene flow ADD to the genetic variability, and must create a scattered effect of phenotypes. What makes for a homogeneous species, on the other hand, is the subtractive processes of selection.
Humans aren't homogenous. No species is homogenous. Every species has alleles for different genes. There is genetic diversity among cheetahs, even if it is low.
What happens is that a set of traits is randomly selected by the separation of a portion of the parent population to become a daughter population. That random separation of a certain group of individuals forms a new gene pool with new gene frequencies that when blended together over some number of generations of breeding brings out a distinctively new species from a new group of phenotypes created by the new gene frequencies in sexual recombination for those generations. It's the same process as what happens in domestic breeding except that a set of traits is randomly selected out of the population to form the new species.
You are ignoring mutations. If the two populations are not interbreeding then different mutations will start to build up in each population which results in divergence over time.
The ToE says that evolution is powered by benefit to survival and reproduction, but in my model no such selective pressures need apply and usually don't.
You are ignoring mutations.

This message is a reply to:
 Message 539 by Faith, posted 06-28-2019 2:42 AM Faith has replied

Replies to this message:
 Message 551 by Faith, posted 06-28-2019 7:07 PM Taq has replied

  
RAZD
Member (Idle past 1655 days)
Posts: 20714
From: the other end of the sidewalk
Joined: 03-14-2004


Message 550 of 785 (856203)
06-28-2019 12:18 PM
Reply to: Message 539 by Faith
06-28-2019 2:42 AM


Re: The genetic loss idée fixe vs reality
Mutation, migration (gene flow), genetic drift, and natural selection as mechanisms of change;
and
The importance of genetic variation; The random nature of genetic drift and the effects of a reduction in genetic variation; How variation, differential reproduction, and heredity result in evolution by natural selection; and
Are not part of my posts in this thread. Please designate source. Not that they are wrong, just want to be clear on what comes from where.
As I was thinking through this list it hit me that Mutation and gene flow ADD to the genetic variability, and must create a scattered effect of phenotypes, and must create a scattered effect of phenotypes. ...
Mutations add to the gene pool, gene flow distributes the gene pool in the breeding population.
... What makes for a homogeneous species, on the other hand, is the subtractive processes of selection. ...
or the spread of new mutations/genes throughout the breeding population, which can occur with a dominant gene, or because selection pressure is low.
... It took me a while to figure out "genetic drift" and now I see it as just one form of species creation by isolating a portion of the population. ...
Not necessarily. It's an arbitrary (stochastic) loss of genetic (gene pool) material because it doesn't make it through breeding, but it doesn't make the species different from before, just reduced in gene pool material. Stochastic processes involve arbitrary deaths that are not related to survival or reproduction (volcanic eruptions, earthquakes, forest fires, floods, etc).
... It isn't a process or a mechanism at all and it's hard to figure out why it's even on the list.
It is a process that affects the gene pool.
I note that the definition now includes "the effects of a reduction in genetic variation" which seems **** it could be an attempt to take into account what I keep arguing. This is new to the definition; it wasn't there when I was coming to my view of reduced genetic variability. AND it's not my view anyway: Calling it "genetic variation"is the clue that it's not the same thing as "genetic variability." "variation is a result; variability is a potential. But this is probably not the place to try to get into this discussion.
Genetic drift may be one of the prime drivers for new species, as lost genetic material is replaced by new material (mutations) that have less competition in being selected, changing the gene pool.
This strikes me as gobbledygook beyond my ability to sort out on short notice, but maybe I can come back to it. "...RESULT in evolution by natural selection" makes no sense whatever. At least it explains that it is the randomness of genetic drift that gets it on the list. The problem with that is, as I was thinking through how species develop from population splits, ALL such ways species get created are random in the wild. It's only in domestic breeding that they aren't random.
Now I'm regretting getting off into all this but I'm going to leave it as a record of how confused the definitions can get, and get back to your post if I can.
Again, that was not my post and it seems you've left out some things. Providing a source to see context would help. For now it just shows how confused you are.
I certainly agree that "evolution in the wild doesn't have to eliminate everything that doesn't fit [some] chosen set of traits" but I never ever suggested that kind of similarity with breeding anyway. I've always said it's a random process. What happens is that a set of traits is randomly selected by the separation of a portion of the parent population to become a daughter population. That random separation of a certain group of individuals forms a new gene pool with new gene frequencies ...
Natural selection is not random, it selects among available traits by what is useful for survival and reproduction.
The separation of the population may be due to stochastic events and it may result in a smaller gene pool, but that isn't necessarily the case.
You can also have a new mutation/trait that allows the species to expand into a new area. Black fur pocket mice for instance, able to inhabit lava fields that are dangerous for tan furred mice.
The larger and more homogeneous the population the more likely the gene pool will be similar.
... That random separation of a certain group of individuals forms a new gene pool with new gene frequencies that when blended together over some number of generations of breeding brings out a distinctively new species from a new group of phenotypes created by the new gene frequencies in sexual recombination for those generations. It's the same process as what happens in domestic breeding except that a set of traits is randomly selected out of the population to form the new species.
You don't get new phenotypes with the same old gene pool or a subset of it.
Here we have another example of how different my model is from yours. The ToE says that evolution is powered by benefit to survival and reproduction, but in my model no such selective pressures need apply and usually don't. ALL IT TAKES TO GET A NEW SPECIES IS THE NEW GENE FREQUENCIES BROUGHT ABOUT BY THE SEPARATION AND ISOLATION OF A PORTION OF THE ORIGINAL POPULATION. That's ALL it takes. No selective pressure at all, no ecological pressure, nothing environmental at all. The genetic rearrangements are the whole thing. There COULD be some input from natural selection but there's no need for it and I don't think it happens much.
Here we have another example of how different my model is from yours. Mine works, yours doesn't. Mine explains all the evidence, yours only explains part of it ... at best, and it ignores the fact that every generation has new mutations that change the gene pool. This means that over time (generations) the gene pool changes and new phenotypes from original genes is no longer possible -- the genes have been replaced or modified. You get new phenotypes with new genes.
Although the ToE was invoked to explain the evolution of the larger head and jaw of the Pod Mrcaru lizards after thirty years in isolation, meaning they were actively adapting to the tougher kind of plant they came to prefer, but there is no hint that there was any absnese of the kind of food they had when they were still part of the parent population, they just came to prefer the tougher food. MY EXPLANTION OF THIS IS THAT their new gene frequencies contained the emphasis on larger head and jaw and that alone brought out that characteristic. Then BECAUSE THEY HAD THAT CHARACTERISTIC, THEN they wree drawn to the tougher kind of food that they could now eat. ...
Yep. Once they had the mutation for larger jaw they were able to take advantage of the opportunity of the tougher plant food. Evolution in response to challenges and opportunities.
At that point you don't WANT change, you WANT preservation. All the changes occurred on the way to establishing the breed.
As I said, mutations allowed the new breed type to exist and then all further mutations were culled. This is why breeding is not a model for evolution: it is a specific type of selection -- it doesn't model natural selection and it doesn't include mutations.
It's true that I don't try enough to answer these basic tenets of evolution which is probably the cause of a lot of miscommunication. I content myself with trying to describe my different model but I see that it has to try to answer all these other objections more than I take into account.
True.
I think what I need to do is try to put together a lengthy article trying to cover the whole shebang since I now think I'm leaving too much out of these discussions. Not something to do at EvC of course.
Be prepared for sharp criticism.
Enjoy

we are limited in our ability to understand
by our ability to understand
RebelAmerican☆Zen☯Deist
... to learn ... to think ... to live ... to laugh ...
to share.


Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click)

This message is a reply to:
 Message 539 by Faith, posted 06-28-2019 2:42 AM Faith has replied

Replies to this message:
 Message 552 by Faith, posted 06-28-2019 7:13 PM RAZD has replied

  
Faith 
Suspended Member (Idle past 1694 days)
Posts: 35298
From: Nevada, USA
Joined: 10-06-2001


Message 551 of 785 (856240)
06-28-2019 7:07 PM
Reply to: Message 549 by Taq
06-28-2019 11:48 AM


Re: The genetic loss idée fixe vs reality
No population is *perfectly* homogeneous but the wildebeests are pretty homogeneous, both the black herd and the blue herd; also buffalo; black bears are pretty homogeneous, also polar bears, grizzly bears etc.; kangaroos are pretty homogeneous, so are the Pod Mrcaru lizards, also most wild species of birds, and fish species etc etc etc. Even so there may be a great deal of genetic diversity in such populations.

This message is a reply to:
 Message 549 by Taq, posted 06-28-2019 11:48 AM Taq has replied

Replies to this message:
 Message 553 by Tanypteryx, posted 06-28-2019 7:58 PM Faith has replied
 Message 595 by Taq, posted 07-01-2019 12:23 PM Faith has not replied

  
Faith 
Suspended Member (Idle past 1694 days)
Posts: 35298
From: Nevada, USA
Joined: 10-06-2001


Message 552 of 785 (856241)
06-28-2019 7:13 PM
Reply to: Message 550 by RAZD
06-28-2019 12:18 PM


Re: The genetic loss idée fixe vs reality
[the processes of evolution I posted] Are not part of my posts in this thread. Please designate source. Not that they are wrong, just want to be clear on what comes from where.
I copied them off the Google page on "processes of evolution." They are from the Cal Berkeley website on evolution.

This message is a reply to:
 Message 550 by RAZD, posted 06-28-2019 12:18 PM RAZD has replied

Replies to this message:
 Message 557 by RAZD, posted 06-29-2019 9:02 AM Faith has replied

  
Tanypteryx
Member
Posts: 4597
From: Oregon, USA
Joined: 08-27-2006
Member Rating: 9.9


Message 553 of 785 (856242)
06-28-2019 7:58 PM
Reply to: Message 551 by Faith
06-28-2019 7:07 PM


Re: The genetic loss idée fixe vs reality
No population is *perfectly* homogeneous but the wildebeests are pretty homogeneous, both the black herd and the blue herd; also buffalo; black bears are pretty homogeneous, also polar bears, grizzly bears etc.; kangaroos are pretty homogeneous, so are the Pod Mrcaru lizards, also most wild species of birds, and fish species etc etc etc.
Pretty homogeneous is hardly precise or scientific. I bet that you cannot find a single biologist specializing in the study of any of the organisms you mention that will agree with you. How many individuals of these creatures have you studied to make this determination?
Even so there may be a great deal of genetic diversity in such populations.
Of course. Most of the variable features in the members of a species are not visible characters, but rather variations in metabolic processes and internal structure.
You, sitting in front of your computer are hardly likely to notice the range of visible variation in the few photos of individual creatures you see on the screen. Polar bears are all white is about as far as you can go.

What if Eleanor Roosevelt had wings? -- Monty Python
One important characteristic of a theory is that is has survived repeated attempts to falsify it. Contrary to your understanding, all available evidence confirms it. --Subbie
If evolution is shown to be false, it will be at the hands of things that are true, not made up. --percy
The reason that we have the scientific method is because common sense isn't reliable. -- Taq

This message is a reply to:
 Message 551 by Faith, posted 06-28-2019 7:07 PM Faith has replied

Replies to this message:
 Message 554 by Faith, posted 06-28-2019 11:04 PM Tanypteryx has not replied

  
Faith 
Suspended Member (Idle past 1694 days)
Posts: 35298
From: Nevada, USA
Joined: 10-06-2001


Message 554 of 785 (856252)
06-28-2019 11:04 PM
Reply to: Message 553 by Tanypteryx
06-28-2019 7:58 PM


Re: The genetic loss idée fixe vs reality
I'm talking about their obvious appearance. I recall that in RAZD's Message 424 or the one before it, he describes the point at which a species becomes a species in terms that imply arrival at homogeneity, which has always been my criterion too. I responded that I'd discussed that myself. In my scenario it's the point at which all the new phenotypes in a new population have blended together using all the gene frequencies possessed by the original founders, through whatever number of generations it takes to bring that about.
Before that it starts with the founders all looking llke the homogeneous parent population. Then there is a phase where there is a motley collection of different phenotypes scattered through the population, being brought out by the new set of gene frequencies. After a few more generations they form their own new overall homogeneous appearance distinct from the original parent population.
Each individual has its own unique genome nevertheless, so that if some of them eventually form a new isolated population themselves they will contribute a unique set of gene frequencies to it that when reproductively blended together over some generations will produce yet another homogeneous population with characteristics disctinct from all the others.
Edited by Faith, : No reason given.
Edited by Faith, : No reason given.
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 553 by Tanypteryx, posted 06-28-2019 7:58 PM Tanypteryx has not replied

Replies to this message:
 Message 563 by Percy, posted 06-29-2019 3:24 PM Faith has not replied

  
Faith 
Suspended Member (Idle past 1694 days)
Posts: 35298
From: Nevada, USA
Joined: 10-06-2001


Message 555 of 785 (856261)
06-29-2019 2:03 AM
Reply to: Message 544 by herebedragons
06-28-2019 9:53 AM


Re: The genetic loss idée fixe vs reality
Good grief, HBD. I'm about to get off the computer and go to bed but I read through a few of your paragraphs, down to where you say all this diversity you see proves my model wrong and I have to answer: don't you know I'm not talking about PHENOTYPIC DIVERSITY having to decrease? The whole point is that phenotypes proliferate while GENETIC DIVERSITY gets reduced. I have to sleep so I'm not going to try to deal with the rest until tomorrow.

This message is a reply to:
 Message 544 by herebedragons, posted 06-28-2019 9:53 AM herebedragons has replied

Replies to this message:
 Message 558 by herebedragons, posted 06-29-2019 11:56 AM Faith has replied

  
Newer Topic | Older Topic
Jump to:


Copyright 2001-2023 by EvC Forum, All Rights Reserved

™ Version 4.2
Innovative software from Qwixotic © 2024