Register | Sign In


Understanding through Discussion


EvC Forum active members: 65 (9162 total)
5 online now:
Newest Member: popoi
Post Volume: Total: 915,817 Year: 3,074/9,624 Month: 919/1,588 Week: 102/223 Day: 13/17 Hour: 0/1


Thread  Details

Email This Thread
Newer Topic | Older Topic
  
Author Topic:   Evolution Requires Reduction in Genetic Diversity
Dr Adequate
Member (Idle past 284 days)
Posts: 16113
Joined: 07-20-2006


(6)
Message 267 of 1034 (692418)
03-02-2013 9:04 PM


Stuff That Actually Happens
It is instructive to look at the actual formation of a new breed. Fortunately we can do this: there are breeds of animal which are younger than I am. One such is the attractive cat breed known as the American Curl because of its whimsical ears and country of origin.
The career of the American Curl was launched in 1981 when a longhaired black cat with curly ears turned up on the doorstep of Grace Ruga, a citizen of Lakewood, California. Ruga named that cat Shulamith, and when Shulamith produced a litter of kittens two of which displayed curled ears, she began to suspect that she had a new breed on her hands. Members of the "cat fancy" confirmed that this was indeed a novel trait, and the American Curl was accepted as an official breed by the International Cat Association in 1987.
Research showed that the new phenotype was caused by a single autosomal dominant allele (see Robinson, 1989. The American Curl Cat, Journal of Heredity 80 (6): 474—475.) This means that the allele can't have existed much before 1981, because if it had, its carriers would all have had curly ears, and cat affectionados would have noticed all the curly-eared cats prancing around.
All American Curls are descended from Shulamith, but obviously not only from Shulamith because of cats not being capable of vegetative cloning. She and her kittens had to be outbred with non-Curl cats, the carriers of the Curl allele being retained for the breeding program; to prevent the inbreeding problems that plague many pedigree breeds, repeated outbreeding with non-Curls was carried on as a deliberate policy until 2010. Consequently, Curls are now available with short hair as well as long hair, and in every known color and pattern of fur.
To summarize:
* We know that the breed originated with a de novo mutation sometime around 1981.
* This mutation increased the genetic diversity of the cat species to the tune of one allele.
* The genetic diversity of the Curl breed increased continually between 1981 and 2010, and is clearly now much greater than when Shulamith was its sole representative.
All this is, of course, the exact opposite of what Faith thinks ought to happen. But reality seems singularly uninterested in her opinions.

Replies to this message:
 Message 270 by Faith, posted 03-02-2013 9:38 PM Dr Adequate has replied

  
Dr Adequate
Member (Idle past 284 days)
Posts: 16113
Joined: 07-20-2006


(3)
Message 272 of 1034 (692426)
03-02-2013 11:15 PM
Reply to: Message 270 by Faith
03-02-2013 9:38 PM


Re: Stuff That Actually Happens
The American Curl may be unique in being developed from a mutation ...
Why would one think that?
Note that your personal preference is not actually a reason.
Heck, I can think of another case involving the ears of cats. Ever heard of the Scottish Fold, Faith? It's named for ... you guessed it, its whimsical ears and its country of origin. The founding member of the breed was found at a farm near Coupar Angus in Perthshire, Scotland, in 1961, and named Susie. All Scottish Folds are descended from Susie. Can you guess what sort of gene is responsible for the trait? If you said "autosomal dominant", take one point. Is any of this sounding familiar? Dj vu creeping in yet?
But once breeding becomes a matter of inbreeding ONLY with American Curls then you'll see the loss of genetic diversity I'm talking about as alleles for all the other types of ears will be reduced and even ultimately disappear from the gene pool altogether.
And yet it will still have more genetic diversity than it did when the breed had only one member.
But it's still possible in my mind that even this very rare characteristic was not a mutation but a very rare combination of existing alleles for perhaps more than one gene. Very rare. Yes, possible. So that you don't really "know" that it was a mutation.
I do in fact, because I know that that's what actual studies show, and I also know that the evidence trumps whatever's going on in your mind.
If it was a combination of alleles, then it would behave rather like a recessive. You could outbreed Curls with non-Curls, some of the non-Curls in the resulting generation would get one of the Curl alleles and some would get the other, and then you could recombine the alleles by breeding that generation together, and get some Curls back. But in fact the Curl breeds exactly as though the trait was caused by a single autosomal dominant allele. 'Cos it is.
Sorry you find reality so much not to your liking.
I find it highly congenial. That's why I wrote a post about real things and you responded by writing about imaginary things in your head.

This message is a reply to:
 Message 270 by Faith, posted 03-02-2013 9:38 PM Faith has replied

Replies to this message:
 Message 280 by Faith, posted 03-03-2013 3:00 PM Dr Adequate has replied

  
Dr Adequate
Member (Idle past 284 days)
Posts: 16113
Joined: 07-20-2006


(2)
Message 282 of 1034 (692465)
03-03-2013 4:15 PM
Reply to: Message 280 by Faith
03-03-2013 3:00 PM


Re: Stuff That Actually Happens
GOLLY GEE, TWO WHOLE CASES!
That's two more than you've produced in favor of your ideas.
An epidemic of mutation-based breeds!
Indeed there are. For example, let's talk about the American Wirehair, so named because of the country of its origin and the resemblance of its hair to steel wool. The first American was born to two ordinary American Shorthairs named Bootsie and Fluffy on Council Rock Farm in Verona NY in 1966, and was the only one in his litter to exhibit the trait. Local cat-breeder Joan O'Shea recognized the kitten as a new variety, bought him for $50 and called him Council Rock Farm Adam of Hi-Fi, because ... no, I don't know. It's the "of Hi-Fi" bit that really puzzles me.
All American Wirehairs today are descended from Adam, as I shall call him from now on. Adam was outbred with ordinary American Shorthairs to establish the breed. For this reason, although Adam was red and white, American Wirehairs now come in every color, and the breed is clearly more genetically diverse than when it consisted only of Adam.
The wirehair allele is, guess what? ... autosomal dominant. Therefore similar remarks apply to its novelty as apply to the Americal Curl and the Scottish Fold.
Now, shall we talk about the LaPerm breed, noted for its ringlet coat? It originated with a single kitten called Curly, born in 1982 on the Oregon cherry farm of Linda and Dick Koehl. All LaPerm cats are descended from Curly; outbreeding was performed with a number of different pedigree and non-pedigree cats to increase the diversity of the breed. The LaPerm gene is autosomal dominant ...
Now shall we talk about the Selkirk Rex and the Munchkin ... ? Actually, there's no need, the only differences are the dates, the locations, the names of the cat owners, the names of the cats, and the traits.
---
Are you beginning to see a pattern here, Faith? When we have records of the origin of a new breed, it turns out to have resulted from the recognition of a novel mutation in a single individual, followed (as a matter of biological necessity) by outbreeding which logically entails increasing the diversity of the breed up from the point at which it had only one member.
None of the breeds we've looked at here can have been produced by whittling away at pre-existing genes, because they are all caused by autosomal dominant alleles; if the curl, fold, wirehair and LaPerm alleles had always existed, then so would Curl, Fold, Wirehair and LaPerm cats.
And again, you don't KNOW if this was a mutation.
Yes I do. For reasons which have been explained to you. If you didn't understand the reasoning, that means that you don't know that it was a mutation. I, on the other hand, do.
Edited by Dr Adequate, : No reason given.
Edited by Dr Adequate, : No reason given.

This message is a reply to:
 Message 280 by Faith, posted 03-03-2013 3:00 PM Faith has replied

Replies to this message:
 Message 283 by Faith, posted 03-03-2013 4:37 PM Dr Adequate has replied

  
Dr Adequate
Member (Idle past 284 days)
Posts: 16113
Joined: 07-20-2006


(1)
Message 287 of 1034 (692474)
03-03-2013 5:37 PM
Reply to: Message 283 by Faith
03-03-2013 4:37 PM


Re: Stuff That Actually Happens
Well, at least recognition of a novel trait in a single individual, but as for its source being mutation, no you don't know that. You don't know but what thirty years previously the same trait showed up in a remote area where it soon got interbred back into oblivion.
Possibly it did. But since it's autosomal dominant, it then requires a new mutation to bring it back from oblivion. If there had always been the genes, then there would always have been these types of cats.
Which of course I not only acknowledged but elaborated in my own post.
Good. So, here we have the production of new breeds by a process that increases the genetic diversity of the breed. Are we done here?
I didn't say they were. Clearly they emerged as single novel traits in individuals (but this in itself doesn't have to be the result of a mutation but can be the result of the simple absence of of the other genetic combinations for other versions of the same trait occurring through normal sexual recombination)
But we know the traits are autosomal dominant.
And for some reason the god Mutation favors autosomal dominant alleles and likes to repeat them for the same trait from time to time?
That was an odd thing to say. What is your point?
And PERHAPS you are right. But I have my doubts nevertheless. As I said, I understand that even dominant alleles can be suppressed in the phenotype and only show up in particular combinations of alleles for more than one gene.
But I've explained why that's not the case. If it required a combination of alleles, then it would behave (superficially) as though it was recessive, not dominant.
Edited by Dr Adequate, : No reason given.

This message is a reply to:
 Message 283 by Faith, posted 03-03-2013 4:37 PM Faith has not replied

  
Dr Adequate
Member (Idle past 284 days)
Posts: 16113
Joined: 07-20-2006


Message 289 of 1034 (692481)
03-03-2013 8:37 PM
Reply to: Message 288 by Faith
03-03-2013 7:10 PM


Re: Questions
Because you eventually run out of genetic possibilities ...
Sure, eventually but not before the awesome diversity of the morganucodons has been whittled down to the nondiversity displayed by such relatively homogeneous creatures as the elephant, the giraffe, the weasel, the whale, the bat ...
Clearly what happened here is that some lineages descending from the morganucodons lost the genes for not being elephants, others lost the genes for not being bats, and so forth, until from the rich genetic diversity of the morganucodons, we ended up with the genetically impoverished wasteland of the modern Mammalia.
Obviously after so much diversity has been lost, all that this process can produce nowadays is the wide range of nondiversity seen in all the various breeds of dogs, cats, pigeons, etc. But it is clear that any amount of diversity could have been destroyed in the past, even narrowing down diversity from the genetic abundance of a single ancestral species to the lack of diversity displayed by the many families of modern mammals.

This message is a reply to:
 Message 288 by Faith, posted 03-03-2013 7:10 PM Faith has replied

Replies to this message:
 Message 291 by Faith, posted 03-03-2013 9:29 PM Dr Adequate has replied

  
Dr Adequate
Member (Idle past 284 days)
Posts: 16113
Joined: 07-20-2006


(2)
Message 292 of 1034 (692485)
03-03-2013 10:04 PM
Reply to: Message 291 by Faith
03-03-2013 9:29 PM


Re: Questions
Whew! Must say that the imaginative fantastical wishfulness of the evolutionist takes the breath away. How could one fight such castles in the air? There are always many more where those came from.
It's your theory of evolution I'm talking about here. The one I adhere to is somewhat different. The castle in the air is of your building, I'm just asking you to tell us more about the details of its architecture.
Well, back to reality for a moment here. What really happens is that the genetic diversity that gets eaten up is the diversity that belongs to the particular Kind ...
Yeah, in this case the mammal Kind.
You are always only getting dogs from dogs (and here I do think of the wolf as just the original Dog anyway), cats from cats, elephants from elephants and so on.
Well, now you are. But this is only because so much genetic diversity has already been lost in the process of producing the various families, genera, and species of animals.

This message is a reply to:
 Message 291 by Faith, posted 03-03-2013 9:29 PM Faith has not replied

  
Dr Adequate
Member (Idle past 284 days)
Posts: 16113
Joined: 07-20-2006


(1)
Message 302 of 1034 (692546)
03-04-2013 6:36 PM
Reply to: Message 299 by nwr
03-04-2013 6:06 PM


Re: Faith is done with this thread ???
She's still pretending that the layers in the Grand Canyon are "tabletop flat" too. I just hope she never takes up carpentry.

This message is a reply to:
 Message 299 by nwr, posted 03-04-2013 6:06 PM nwr has seen this message but not replied

  
Dr Adequate
Member (Idle past 284 days)
Posts: 16113
Joined: 07-20-2006


(1)
Message 317 of 1034 (692734)
03-06-2013 10:07 PM
Reply to: Message 315 by NoNukes
03-06-2013 8:13 PM


Re: Jeer bait
I don't know what work Faith could have been doing with her proposal for the last decade ...
Well she could have spent five minutes finding out that she was wrong, and the other 5,259,485 minutes doing something that wasn't stupid.

This message is a reply to:
 Message 315 by NoNukes, posted 03-06-2013 8:13 PM NoNukes has seen this message but not replied

  
Dr Adequate
Member (Idle past 284 days)
Posts: 16113
Joined: 07-20-2006


Message 345 of 1034 (726300)
05-08-2014 2:45 AM
Reply to: Message 41 by Dr Adequate
02-25-2013 11:42 AM


Re: Walking Requires Staying In The Same Place
As walkists admit (such as the notoriously pro-walkist Wikipedia): "In humans and other bipeds, walking is generally distinguished from running in that only one foot at a time leaves contact with the ground and there is a period of double-support."
This means that walking requires leaving the right foot fixed in one place. Because I am not very bright, I shall now insist that this means that walking requires the right foot must be fixed in one place all the time. This means that someone walking cannot move from the spot, but can only turn around in circles.
On this principle, I shall assert that micro-walking (for example to the shops and back) is perfectly possible, even though this flatly contradicts what I've just said. I'm not big on logical consistency. However, macro-walking, for example hiking the Appalachian trail, is clearly impossible, because you could not do that by merely revolving on the spot, which as I've explained is all a person can ever do when walking.
Now, I know that some of you will point out that walking also involves moving the right foot, and that micro-walking, the existence of which I admit, definitely involves moving the right foot and indeed allows one to travel from place to place. How do I know that you will say that? Because it's what you said last time I raised this damnfool argument, and the time before that.
However, I'm sure I can ignore these obvious facts for the rest of this thread, and also for the duration of the other thread I'll start in another couple of months to say exactly the same thing. Instead I shall repeatedly assert that the process of walking requires the right foot to remain stationary, focusing obsessively on this one aspect of the process of walking and ignoring everything else about it, as though this somehow proved my point.
What I lack in intelligence, I make up for in the tenacity with which I can maintain an argument the deep unfathomable stupidity of which is completely obvious to every single person I try it out on.
What makes this analogy so apposite is that Faith is herself going round in tiny circles and making no progress.

This message is a reply to:
 Message 41 by Dr Adequate, posted 02-25-2013 11:42 AM Dr Adequate has not replied

Replies to this message:
 Message 349 by Faith, posted 05-08-2014 5:46 AM Dr Adequate has not replied

  
Dr Adequate
Member (Idle past 284 days)
Posts: 16113
Joined: 07-20-2006


Message 371 of 1034 (727627)
05-19-2014 12:59 PM
Reply to: Message 370 by Faith
05-19-2014 12:28 PM


Re: No 'new functions'
I don't believe mutations contribute anything at all to normal variation/microevolution, except possibly the very rare fluke when a mistake in replication happens to reproduce a sequence that revives a formerly lost function. But normal variation is the result of normal sexual recombination of built-in genetic possibilities. I know it's hard to think along these lines if you are used to thinking in terms of mutations, but this is the way it used to be understood and they were right.
But it must have been brought to your attention --- repeatedly --- that direct observation shows this to be untrue.

This message is a reply to:
 Message 370 by Faith, posted 05-19-2014 12:28 PM Faith has replied

Replies to this message:
 Message 372 by Faith, posted 05-19-2014 1:14 PM Dr Adequate has replied

  
Dr Adequate
Member (Idle past 284 days)
Posts: 16113
Joined: 07-20-2006


Message 373 of 1034 (727638)
05-19-2014 1:48 PM
Reply to: Message 372 by Faith
05-19-2014 1:14 PM


Re: No 'new functions'
So if you've seen it, it's been shown rather than "ASSERTED and CLAIMED" and if you've seen "three or four", then one would suffice to overturn your general claim.
What you mean by "iffy" is known only to yourself and, if he exists, the god whom you claim to serve.

This message is a reply to:
 Message 372 by Faith, posted 05-19-2014 1:14 PM Faith has not replied

  
Dr Adequate
Member (Idle past 284 days)
Posts: 16113
Joined: 07-20-2006


(1)
Message 383 of 1034 (757489)
05-09-2015 5:42 PM
Reply to: Message 40 by NoNukes
02-25-2013 11:40 AM


Re: Ring Species -- Greenish Warbler -- and Genetic Diversity
Finally, what's the difference between this thread and the 670+ message thread from three years ago.
And indeed between that thread and this thread and the one we're doing now.
Edited by Dr Adequate, : No reason given.

This message is a reply to:
 Message 40 by NoNukes, posted 02-25-2013 11:40 AM NoNukes has not replied

  
Dr Adequate
Member (Idle past 284 days)
Posts: 16113
Joined: 07-20-2006


(2)
Message 391 of 1034 (757710)
05-12-2015 11:15 AM
Reply to: Message 385 by Faith
05-11-2015 7:16 PM


Re: No 'new functions'
Again I don't see what this has to do with anything I've said. But as far as blending goes, allleles don't blend but apparently the effect of so many genes for variations in skin color pretty much amounts to a blending of the traits themselves. You get degrees of lightness and darkness as well as combinations of shades of yellow, red and blue.
This is why I keep rubbing your nose in autosomal dominant genes.
Now, where we'd got up to on the other thread is that you admit that these genes can arise by mutation, and that at least where we have more than five alleles per locus, that must have arisen by mutation too.
Also, we've observed this happening, as in my six examples of cat breeds.
So why are we not done here? What do you suppose is left of your argument that you go on arguing?
Edited by Dr Adequate, : No reason given.

This message is a reply to:
 Message 385 by Faith, posted 05-11-2015 7:16 PM Faith has replied

Replies to this message:
 Message 393 by Faith, posted 05-12-2015 6:59 PM Dr Adequate has replied

  
Dr Adequate
Member (Idle past 284 days)
Posts: 16113
Joined: 07-20-2006


Message 394 of 1034 (757732)
05-12-2015 7:33 PM
Reply to: Message 393 by Faith
05-12-2015 6:59 PM


Re: genetic diversity
Why have you said that a bazillion times?
Obviously you need some genetic diversity to have evolution at all. If you had a population of exact clones, no evolution could take place --- until a mutation arose to provide some diversity.
So it seems like the title of this thread should be Evolution Requires the Existence Of Genetic Diversity.

This message is a reply to:
 Message 393 by Faith, posted 05-12-2015 6:59 PM Faith has not replied

  
Dr Adequate
Member (Idle past 284 days)
Posts: 16113
Joined: 07-20-2006


Message 410 of 1034 (757785)
05-13-2015 6:48 PM
Reply to: Message 408 by Faith
05-13-2015 12:08 PM


Re: genetic diversity
Apparently breeding can result in speciation. At least there is one known instance ...
Interesting point. Now, looking at the great variety of domestic sheep ...
... would we really say that O. aries has less diversity than O. orientalis?

This message is a reply to:
 Message 408 by Faith, posted 05-13-2015 12:08 PM Faith has replied

Replies to this message:
 Message 414 by RAZD, posted 05-14-2015 10:28 AM Dr Adequate has not replied
 Message 415 by Denisova, posted 05-14-2015 12:13 PM Dr Adequate has not replied
 Message 418 by Faith, posted 05-14-2015 2:03 PM Dr Adequate 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