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Author Topic:   The End of Evolution By Means of Natural Selection
misha
Member (Idle past 4657 days)
Posts: 69
From: Atlanta
Joined: 02-04-2010


Message 197 of 851 (554107)
04-06-2010 1:17 PM


There is more than one way to skin a cat. . .
Along with the issues brought up by others concerning the frequency of mutations and their contributions to diversity, I find that Faith is oversimplifying possible solutions to selective pressures. A main crux of her argument is that natural selection will pare a population down to a single allele.
This is not the case. Genes are not mutually exclusive, changes to one gene can result in changes to more than one trait. In order to see this more clearly we can look at the afformentioned frog tongues.
Long tongues may be beneficial for catching some food sources but this does not mean that they are the best tongue type for catching all prey. A longer tongue would in turn result in more tongue weight. The increase in tongue weight without an equal increase in expellatory forces would result in a slower tongue. Although there will be an ideal tongue length vs tongue speed in this 2 variable set of equations, that ideal would be based on the frog's prey size, prey speed and average striking distange from prey. These factors could result in multiple solutions for the frog.
A situation like this could easily result in speciation or just increased diversity.

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 Message 199 by Faith, posted 04-06-2010 3:33 PM misha has not replied

  
misha
Member (Idle past 4657 days)
Posts: 69
From: Atlanta
Joined: 02-04-2010


Message 486 of 851 (556844)
04-21-2010 10:22 AM
Reply to: Message 472 by Peepul
04-21-2010 5:21 AM


Re: Mutations Revisited 2
Peepul writes:
I've been thinking about this in the context of dogs. I suspect (though I don't know) that the massive size variation in dogs is brought about by assortment of alleles rather than mutations. The biggest dogs and the smallest dogs are reproductively isolated from each other - they cannot mate and the small dogs could not bring a mixed puppy to term. Something similar in the wild would generate multiple species.
I see what you're saying. But I think you're wrong in assuming that large dogs and small dogs can't mate. Yes, it is a physical barrier for a large male dog to impregnate a small female dog. And it is a physical barrier for a small female dog to carry a large dog offspring to term. But if you flip the genders reproduction is easily possible. Other than the fact that the large female dog would have to be laying down, is there any reason why a small male dog physically could not impregnate her? Is there any reason why the large female could not carry a small offspring to term?
My wife's old roommate had a rotweiller/dacshund mix. Rotweiller mother, dacshund father. The smaller father had minimal issues impregnating the larger mother and the larger mother had minimal issues carrying the pups to term. The dog grew to be larger than a dacshund but smaller than a rotweiller, a hybrid. A male dog from the litter could easily impregnate another female rotweiller or a female dachshund and then you would have fourth and fifth size variants.
Unless there is a mechanism that would create barriers for a large mother/small father combination then I don't think size could be the lone cause of a speciation event.

This message is a reply to:
 Message 472 by Peepul, posted 04-21-2010 5:21 AM Peepul has replied

Replies to this message:
 Message 517 by Peepul, posted 04-22-2010 3:54 AM misha has replied

  
misha
Member (Idle past 4657 days)
Posts: 69
From: Atlanta
Joined: 02-04-2010


Message 520 of 851 (557034)
04-22-2010 9:36 AM
Reply to: Message 517 by Peepul
04-22-2010 3:54 AM


Re: Mutations Revisited 2
Peepul writes:
Do you think the same is true of the smallest and largest dogs, eg chihuahua and great dane? There I can see the logistics being a problem!
I'm not sure. I don't breed dogs for a living. However, logistically I think the main issue would be ejaculation of the male chihuahua into the female dane. This is where I could see an issue. Is the male chihuahua's phallus large enough to make enough contact with the vaginal wall of the dane in order to induce the ejaculation?
Sorry, didn't mean to be so graphic with that. But i can't think of another way to explain it scientifically.

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Replies to this message:
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 Message 523 by Huntard, posted 04-22-2010 10:13 AM misha has not replied

  
misha
Member (Idle past 4657 days)
Posts: 69
From: Atlanta
Joined: 02-04-2010


(1)
Message 535 of 851 (557070)
04-22-2010 1:24 PM
Reply to: Message 529 by Faith
04-22-2010 12:28 PM


Re: Mutations Revisited 2 - super-pac magic animals
WK writes:
She is suggesting that the initial ancestral organisms, in a flood scenario presumably the breeding pair Noah selected, had very high ploidy compared to modern organisms, and therefore had multiple alleles for each gene. There are some modern animals with high ploidy, particularly the various species of Xenopus which can be up to dodecaploid having 12 sets of chromosomes, but even in this case that would give you a maximum of 24 alleles for every gene.
However, through this Faith is also suggesting that almost every vertebrate and more specifically every known mammal except for one rare Argentinian rat (tetraploid) has undergone the a level of "ploid" reduction resulting in the almost unanimous diploid scenario we see currently. However, during this decrease her humans would have not undergone any speciation events where as every other animal would have. Also no more "ploid" reduction would be available in the future unless these future creatures are uniploid/asexual.
The sheer mental gymnastics required to adhere to such an illogical and unfactual stance is ridiculous.

This message is a reply to:
 Message 529 by Faith, posted 04-22-2010 12:28 PM Faith has replied

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 Message 539 by Faith, posted 04-22-2010 3:28 PM misha has not replied

  
misha
Member (Idle past 4657 days)
Posts: 69
From: Atlanta
Joined: 02-04-2010


Message 708 of 851 (558290)
04-30-2010 2:56 PM
Reply to: Message 704 by Faith
04-30-2010 1:58 PM


Re: hypothetical beneficial mutations
Faith writes:
It's illogical. To call an error a mere neutral "change" is some kind of deception.
Its not deception at all. Replication "errors" ARE just changes resulting in imperfect copies. It is merely human point of view that could consider them an error. The beneficiality, neutrality or harmfulness of these changes is only partially due to the previous state of the DNA. The result of the change has more to do with the environment of the organism than its previous state.
You seem to be under the delirious impression that DNA has a set perfect state for each organism and that any change from this perfect state is automatically deleterious.

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 Message 704 by Faith, posted 04-30-2010 1:58 PM Faith has not replied

  
misha
Member (Idle past 4657 days)
Posts: 69
From: Atlanta
Joined: 02-04-2010


Message 727 of 851 (558632)
05-03-2010 10:53 AM
Reply to: Message 725 by Straggler
05-03-2010 9:54 AM


Re: Making Sense To Faith
Straggler writes:
You seem very hung up on the term "error". It is better thought of as an imperfect copy. An imperfect copy that can be "better", "worse" or neutral in terms of the effect it has in the environment in which it occurs.
I would even restrain from using the term "imperfect copy" because it implies that the parent copy was perfect.
I would prefer "inexact copy" because exactness does not imply perfection. Someone, as Faith has shown, can be exactly wrong. An inexact copy can be preferable as compared to the original as long as that inexact copy is more beneficial.

This message is a reply to:
 Message 725 by Straggler, posted 05-03-2010 9:54 AM Straggler has replied

Replies to this message:
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