Register | Sign In


Understanding through Discussion


EvC Forum active members: 61 (9209 total)
3 online now:
Newest Member: The Rutificador chile
Post Volume: Total: 919,507 Year: 6,764/9,624 Month: 104/238 Week: 21/83 Day: 4/0 Hour: 0/0


Thread  Details

Email This Thread
Newer Topic | Older Topic
  
Author Topic:   The End of Evolution By Means of Natural Selection
subbie
Member (Idle past 1513 days)
Posts: 3509
Joined: 02-26-2006


Message 6 of 851 (551973)
03-25-2010 3:02 PM
Reply to: Message 1 by Faith
03-25-2010 1:07 PM


You are ignoring a key aspect of evolutionary diversification; reproductive isolation.
You are correct that if one trait becomes so dominant in a population that it drives competing traits out of existence, that would result in a decrease in variability in that population. What you don't address is the fact that there are still other populations that possess the "eliminated" traits. To illustrate this, let me expand on the Wiki example you use.
Let's say we take a relatively homogeneous population and separate it into two jars, and keep track of the pink and blue alleles. It's entirely conceivable that either the pink or the blue might disappear from one population over time through nonselective processes. It's even possible that the pink might disappear from one and the blue from the other. However, since these populations were reproductively isolated from one another, overall there has been no total loss
While separating the populations into two jars is an artificial isolation, this type of isolation happens all the time in the real world. It is this isolation that creates different species. (Well, not entirely true, as speciation can occur over time as well, but that's not really relevant to this discussion. I mention it only so someone else doesn't come in and point out the error.)
I doubt that few here would disagree that from, time to time, some traits will disappear from some populations, and as a result, the total variability in that population is reduced. However that is not nearly the same thing as saying that evolution "inevitably work[s] to reduce the needed genetic variability."

Ridicule is the only weapon which can be used against unintelligible propositions. Ideas must be distinct before reason can act upon them; and no man ever had a distinct idea of the trinity. It is the mere Abracadabra of the mountebanks calling themselves the priests of Jesus. -- Thomas Jefferson
For we know that our patchwork heritage is a strength, not a weakness. We are a nation of Christians and Muslims, Jews and Hindus -- and non-believers. -- Barack Obama
We see monsters where science shows us windmills. -- Phat

This message is a reply to:
 Message 1 by Faith, posted 03-25-2010 1:07 PM Faith has replied

Replies to this message:
 Message 15 by Faith, posted 03-25-2010 4:45 PM subbie has replied

  
subbie
Member (Idle past 1513 days)
Posts: 3509
Joined: 02-26-2006


Message 12 of 851 (551984)
03-25-2010 4:11 PM
Reply to: Message 9 by Faith
03-25-2010 3:58 PM


Consider the dog example while we're at it. Every breed of dog MUST show reduced genetic variability compared to its population of origin because if you want it big you're going to have to eliminate everything that tends to smallness, if you want it good natured you have to eliminate everything that breeds for ferocity, and so on
This is only true if the "first dog" had all possible dog genetic information, and subsequent dogs were created by taking out all the stuff that wasn't necessary for that breed of dog. This idea is ridiculous.

Ridicule is the only weapon which can be used against unintelligible propositions. Ideas must be distinct before reason can act upon them; and no man ever had a distinct idea of the trinity. It is the mere Abracadabra of the mountebanks calling themselves the priests of Jesus. -- Thomas Jefferson
For we know that our patchwork heritage is a strength, not a weakness. We are a nation of Christians and Muslims, Jews and Hindus -- and non-believers. -- Barack Obama
We see monsters where science shows us windmills. -- Phat

This message is a reply to:
 Message 9 by Faith, posted 03-25-2010 3:58 PM Faith has replied

Replies to this message:
 Message 33 by Faith, posted 03-26-2010 2:09 AM subbie has seen this message but not replied

  
subbie
Member (Idle past 1513 days)
Posts: 3509
Joined: 02-26-2006


Message 16 of 851 (551991)
03-25-2010 5:01 PM
Reply to: Message 15 by Faith
03-25-2010 4:45 PM


Re: (Subbie) Am I ignoring reproductive isolation?
Faith writes:
The point I'm making is that WHEREVER EVOLUTION IS GOING ON, THAT'S WHERE you'll have a reduction in genetic diversity, and that is completely at odds with the theory of evolution.
This is simply not true. As an example, let's discuss Darwin's Finches, 15 different species of tanagers that Darwin found on the Galapagos islands. The most important difference among the various species is the size and shape of their beaks. These differences did not come about by the elimination of alleles, but by changes in alleles in different populations, resulting in different species. Thus, in this example, evolution resulted in an increase in genetic diversity. In fact, this sort of increase in genetic diversity is what is most commonly seen in speciation events.

Ridicule is the only weapon which can be used against unintelligible propositions. Ideas must be distinct before reason can act upon them; and no man ever had a distinct idea of the trinity. It is the mere Abracadabra of the mountebanks calling themselves the priests of Jesus. -- Thomas Jefferson
For we know that our patchwork heritage is a strength, not a weakness. We are a nation of Christians and Muslims, Jews and Hindus -- and non-believers. -- Barack Obama
We see monsters where science shows us windmills. -- Phat

This message is a reply to:
 Message 15 by Faith, posted 03-25-2010 4:45 PM Faith has replied

Replies to this message:
 Message 41 by Faith, posted 03-26-2010 3:10 AM subbie has replied

  
subbie
Member (Idle past 1513 days)
Posts: 3509
Joined: 02-26-2006


Message 64 of 851 (552168)
03-27-2010 1:38 AM
Reply to: Message 41 by Faith
03-26-2010 3:10 AM


Re: (Subbie) Am I ignoring reproductive isolation?
Faith writes:
If the alleles for different kinds of beaks were not eliminated you would not have this new species.
But this does not eliminate the alleles from the other species of finches, which still exist. Thus, an increase in the total variety.
A beak type got selected for its usefulness with a particular kind of function, and that got passed on and came to characterize a whole population because the alleles for the other beak types were eliminated from the reproductive pool.
Given that Darwin himself collected examples of the different species, this is obviously not what happened. The different beak types continue to exist and variety increases.
It's not exactly that there were "changes in alleles"
Actually, despite your wishes to the contrary, it is exactly like there were changes in alleles.
The principle I'm hammering away at does hold up you see.
It doesn't, but I'm quite confident that you don't see, and never will.

Ridicule is the only weapon which can be used against unintelligible propositions. Ideas must be distinct before reason can act upon them; and no man ever had a distinct idea of the trinity. It is the mere Abracadabra of the mountebanks calling themselves the priests of Jesus. -- Thomas Jefferson
For we know that our patchwork heritage is a strength, not a weakness. We are a nation of Christians and Muslims, Jews and Hindus -- and non-believers. -- Barack Obama
We see monsters where science shows us windmills. -- Phat

This message is a reply to:
 Message 41 by Faith, posted 03-26-2010 3:10 AM Faith has replied

Replies to this message:
 Message 67 by Faith, posted 03-27-2010 1:46 AM subbie has not replied

  
subbie
Member (Idle past 1513 days)
Posts: 3509
Joined: 02-26-2006


Message 127 of 851 (552396)
03-28-2010 5:00 PM
Reply to: Message 124 by Faith
03-28-2010 2:54 PM


Re: ANOTHER MID-THREAD RECON
7) Do you agree that the end goal of evolution is speciation or is evolution simply any change at all whether it ever leads to speciation or not?
Evolution is descent with modification. It may result in speciation, it may not.
Most importantly, evolution has no end goal. There is no result that evolution is trying to achieve. And I think this notion may be the crux of the problems in this thread. You seem to want to liken evolution to breeding. While there are some similarities, ultimately the analogy misleads you. Evolution isn't trying to make new species. Evolution is simply a process. Think of the Mississippi River. It flows downhill. At the end, it deposits massive amounts of silt and has gradually built up a delta of deposited material. But you'd never say that the purpose of the river was to deposit that stuff down there. It just happened as a natural result of the river.
I think that you somehow have the notion that evolution is trying to make new species, and in order to maintain the integrity of that new species, it has to eliminate the genetic inputs that aren't part of that species, just like a dog breeder. But evolution isn't trying to make new species. New species sometimes happen. But that is simply an artifact of the effort to survive. In the end, that's all that evolution is about, trying to survive.

Ridicule is the only weapon which can be used against unintelligible propositions. Ideas must be distinct before reason can act upon them; and no man ever had a distinct idea of the trinity. It is the mere Abracadabra of the mountebanks calling themselves the priests of Jesus. -- Thomas Jefferson
For we know that our patchwork heritage is a strength, not a weakness. We are a nation of Christians and Muslims, Jews and Hindus -- and non-believers. -- Barack Obama
We see monsters where science shows us windmills. -- Phat

This message is a reply to:
 Message 124 by Faith, posted 03-28-2010 2:54 PM Faith has not replied

  
subbie
Member (Idle past 1513 days)
Posts: 3509
Joined: 02-26-2006


Message 135 of 851 (552450)
03-29-2010 8:53 AM
Reply to: Message 129 by Faith
03-29-2010 1:22 AM


Re: ANOTHER MID-THREAD RECON
Faith, I previously responded only to question 7 as I felt that was the only question for which I had a helpful response. You then asked that we respond to all the questions, so I'll give it my best shot. In addition, I'll modify my previous answer to 7 in light of your comments.
1) In domestic breeding -- let's stick to dogs -- do you agree that you get and maintain a breed by being sure you breed it with its own type?
Well, that's certainly not how you get a breed. As far as how you maintained a breed, haven't the foggiest idea. I'm not a dog breeder and I've never looked into it. I am curious about the genesis of your understanding. How many dog breeders have you talked to?
2) Do you agree that this is to protect the breed's particular allele complement from contamination from alleles of other dog types?
Well, since I don't agree that that's what dog breeders do, I'm not particularly inclined to speculate on reasons, but I doubt they use the word "contaminate."
3) Do you agree that any dog breed possesses a very limited genetic diversity with respect to the total dog population?
Yes.
4) Do you agree that it is its limited genetic diversity that is the basis for the characteristics of the breed itself and that if there is any increase in the genetic diversity the breed will lose its character at least to some extent?
Well, that's two questions asking two very different things. As far as the first part, I don't know. As far as the second part, absolutely not. Genetic diversity is increasing in every breed every day a litter is born. The genetic material from the sire and the bitch recombine in unique ways to create pups. I know you don't want that fact to be the focus in a thread dedicated to the reduction of genetic diversity, but it's a fact nonetheless.
5) Do you agree that Darwin based his natural selection on domestic selection?
Nope.
6) Do you agree that natural selection is the "engine of evolution?"
I don't know what you mean by "engine of evolution," so I can't answer that question.
If I were to imagine what you might mean, I would suppose that an engine is something that provides impetus to something else, that powers it forward. I might then compare that to the steering wheel, which gives direction to the impetus. If I were to look at it in that way, I would disagree that natural selection is the "engine of evolution." I would instead say that mutations are the engine of evolution and natural selection is the steering wheel.
If you are thinking of the engine of evolution in a different way, please explain. My answer might change.
7) Do you agree that the end goal of evolution is speciation or is evolution simply any change at all whether it ever leads to speciation or not?
Evolution is descent with modification. It may result in speciation, it may not. If you want to talk metaphorically about the end goal of evolution, it is simply survival. It really is very elegant in its simplicity.
Each generation, there are more organisms born than can survive to maturity to reproduce. Thus, they are competing with one another for resources. They are also competing with some other organisms for some of the resources. Some of them will be better at competing than others. These better competitors will pass more of their genetic material onto the next generation. Then the whole process starts over again.
That's really all there is to it. The rest is just details. The end goal of evolution is survival. It's really that simple.
Most importantly, evolution has no end goal. There is no result that evolution is trying to achieve. And I think this notion may be the crux of the problems in this thread. You seem to want to liken evolution to breeding. While there are some similarities, ultimately the analogy misleads you. Evolution isn't trying to make new species. Evolution is simply a process. Think of the Mississippi River. It flows downhill. At the end, it deposits massive amounts of silt and has gradually built up a delta of deposited material. But you'd never say that the purpose of the river was to deposit that stuff down there. It just happened as a natural result of the river.
I think that you somehow have the notion that evolution is trying to make new species, and in order to maintain the integrity of that new species, it has to eliminate the genetic inputs that aren't part of that species, just like a dog breeder. But evolution isn't trying to make new species. New species sometimes happen. But that is simply an artifact of the effort to survive. In the end, that's all that evolution is about, trying to survive.

Ridicule is the only weapon which can be used against unintelligible propositions. Ideas must be distinct before reason can act upon them; and no man ever had a distinct idea of the trinity. It is the mere Abracadabra of the mountebanks calling themselves the priests of Jesus. -- Thomas Jefferson
For we know that our patchwork heritage is a strength, not a weakness. We are a nation of Christians and Muslims, Jews and Hindus -- and non-believers. -- Barack Obama
We see monsters where science shows us windmills. -- Phat

This message is a reply to:
 Message 129 by Faith, posted 03-29-2010 1:22 AM Faith has not replied

  
subbie
Member (Idle past 1513 days)
Posts: 3509
Joined: 02-26-2006


Message 207 of 851 (554150)
04-06-2010 4:16 PM
Reply to: Message 206 by Faith
04-06-2010 4:05 PM


Re: In Faith's defense...
In other words, you'd be convinced of the truth of the ToE if we show you something that is the exact opposite of what the ToE predicts.
Curiouser and curiouser.

Ridicule is the only weapon which can be used against unintelligible propositions. Ideas must be distinct before reason can act upon them; and no man ever had a distinct idea of the trinity. It is the mere Abracadabra of the mountebanks calling themselves the priests of Jesus. -- Thomas Jefferson
For we know that our patchwork heritage is a strength, not a weakness. We are a nation of Christians and Muslims, Jews and Hindus -- and non-believers. -- Barack Obama
We see monsters where science shows us windmills. -- Phat

This message is a reply to:
 Message 206 by Faith, posted 04-06-2010 4:05 PM Faith has replied

Replies to this message:
 Message 211 by Faith, posted 04-06-2010 11:02 PM subbie has replied

  
subbie
Member (Idle past 1513 days)
Posts: 3509
Joined: 02-26-2006


Message 214 of 851 (554227)
04-07-2010 12:19 AM
Reply to: Message 211 by Faith
04-06-2010 11:02 PM


Re: In Faith's defense...
Kinda the same way Dawkins would be convinced of the falseness of evolution if a rabbit were found in the precambrian, which is the opposite of what creationism would predict too.
Not sure that Darwin ever considered that question, actually, but I understand your point.
As usual, however, you miss the point. You talk in terms of disproving creationism, when that hasn't been an issue for 150 years. So whether creationism would predict it or not is a moot point. Moreover, there have been several creationists who would have claimed a rabbit in the precambrian would have been a prediction of and conclusive proof of creationism. In fact, you'd be hard pressed to describe any hypothetical evidence that a creationist couldn't reconcile with the actions of an omnipotent creator. It's that ability to assimilate all possible evidence that makes creationism worthless as a scientific theory. Any theory that explains everything explains nothing.

Ridicule is the only weapon which can be used against unintelligible propositions. Ideas must be distinct before reason can act upon them; and no man ever had a distinct idea of the trinity. It is the mere Abracadabra of the mountebanks calling themselves the priests of Jesus. -- Thomas Jefferson
For we know that our patchwork heritage is a strength, not a weakness. We are a nation of Christians and Muslims, Jews and Hindus -- and non-believers. -- Barack Obama
We see monsters where science shows us windmills. -- Phat

This message is a reply to:
 Message 211 by Faith, posted 04-06-2010 11:02 PM Faith has replied

Replies to this message:
 Message 216 by Faith, posted 04-07-2010 1:28 AM subbie has not replied

  
Newer Topic | Older Topic
Jump to:


Copyright 2001-2023 by EvC Forum, All Rights Reserved

™ Version 4.2
Innovative software from Qwixotic © 2024