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Author Topic:   Convergent Evolution - Reasonable conclusion? or convenient excuse?
RAZD
Member (Idle past 1405 days)
Posts: 20714
From: the other end of the sidewalk
Joined: 03-14-2004


Message 46 of 107 (565124)
06-14-2010 9:35 PM
Reply to: Message 44 by BobTHJ
06-14-2010 6:24 PM


Hi again BobTHJ,
Cases of common morphology without common genetics does not make common design an unreasonable conclusion.
Silly Design Institute: Let's discuss BOTH sides of the Design Controversy... ... at issue is the purpose of design that we can infer from the evidence.
Enjoy.

we are limited in our ability to understand
by our ability to understand
Rebel American 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 44 by BobTHJ, posted 06-14-2010 6:24 PM BobTHJ has seen this message but not replied

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


Message 47 of 107 (565131)
06-14-2010 10:07 PM
Reply to: Message 38 by BobTHJ
06-14-2010 1:07 PM


Re: superficial similarity but differences in the details
Hi again BobTHJ,
I haven't looked, but it is probably safe to assume that the vast majority of these species are the result of recent variation (we may define 'recent' differently, but suffice it to say that they have very close relatives) so it seems your figure should be substantially less. I also doubt that the wikipedia article is comprehensive in nature as I've seen mentions of several hundred or more cases of convergency. As a result it is likely the percentage is substantially higher than .005%.
Except that (1a) all the convergent evolution examples include living species AND some fossil bits of evidence PLUS (1b) some of the examples are only specific traits (such as opposable thumbs) rather than the appearance of the whole organisms, as in the example of the flying squirrel and sugar glider, WHILE (2) "The number of species on the planet that have been documented by scientists has risen to 1.9 million" is only currently living species.
Therefore a proper comparison would be much lower than 0.005% (take out the fossil examples, take out the single feature examples).
As I stated in another thread - I suspect the phylogenetic tree to be a 95%+ accurate categorization of living organisms (ontology only - no common descent implied) - with these non-conforming cases composing the other <5%. Just stating this for the record so everyone knows where I stand.
Of course, and you also must realize that opinion is completely impotent at altering reality in any way. You are free to hold whatever opinion you wish, but if you are ignoring reality and evidence that contradicts your opinion, the only one you are fooling is yourself.
Yes - and that seems to be what happens. Organisms are placed into the phylogenetic tree at the location where they show the most similarity to the surrounding organisms. This reflects a good ontology model - though it does lead to some inconsistency since some organisms classed in different clades still share similarities not shared by other closely classed organisms.
Perhaps you would like to offer some evidence to show what you mean? Are you talking about lost traits?
Nobody is claiming that the nested hierarchies are necessarily true, just that they are the best known explanation of life as we know it, based on the information available.
Curiously, these nested hierarchies can be developed (a) in the traditional morphological detailed study method that has been used in biology since Linnaeus, and (b) based on genetic information.
With design there is no reason for these two trees to be the same.
With evolution the two trees must be the same, and they are.
Enjoy.

we are limited in our ability to understand
by our ability to understand
Rebel American 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 38 by BobTHJ, posted 06-14-2010 1:07 PM BobTHJ has replied

Replies to this message:
 Message 55 by BobTHJ, posted 06-16-2010 11:21 AM RAZD has replied

  
Dr Adequate
Member (Idle past 285 days)
Posts: 16113
Joined: 07-20-2006


Message 48 of 107 (565144)
06-15-2010 1:13 AM
Reply to: Message 44 by BobTHJ
06-14-2010 6:24 PM


Common design is evident in all aspects of our universe - from the atomic to the astronomic.
Though apparently less "evident" to atomic physicists and astronomers than it is to you.
Cases of common morphology without common genetics does not make common design an unreasonable conclusion.
Well, if we imagine a designer who is at once all-powerful and (from our perspective) infinitely capricious, then I guess he could have done anything. "Last Thursdayism", for example, becomes a theoretical possibility. We become unable in principle to rule out "common design" because we have absolutely no concept of what such a thing would look like.
However, while such a hypothetical supernatural being might have done anything, evolution can only do a circumscribed set of things: and we find that those are the only things that we actually observe.
Now, how are we to account for this?
(a) By a complete coincidence, God's whims always led him to create just those things that the theory of evolution would predict.
(b) God deliberately created the living world in such a way as to fool biologists into thinking that it was the product of evolution.
(c) Evolution happened.

This message is a reply to:
 Message 44 by BobTHJ, posted 06-14-2010 6:24 PM BobTHJ has replied

Replies to this message:
 Message 59 by BobTHJ, posted 06-16-2010 12:19 PM Dr Adequate has replied

  
Percy
Member
Posts: 22394
From: New Hampshire
Joined: 12-23-2000
Member Rating: 5.2


Message 49 of 107 (565173)
06-15-2010 10:03 AM
Reply to: Message 39 by BobTHJ
06-14-2010 5:15 PM


Re: What is the ID Explanation?
BobTHJ writes:
Does ID have something to account for or explain? Convergence is a (potential) problem for common-ancestry evolution, not ID. The common Designer readily explains any convergence under ID.
Taq also replied to your message and asked a good question. Are both convergence and non-convergence evidence for ID? If so, can you explain?
But my question was about how the common Designer explains convergence. If humans are the model for how the Designer designs, as is often suggested, then what leads you to expect convergence since humans will not design from scratch but will reuse an existing design, if one is available.
Let's imagine that a human wanted to design an engine, but needed it to be more powerful than existing engines. He would take an existing design and modify it. But what if he didn't have an existing design. Maybe he wanted a Wankel engine, but he worked for Ford instead of Mazda, so he couldn't start with an existing design. In that case he would design from scratch.
Now let's consider the equivalent case for your designer. Let's say he wants an eye with some new feature, maybe greater resolution. If he designs like a human then he would modify an existing design. He would never have to design from scratch if there were prior designs, because the designer is the only company.
But the designer has obviously designed from scratch at least several times with the eye, and this tells us that there must have been several designers who were unwilling to share designs with one another. One designer designed the octopus eye and put the light rods in front of the blood supply, but then he wouldn't share that design with the designer of mammals, so that designer designed from scratch and put the rods in back of the blood supply.
What I just explained is what I was asking you about when I asked what convergent evolution tells us about the designer.
--Percy

This message is a reply to:
 Message 39 by BobTHJ, posted 06-14-2010 5:15 PM BobTHJ has replied

Replies to this message:
 Message 60 by BobTHJ, posted 06-16-2010 12:46 PM Percy has replied

  
Taq
Member
Posts: 9974
Joined: 03-06-2009
Member Rating: 5.7


Message 50 of 107 (565181)
06-15-2010 10:57 AM
Reply to: Message 44 by BobTHJ
06-14-2010 6:24 PM


Common design is evident in all aspects of our universe - from the atomic to the astronomic.
Statements like this are usually followed by the evidence that you claim exists.
Cases of common morphology without common genetics does not make common design an unreasonable conclusion.
Your argument is that a common designer will reuse designs. So how can we conclude a common designer when an obvious chance to reuse design is not taken? Your conclusion is unreasonable because any evidence whatsoever conforms to your model. If a conclusion can explain anything it explains nothing.

This message is a reply to:
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Percy
Member
Posts: 22394
From: New Hampshire
Joined: 12-23-2000
Member Rating: 5.2


Message 51 of 107 (565185)
06-15-2010 11:46 AM
Reply to: Message 42 by BobTHJ
06-14-2010 6:10 PM


BobTHJ writes:
95%+ of organisms fit nicely into a nested hierarchy. However, the hierarchy can not fully model that last <5% because there will be shared features/genes with other not closely grouped organisms.
Can you provide an example or two of organisms in this last 5%?
And, though I've posted it elsewhere I'll restate it here for completeness: nested hierarchy does not imply common ancestry...
And though I've posted it elsewhere I'll restate it here because you haven't answered it yet: what else could a nested hierarchy possibly imply? How many trunks can a tree have?
--Percy

This message is a reply to:
 Message 42 by BobTHJ, posted 06-14-2010 6:10 PM BobTHJ has replied

Replies to this message:
 Message 61 by BobTHJ, posted 06-16-2010 1:02 PM Percy has replied

  
BobTHJ
Member (Idle past 4998 days)
Posts: 119
Joined: 06-02-2010


Message 52 of 107 (565356)
06-16-2010 10:45 AM
Reply to: Message 41 by Taq
06-14-2010 5:28 PM


Re: What is the ID Explanation?
quote:
So if we found examples of non-convergence this would be evidence against a common designer?
If we failed to find significant similarity between life forms it would evidence against a common designer.

This message is a reply to:
 Message 41 by Taq, posted 06-14-2010 5:28 PM Taq has replied

Replies to this message:
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BobTHJ
Member (Idle past 4998 days)
Posts: 119
Joined: 06-02-2010


Message 53 of 107 (565360)
06-16-2010 10:50 AM
Reply to: Message 45 by Wounded King
06-14-2010 6:34 PM


quote:
Can you think of anything that would? And does it make a more reasonable conclusion than the one we already have which is supported by the material processes we can observe and understand?
Of course - if organisms lacked significant similarity to each other then you would have evidence against common design. For example, if organisms didn't share a similar cell structure but instead most used a basic anatomical unit that was different from other organisms this would be evidence against common design. Or if organisms didn't all use DNA/RNA but instead each used its own method of storing data - that would be evidence against common design.
Both are fairly reasonable conclusions - they both fit the data.

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Dr Jack
Member
Posts: 3514
From: Immigrant in the land of Deutsch
Joined: 07-14-2003
Member Rating: 8.7


Message 54 of 107 (565363)
06-16-2010 11:12 AM
Reply to: Message 53 by BobTHJ
06-16-2010 10:50 AM


Of course - if organisms lacked significant similarity to each other then you would have evidence against common design. For example, if organisms didn't share a similar cell structure but instead most used a basic anatomical unit that was different from other organisms this would be evidence against common design. Or if organisms didn't all use DNA/RNA but instead each used its own method of storing data - that would be evidence against common design.
How is that evidence against common design? Do designers always use the same elements?

This message is a reply to:
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BobTHJ
Member (Idle past 4998 days)
Posts: 119
Joined: 06-02-2010


Message 55 of 107 (565366)
06-16-2010 11:21 AM
Reply to: Message 47 by RAZD
06-14-2010 10:07 PM


Re: superficial similarity but differences in the details
quote:
Of course, and you also must realize that opinion is completely impotent at altering reality in any way. You are free to hold whatever opinion you wish, but if you are ignoring reality and evidence that contradicts your opinion, the only one you are fooling is yourself.
Of course. You disagree with my opinion that the phylogenetic tree correctly models similarity (both morphological and genetic) to a degree higher than 95%? I didn't think many people would fight me on that assumption.
quote:
Perhaps you would like to offer some evidence to show what you mean? Are you talking about lost traits?
Sure, echolocating in bats and dolphins. They are not classed together in the phylogenetic tree (nor should they be if you want the most accurate ontological model possible) yet share a similarity not shared by other closely grouped organisms.
quote:
With design there is no reason for these two trees to be the same.
With evolution the two trees must be the same, and they are.
A high degree of correlation between genomes and morpholocial features fits well with a design hypothesis. Just because darwinian evolution fails without that correlation doesn't mean it is the more reasonable conclusion.

This message is a reply to:
 Message 47 by RAZD, posted 06-14-2010 10:07 PM RAZD has replied

Replies to this message:
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Taq
Member
Posts: 9974
Joined: 03-06-2009
Member Rating: 5.7


Message 56 of 107 (565368)
06-16-2010 11:28 AM
Reply to: Message 52 by BobTHJ
06-16-2010 10:45 AM


Re: What is the ID Explanation?
If we failed to find significant similarity between life forms it would evidence against a common designer.
There are significant dissimilarity between the light bulb and the phonograph. Does this mean that they were not created by the same person, Thomas Edison?
Also, there is significant dissimilarity between the cephalopod eye and the vertebrate eye. Does this mean that they were not created by a common designer? There is also significant dissimilarity between the bat wing and the bird wing. Is this evidence against a common designer as well?

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Taq
Member
Posts: 9974
Joined: 03-06-2009
Member Rating: 5.7


Message 57 of 107 (565369)
06-16-2010 11:30 AM
Reply to: Message 55 by BobTHJ
06-16-2010 11:21 AM


Re: superficial similarity but differences in the details
A high degree of correlation between genomes and morpholocial features fits well with a design hypothesis.
So the tasmanian wolf and the grey wolf should have genomes closer to each other than a grey wolf and a lion? Is that your prediction?

This message is a reply to:
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Taq
Member
Posts: 9974
Joined: 03-06-2009
Member Rating: 5.7


Message 58 of 107 (565373)
06-16-2010 12:07 PM
Reply to: Message 55 by BobTHJ
06-16-2010 11:21 AM


Re: superficial similarity but differences in the details
Sure, echolocating in bats and dolphins. They are not classed together in the phylogenetic tree (nor should they be if you want the most accurate ontological model possible) yet share a similarity not shared by other closely grouped organisms.
Echolocation is a behavior. The morphological structures used by dolphins and bats is quite different. For example, in the dolphin there is a structure called the melon. It is a fatty bulge in front of the skull that is used to focus sound waves which then allows for echolocation. No homologous structure is found in bats. The actual morphological adaptations for echolocation in bats and dolphins is different, therefore falsifying common design (right?). The only thing they do share is 10-14 amino acid substitutions in the prestin gene which is involved in sound sensitivity in all mammals.
Edited by Taq, : No reason given.

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BobTHJ
Member (Idle past 4998 days)
Posts: 119
Joined: 06-02-2010


Message 59 of 107 (565375)
06-16-2010 12:19 PM
Reply to: Message 48 by Dr Adequate
06-15-2010 1:13 AM


quote:
However, while such a hypothetical supernatural being might have done anything, evolution can only do a circumscribed set of things: and we find that those are the only things that we actually observe.
Now, how are we to account for this?
(a) By a complete coincidence, God's whims always led him to create just those things that the theory of evolution would predict.
(b) God deliberately created the living world in such a way as to fool biologists into thinking that it was the product of evolution.
(c) Evolution happened.
Hmm...you see this as evidence for evolution. I see this as those who wish to deny the existence or involvement of God* devising the most reasonable naturalistic explanation to explain His creation. Not at all unlikely.
*And because I know it's coming - no I'm not implying all evolutionists are atheists.

This message is a reply to:
 Message 48 by Dr Adequate, posted 06-15-2010 1:13 AM Dr Adequate has replied

Replies to this message:
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BobTHJ
Member (Idle past 4998 days)
Posts: 119
Joined: 06-02-2010


Message 60 of 107 (565377)
06-16-2010 12:46 PM
Reply to: Message 49 by Percy
06-15-2010 10:03 AM


Re: What is the ID Explanation?
quote:
Taq also replied to your message and asked a good question. Are both convergence and non-convergence evidence for ID? If so, can you explain?
I don't think convergence (or lack thereof) constitutes evidence for or against ID. It would constitute evidence against darwinism if found in significant quantity.
quote:
But my question was about how the common Designer explains convergence. If humans are the model for how the Designer designs, as is often suggested, then what leads you to expect convergence since humans will not design from scratch but will reuse an existing design, if one is available.
Let's imagine that a human wanted to design an engine, but needed it to be more powerful than existing engines. He would take an existing design and modify it. But what if he didn't have an existing design. Maybe he wanted a Wankel engine, but he worked for Ford instead of Mazda, so he couldn't start with an existing design. In that case he would design from scratch.
Now let's consider the equivalent case for your designer. Let's say he wants an eye with some new feature, maybe greater resolution. If he designs like a human then he would modify an existing design. He would never have to design from scratch if there were prior designs, because the designer is the only company.
But the designer has obviously designed from scratch at least several times with the eye, and this tells us that there must have been several designers who were unwilling to share designs with one another. One designer designed the octopus eye and put the light rods in front of the blood supply, but then he wouldn't share that design with the designer of mammals, so that designer designed from scratch and put the rods in back of the blood supply.
What I just explained is what I was asking you about when I asked what convergent evolution tells us about the designer.
You forgetting that design is purposeful. Yes there are several variations on the eye. This is because each differently designed eye serves a specific function to its host organism. Besides, common design doesn't mean the Designer MUST reuse material.

This message is a reply to:
 Message 49 by Percy, posted 06-15-2010 10:03 AM Percy has replied

Replies to this message:
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