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Author Topic:   Convergent Evolution - Reasonable conclusion? or convenient excuse?
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:
 Message 63 by Taq, posted 06-16-2010 1:58 PM BobTHJ has not replied
 Message 65 by Percy, posted 06-16-2010 8:25 PM BobTHJ has not replied
 Message 97 by ramoss, posted 06-24-2010 11:58 AM BobTHJ has not replied

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


Message 61 of 107 (565379)
06-16-2010 1:02 PM
Reply to: Message 51 by Percy
06-15-2010 11:46 AM


quote:
Can you provide an example or two of organisms in this last 5%?
I already provided one. Bats and dolphins.
quote:
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?
A good ontological model. Yes, I have answered this before.

This message is a reply to:
 Message 51 by Percy, posted 06-15-2010 11:46 AM Percy has replied

Replies to this message:
 Message 62 by New Cat's Eye, posted 06-16-2010 1:17 PM BobTHJ has not replied
 Message 66 by Percy, posted 06-16-2010 8:55 PM BobTHJ has not replied

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


Message 70 of 107 (565866)
06-21-2010 4:39 PM


Rather than reply post-by-post I'll consolidate all replies to all outstanding posts here in hopes of reducing duplication/workload. Apologies - for I know this breaks the automation of the handy threaded replies within a thread system.
Taq asks (Message 56, and Percy follows up with a similar question in Message 65) why vastly different designs do not constitute 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?
As a counter-example, consider the work of any famous artist. While individual works may vary considerably both in scope and theme there is an underlying 'signature' to their work, and any discriminating art-lover can quickly discern the artist from the work. Common design does not expect uniformity, it expects some similarity - the designer's 'signature'.
To clarify my comments on the phylogenetic tree (referenced by Taq in Message 58, Catholic Scientist in Message 62, and Percy in Message 66, and RAZD in Message 67): The ontology is a useful tool to group organisms on similarities. Those similarities may occur at the genetic level, the morphological level, the behavioral level, etc. Since the inception of phylogentics similarities determine how organisms are grouped. As we've discussed in this thread - grouping organisms on a single similarity is ineffective, instead they are (typically) grouped with other organisms sharing the most similarities. My point is that this leads to cases (such as bat/dolphin echolocation) where organisms that share one or more similarities at some level are not closely grouped. My statement is not made to validate or invalidate common ancestry (the conclusion many draw) - I am simply referring to the ontological model.
Taq in Message 63 (and expanded by RAZD in Message 64):
"Of course - if organisms lacked significant similarity to each other then you would have evidence against common design."--BobTHJ
This is exactly the case for cephalopod eyes and vertebrate eyes. They serve the same function in the same environment, and yet they are significantly dissimilar.
Dissimilarity in a single feature is not significant. Note that cephalopods and vertebrates still share the same cellular structure, the same DNA structure, etc. There is a host of similarities - it reeks of common design.
Percy in Message 66:
Sorry if I missed it, but if you could just provide a link to the message with this answer I'll go take a look. Otherwise, could you please answer the question? A nested hierarchy can, by definition, have but a single root node. The phenotypic evidence strongly indicates a nested hierarchy, as was obvious even before Darwin, and the genetic evidence proves it conclusively.
There are a lot of assumptions made to force the ontology to fit the nested-heirarchy "root node" model needed for common ancestry. Here's where the system seems to break down. While a "best guess" path has been established it requires a lot of faith in processes supposed to occur millions or billions of years in the past for which there is scant evidence. I'm happy to discuss aspects of this further if you deem it to be adequately on-topic.
RAZD in Message 67:
What I take issue with on these claims are:
that they do not differentiate any observations from what is expected from evolution,
that the scenarios you suggest would invalidate your design hypothesis would also invalidate evolution, and
that this just appears to be your way of explaining the results of evolution to yourself, without risking any prediction that would falsify your design hypothesis
I understand that darwinian evolution would have the same expectations. My point was not to find specific evidence that would invalidate one while validating the other. Both models (from a wide-perspective) fit the evidence well - I doubt we'd be discussing this did they not. If anything, the burden of proof lies with you here - darwinain evolution (being the newer theory attempting to supplant the old) should need to demonstrate why it is correct and creation is not. What evidence is there that validates the pair of abiogenesis/darwinian evolution but invalidates common design of a set of created kinds?
Dr Adequate in Message 68:
The first is: if you know that, then why advance a hypothesis which you know to be contradicted by the facts?
The second is the question you ducked the first time I raised it: why should there be a naturalistic explanation that predicts the facts so perfectly?
I'm not following your first question. Every hypothesis I have advocated seems to fit the evidence - if it did not I wouldn't advocate for it.
As to your second question - I don't think the naturalistic explanation predicts the facts perfectly. The naturalistic explanation has been in a constant state of adjustment specifically because it has failed to predict many facts. As I've mentioned before - to some extent this is good science, but when the special pleading begins to outweigh the evidence it may be time to abandon the theory.
I'll answer articulett's Message 69 separately, because (s)he asks a number of distinct questions more appropriately answered by a point-by-point reply.

Replies to this message:
 Message 73 by Taq, posted 06-21-2010 5:28 PM BobTHJ has not replied
 Message 74 by Dr Adequate, posted 06-21-2010 5:29 PM BobTHJ has not replied
 Message 78 by RAZD, posted 06-21-2010 7:06 PM BobTHJ has not replied
 Message 80 by Percy, posted 06-22-2010 8:49 AM BobTHJ has not replied

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


Message 71 of 107 (565868)
06-21-2010 4:57 PM
Reply to: Message 69 by articulett
06-17-2010 2:02 AM


quote:
Why wouldn't your god be more specific and obvious and "intelligent" in his design so that it didn't look exactly like what we'd expect from evolution without an overseer? Why so kludgey?
Kludgey? Care to give an example of kludgey? YEC does expect some degree of 'kludgeyness' as a result of decay in the genome since creation - but this type of kludgeyness should be as a result of degredation - not as a result of natural selection's imperfect means of assembling functions.
quote:
If you see convergent evolution as evidence of creation, how do you imagine things would look different if there was no "intelligent designer"?
As previously stated, if there were no common designer then we could expect to see little to no similarity between organisms. Each would have different "building blocks" - they wouldn't share common cellular structure, DNA, etc.
quote:
If you were wrong about there being a designer would you want to know? And, what, if any, evidence could convince you?
At this point I am doubtful that scientific evidence alone could convince me of the lack of a designer - I am convinced by the spiritual evidence. However, scientific evidence could convince me that the designer used darwinian evolution as a method for populating life on the planet. As to what form that evidence would take - I am uncertain - I honestly haven't given it much thought.
quote:
I don't want to deny an existence of a god anymore than I want to deny the idea that intelligent aliens from another planet seeded life on earth, but there just is no evidence for anyone to insert such notions into the equation. They don't further understanding and may send people off in the wrong direction confirming their biases
As I've mentioned before (but you may not have seen since it appears you are new - welcome!) I have more than sufficient evidence to insert the notion of a designer into the equation. I'll concede that atheists do not (shame too, cause they don't know what they're missing).
quote:
Why would someone want to deny the evidence of god if there was actual evidence for god? And does the expertise of theistic evolutionists like Francis Collins and Ken Miller have no credence in your brand of faith? Do you think they are being fooled while you have accesses some divine "higher truth"? (Are you a YEC?)
Yes, I subscribe to the YEC model. Yes I understand many Christians do not. This is really a religious question - and is off topic, so I'll keep my answer brief - and if you'd like to discuss further let's take it to another thread. The Bible (the 'handbook' for the Christian faith) does not preclude other models - though theologically they don't seem to hold up as well as YEC. Do I have access to "higher truth"? No...we all share access to the same truth. I have chosen to advocate YEC because it seems to be the most theologically and scientifically consistent.

This message is a reply to:
 Message 69 by articulett, posted 06-17-2010 2:02 AM articulett has replied

Replies to this message:
 Message 72 by Taq, posted 06-21-2010 5:20 PM BobTHJ has not replied
 Message 75 by Dr Adequate, posted 06-21-2010 5:57 PM BobTHJ has not replied
 Message 76 by bluescat48, posted 06-21-2010 5:59 PM BobTHJ has not replied
 Message 77 by articulett, posted 06-21-2010 5:59 PM BobTHJ has not replied

  
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