Does evolution have a chance?

[theFijian]

Who's Black Jack?

Micaiah now resorts to baiting.

 

[Jet Black]

or a genuine mistake. I don't care which as neither are my name (obviously )

 

[Dragar]

The evolution of the bird wing and the wing of a bat is said to be convergent. It is supposed to have evolved independently. It is true that evolutionary theory requires there to be an outcome in which case the probability is 1. However, considering all the possible paths that evolution could take, the chance of it taking the same path twice is extremely remote. It is easy to estimate the probabality based on these numbers.

Let's grant that premise for argument's sake: it's extremely remote for any particular feature to be produced by two seperate evolutionary pathways.

Now, what is the probability that at least one feature (not specifying which ones) will be produced by two seperate evolutionary pathways?

I'd say the odds are pretty good, considering how many features there are.

Because remember - we didn't just have wings that might have been convergent. It could have been shells, or skeletons, or kidneys or limbs or eyes or hair or...

There are lots of things it could have been, but weren't. They're the chances that didn't pan out. You're just focusing on the one that did. And considering how many chances we had, it was pretty likely it would happen once.

If you have enough chances for an incredibly unlikely event to take place, you're almost certain to get that event.

 

[Micaiah]

sorry, but what I am saying is a bit more than "just what I think happened from an evolutionists perspective" The issue at hand is that Spetner is implicitly claiming that this gene must have evolved multiple times if evolution is correct, and since the probability of the same gene evolving multiple times is incredibly small, then this would be evidence against evolution.

This is a really strange claim, since the gene exists in more basal organisms, and does far more than just this one thing. The only evidence I could see him having to support his position is if Pax6 did not exist in more basal organisms and did not do more (particularly more fundamental) things than be a member of the cascade leading to eye development. but it does exist in more basal organisms, and it is involved in far more fundamental things than just eye development. so where is his argument?

Thanks for the links people. I am unfortunately unable to read the full text of the article which makes it difficult. I suspect it is not going to say much different to what has been said thus far.

Take a step back from this particular issue for a minute. The main thrust of the argument is that the eye was supposed to have evolved substantially independently in three distinct phyla. I understand that is agreed with by evolutionists. The chance of this occurring has been shown to be extremely remote. I accept that a quantitative assessment of the number of genes and nucleotides that were supposed to have evolved would make the argument more clear. An attempt was made to do that with one of the genes, but it seems that can be explained from the evolutionists perspective as resulting from a common basal gene.

It does raise the whole question of how these parts of an organism was supposed to develop independently. It will be interesting to investigate convergence further.

 

[Micaiah]

Micaiah now resorts to baiting.

No, just trying to liven things up a little and see how many people out there were still awake.

 

[Micaiah]

Let's grant that premise for argument's sake: it's extremely remote for any particular feature to be produced by two seperate evolutionary pathways.

Now, what is the probability that at least one feature (not specifying which ones) will be produced by two seperate evolutionary pathways?

I'd say the odds are pretty good, considering how many features there are.

Because remember - we didn't just have wings that might have been convergent. It could have been shells, or skeletons, or kidneys or limbs or eyes or hair or...

There are lots of things it could have been, but weren't. They're the chances that didn't pan out. You're just focusing on the one that did. And considering how many chances we had, it was pretty likely it would happen once.

If you have enough chances for an incredibly unlikely event to take place, you're almost certain to get that event.

Granted we have only considered the development of one part be it a wing, eye, or brain. I understand evolutionists would claim that a large number of these things were being developed simulatanously which is what you're saying. I don't think that makes evolution easier. For the statistical analysis, you could lump genes for the the nervous system and blood supply to the eye in with the eye. It just means you have got a lot more steps to take for something to be fully functional. Instead of 500, it could become many thousand. That increases the number of paths that the evolution can take, and reduces the probability of convergence.

The mind boggles to think how anyone could claim that all these things could develop in unison through random chance and natural selection.

 

[Karl - Liberal Backslider]

Micaiah - the eye evolved independently - and differently - in different phyla. However, the basal gene to which you are referring predates the eye and was present in the common ancestors of all sighted - and many unsighted - groups. The basal gene only evolved the once and was inherited by several lineages, some of which evolved eyes using that basal gene.

Is that clear enough?

 

[Jet Black]

Take a step back from this particular issue for a minute. The main thrust of the argument is that the eye was supposed to have evolved substantially independently in three distinct phyla. I understand that is agreed with by evolutionists. The chance of this occurring has been shown to be extremely remote.

only by Spetner, and he was quoting a Pax6 study, and turned out to be wrong about what he was claiming about it. So I still don't see where your basis for claiming that multiple evolution of the eye is really remote from.

I accept that a quantitative assessment of the number of genes and nucleotides that were supposed to have evolved would make the argument more clear. An attempt was made to do that with one of the genes, but it seems that can be explained from the evolutionists perspective as resulting from a common basal gene.

As I said, the problem is not so much that - though it certainly does appear that this particular gene is more basal, but that Spetner is implicitly claiming that the gene evolved twice or more, with absolutely nothing to base that claim on. it's not just that evolutionists claim that the gene came from a more basal gene, it is that there is evidence for it. The gene in question does other more fundamental things in the organisms as well as being involved in the cascade of eye formation and exists in a number of organisms that don't even have eyes. Spetner's claim only works now if Pax6 had to evolve both in all these organisms with eyes, and all these organisms without eyes, and evolved in all groups in such a way that it did the same in all of them. So now spetner is in the unenviable position whereby his idea is currently centred on a gene that doesn't have the properties that he needs to support his point. he is merely claiming that there are examples of "highly unlikely convergence" without actually being able to point to one.

 

[Jet Black]

It just means you have got a lot more steps to take for something to be fully functional.

what do you mean "before it is fully functional" are you suggesting at some point the structures are only partially functional? partially functional with respect to what exactly?

 

[Dragar]

Granted we have only considered the development of one part be it a wing, eye, or brain. I understand evolutionists would claim that a large number of these things were being developed simulatanously which is what you're saying.

I'm not saying that at all!

I'm saying that you're taking one specific event and saying how improbable it is, when actually we had lots of chances at various features being convergent. It's not a suprise at least one feature is convergent when we have so many that could be (but aren't).

The specific event (convergence of wings) might be improbable, but the odds of something being convergent are pretty high. And if something else were convergent, we'd be sat here discussing that instead.

 

[Micaiah]

Jet Black,

As stated above, I think you have pointed out a weakness in an example used to illustrate a point in the argument. I don't think that means we need to dicard the entire argument.

 

[Micaiah]

The specific event (convergence of wings) might be improbable, but the odds of something being convergent are pretty high. And if something else were convergent, we'd be sat here discussing that instead.

Have another look at the start of the thread at the estimate of the probability of a single step. I think that answers your question.

 

[Micaiah]

Micaiah - the eye evolved independently - and differently - in different phyla. However, the basal gene to which you are referring predates the eye and was present in the common ancestors of all sighted - and many unsighted - groups. The basal gene only evolved the once and was inherited by several lineages, some of which evolved eyes using that basal gene.

Is that clear enough?

Agreed. Thanks. What we need to know is how many of the nucleotides were added/changed in the hypothsised independent evolution of the eye in the different cases. Evolutionists obviously do not accept the gene mentioned above as part of that indpendent evolution.

 

[Jet Black]

Jet Black,

As stated above, I think you have pointed out a weakness in an example used to illustrate a point in the argument. I don't think that means we need to dicard the entire argument.

it is a bit of a redundant argument if there is no evidence for it.

 

[Jet Black]

Agreed. Thanks. What we need to know is how many of the nucleotides were added/changed in the hypothsised independent evolution of the eye in the different cases.

but what will that get us?

Evolutionists obviously do not accept the gene mentioned above as part of that indpendent evolution.

do you still think there is any basis on which to think they do not fit into the evolutionary model (after all, this is the whole point of spetner's claims, not to make any positive point, but just claim that something is impossible for evolution)

this is looking increasingly like nothing more than a variant of the ID argument.

 

[Nathan Poe]

Granted we have only considered the development of one part be it a wing, eye, or brain. I understand evolutionists would claim that a large number of these things were being developed simulatanously which is what you're saying.

They would claim it because that is exactly what we see in nature. simplified versions of eyes and wings appear all over the animal kingdom even today. Even "half a wing" serves a purpose, even if it does fly, so as long as the environment puts no pressure on the organism to evolve anything better, it won't.

I don't think that makes evolution easier. For the statistical analysis, you could lump genes for the the nervous system and blood supply to the eye in with the eye. It just means you have got a lot more steps to take for something to be fully functional.

Simple steps. What of it?

Instead of 500, it could become many thousand.

So?

That increases the number of paths that the evolution can take, and reduces the probability of convergence.

But still makes it possible.

The mind boggles to think how anyone could claim that all these things could develop in unison through random chance and natural selection.

If the mind is easily boggled. Others might look at it with a sense of wonder.

 

[Loudmouth]

I don't know if I referenced this study in this thread, but here it is. It shows that a Pax6 homolog in jellyfish (cnidiria) controls the production of well developed lensed eye. Cnidiria are just one step up from sponges in the "tree of life" and predate bilateria. There is also a link to the free full text article.

Int J Dev Biol. 2004;48(8-9):719-29.Related Articles, Links

[size=+1]Cubozoan jellyfish: an Evo/Devo model for eyes and other sensory systems.[/size]

Piatigorsky J, Kozmik Z.

National Eye Institute, National Institutes of Health, Bethesda, Maryland 20892-0704, USA. joramp@nei.nih.gov

Cnidaria are the most basal phylum containing a well-developed visual system located on specialized sensory structures (rhopalia) with eyes and statocyts. We have been exploring the cubozoan jellyfish, Tripedalia cystophora. In addition to containing simple photoreceptive ocelli, each rhopalium in Tridedalia has a large and small complex, camera-type eye with a cellular lens containing three distinct families of crystallins which apparently serve non-lenticular functions. Thus, Tridpedalia recruited crystallins by a gene sharing strategy as have mollusks and vertebrates. Tripedalia has a single Pax gene, PaxB, which encodes a structural and functional Pax 2/5/8-like paired domain as well as an octapeptide and Pax6-like homeodomain. PaxB binds to and activates Tripedalia crystallin promoters (especially J3-crystallin) and the Drosophila rhodopsin rh6 gene in transfection tests and induces ectopic eyes in Drosophila. In situ hybridization showed that PaxB and crystallin genes are expressed in the lens, retina and statocysts. We suggest from these results that an ancestral PaxB gene was a primordial gene in eye evolution and that eyes and ears (mechanoreceptors) may have had a common evolutionary origin. Thus, the numerous structural and molecular features of Tridpalia rhopalia indicate that ancient cubozoan jellyfish are fascinating models for evo/devo insights into eyes and other sensory systems.

 

[notto]

Is it just me or to most creationists arguments simply boil down to one of an Argument from Personal Incredulity. They start out with claims of probability but when they are examined, the strawmen removed, the actual evidence we have is applied, and the assumptions, poor analogies, and mathematics are corrected, they still cling to it because it 'boggles' their mind.

 

[Dragar]

Have another look at the start of the thread at the estimate of the probability of a single step. I think that answers your question.

Not really. You need to estimate the probability for any step to happen to rule out evolution. Aron-Ra said as much. And unfortunately, the chance are pretty darned close to 1.

 

[Aron-Ra]

Whats the starting point?

Please be specific so we can be sure you simply are not presenting a creationists strawman. Make sure your starting point is within the 'requirments of evolution' which you may or may not be able to define.

Starting point would be say an animal with forelimbs but without wings. Oh lets say it also has to evolve fingers as well, so I'll add another 753 nucleotides to the estimate, to give a total of 10, 753 nucleaotide substitutions and insertions.

Don't forget deletions. Why do creationists always omit deletions, unless they're arguing for "DEV-olution", in which case, they still don't admit additions?

But your starting point could be anything from already-feathered maniraptors like Sinornithosaurus mileni

all the way back to a Stegocephalian fish like Elginerpeton.

Please understand that forelimbs began as swimming paddles, then became legs, the grabbing arms, and then wings. So could you refine your starting point to one actual point please? Because what I see here is that all we would need is for the feathers to grow longer on the arms. What exactly is your problem with this?

Bat's wings, on the other hand, began completely differently, among Euarchontoglires with something like this flying lemur.

All you need here are longer fingers. An actual bat's wings are built on their fingers. The earliest birds still had fingers, but they weren't part of the wings, and were useless as part of the wing, so they were eventually lost. Do you see now how they're not really similar in any way other than their general function?