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Author Topic:   Vestigial Organs?
Dr Jack
Member (Idle past 397 days)
Posts: 3507
From: Leicester, England
Joined: 07-14-2003


Message 16 of 109 (554514)
04-08-2010 5:35 PM
Reply to: Message 7 by rockondon
04-08-2010 12:52 PM


I wouldn't use the appendix as an example of a vestigial organs. Studies into the distribution of the appendix and appendix-like organs in animals suggest that it is adaptive.

One possible function for the appendix is that it is there to reseed the gut with bacteria following a bout of diarrhea. This would also explain why removing the appendix is not harmful - the only societies which can safely remove an appendix are also societies in which diarrhea does not carry a significant risk of death.

My favourite example of vestigiality is stotting in Svalbard Reindeer.


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Faith
Member
Posts: 33400
From: Nevada, USA
Joined: 10-06-2001
Member Rating: 1.2


Message 17 of 109 (554520)
04-08-2010 5:53 PM
Reply to: Message 13 by Phage0070
04-08-2010 4:18 PM


I claim nothing about the relative merits of the explanation, merely wanted to correct the OP which assumed that creationists always see such things as vestigial organs as necessarily having a function.

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bluescat48
Member (Idle past 2481 days)
Posts: 2347
From: United States
Joined: 10-06-2007


Message 18 of 109 (554547)
04-08-2010 9:23 PM
Reply to: Message 6 by Faith
04-08-2010 12:06 PM


do have functions just not the original
I'm a creationist and I disagree with the creationists who think vestigial organs have a purpose. I think they once had a purpose but lost it. I wish we creationists could all get on the same page but right now it isn't happening.

Unfortunately for you, those creationists are right, most vestigal organs do have a function, just not the function the organ had in other species. Some vestiges have no function that can be derived, ie legs of whales & snakes.


There is no better love between 2 people than mutual respect for each other WT Young, 2002

Who gave anyone the authority to call me an authority on anything. WT Young, 1969

Since Evolution is only ~90% correct it should be thrown out and replaced by Creation which has even a lower % of correctness. W T Young, 2008


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rockondon
Member (Idle past 3217 days)
Posts: 40
Joined: 03-29-2010


Message 19 of 109 (554552)
04-08-2010 10:03 PM
Reply to: Message 15 by CosmicAtheist
04-08-2010 5:20 PM


This actually got me curious. Where can I read more on humans and tails? Such as studies involving cases where humans were born with true tails?


Here's a research study you might find interesting: http://www.ncbi.nlm.nih.gov/pubmed/7985392

Abstract
This study presents radiological and clinical findings in 70 patients with aplasia of caudal spinal segments and associated anomalies of the lower extremities and the inner organs. From a functional point of view 5 different types can be classified--unilateral hemi-aplasia, bilateral aplasia with or without sacral plateau, complex malformations of the caudal spine and medial spinal aplasia. Foot deformities and anomalies of the inner organs are common findings regardless to the extent of spinal aplasia, whereas popliteal webbing is only seen in cases with involvement of the lumbar spine. The lack of osseous junction between the spine and the pelvis leeds to a lumbopelvic kyphosis. Additionally the iliac wings are rotated in the frontal plane with the result of a narrow pelvic outlet and a change in the geometry of the hip joints. Embryologically all types of caudal spinal aplasia can be referred to a damage of the human tail bud. However, the term "Syndrome of Caudal Regression" is misleading; with respect to the presented results it is proposed to call this type of spinal malformation "Syndrome of Caudal Aplasia".

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Flyer75
Member (Idle past 715 days)
Posts: 242
From: Dayton, OH
Joined: 02-15-2010


(1)
Message 20 of 109 (554555)
04-08-2010 10:31 PM
Reply to: Message 10 by Flatland
04-08-2010 2:40 PM


Flatland writes:

Now can "the fall" explain the increase of human knowledge, the advancement of science and technology, the Renaissance, and the modern world? Why are we living so much better than our ancestors? According to the fall we should be getting worse. More epic fail from our resident creationist.

This is another thread that is way out of my league for me to discuss but your post is way out there.

I've never once heard this argument used by anybody. The Fall was a one time event that obviously affected everything but nowhere in the biblical account of the Fall is there mention of mankind digressing after this. Where is it mentioned anywhere in the Bible that man is digressing because of sin. If you believe the biblical account of the Fall and sin there isn't a progression of anything...in the end, the result is eternal life or eternal damnation, but nothing of a progressive digression of life, technology, or science.

Really the only thing that digressed was a moral order which was restored with the death and resurrection of Christ.


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CosmicAtheist
Member (Idle past 3183 days)
Posts: 31
From: Washington, USA
Joined: 04-07-2010


Message 21 of 109 (554563)
04-08-2010 11:57 PM
Reply to: Message 19 by rockondon
04-08-2010 10:03 PM


This is very interesting. How exactly do the differentiate from a true tail or pseudotail? And what would cause a pseudotail?

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Flatland
Junior Member (Idle past 2737 days)
Posts: 10
Joined: 01-30-2010


Message 22 of 109 (554565)
04-09-2010 12:10 AM
Reply to: Message 11 by Faith
04-08-2010 3:19 PM


quote:
Huh?

I said it explains DISEASE and DEATH, nothing else. The thread is about vestigial organs, not all of human history. Some creationists insist vestigial organs have a function, I see them as having lost former function, which is consistent with the Fall.


You're the one who brought up the "fall" not me. And no it does not explain death and disease at all. Not one bit.


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rockondon
Member (Idle past 3217 days)
Posts: 40
Joined: 03-29-2010


Message 23 of 109 (554574)
04-09-2010 2:57 AM
Reply to: Message 21 by CosmicAtheist
04-08-2010 11:57 PM


This is very interesting. How exactly do the differentiate from a true tail or pseudotail? And what would cause a pseudotail?

I fear this is only vaguely related to the subject and I prefer to stay on topic.

(in other words, I have no idea what the answers are to your questions )


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CosmicAtheist
Member (Idle past 3183 days)
Posts: 31
From: Washington, USA
Joined: 04-07-2010


Message 24 of 109 (554575)
04-09-2010 3:04 AM
Reply to: Message 23 by rockondon
04-09-2010 2:57 AM


Heh fair enough. Perhaps for another thread in the future if the curiosity ever gets the better of me.

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Dr Jack
Member (Idle past 397 days)
Posts: 3507
From: Leicester, England
Joined: 07-14-2003


Message 25 of 109 (554581)
04-09-2010 4:49 AM
Reply to: Message 5 by dwise1
04-08-2010 10:38 AM


In this case, they present "vestigial" as meaning "having no function" whereas the more proper meaning is that it no longer has its original purpose.

I must disagree. From the course on evolution I'm currently studying:

quote:
Vestigial features, structures, biochemical pathways or behaviours are not currently adaptive, at least not in free living stages, although they may facilitate embryonic development

By your definition, the bones of the ear are vestigial jaws, birds wings are vestigial legs, legs themselves are vestigial fins, and so on - that's not right.


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Replies to this message:
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Jumped Up Chimpanzee
Member (Idle past 3234 days)
Posts: 572
From: UK
Joined: 10-22-2009


Message 26 of 109 (554623)
04-09-2010 10:39 AM
Reply to: Message 12 by Kitsune
04-08-2010 3:41 PM


A creationist might, in turn, argue that it makes no sense for humans to "keep" the appendix when it so easily gets inflamed and bursts -- surely natural selection should have ensured that it disappeared entirely? (It's rare in my experience for a creationist to know enough about evolution to construct such an argument but it's a hypothetical possibility.)

The simple answer is evolution doesn't have any "sense". Evolution doesn't make cognitive decisions. Evolution does not step in and cut off unnecessary organs in an instant.

In order for the human species to lose any organ, it would first require at least one individual to be born with a mutation that meant it did not have that organ. It would then require that individual to survive to reproduce and pass on the new gene. It must then be a significant survival advantage not to have that particular organ. It would then require sufficient time for that gene to spread across the population.

Before all those things happen (which they may never do), it is entirely logical that an adaptation may occur, such as in this case where it is used to store bacteria. There is no predetermined outcome for what then happens to that organ. It may eventually (possibly in millions of years' time) be lost altogether, or it may remain for its existing adapted use, or it may adapt for another use entirely.


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Peepul
Member (Idle past 3310 days)
Posts: 206
Joined: 03-13-2009


Message 27 of 109 (554650)
04-09-2010 12:39 PM
Reply to: Message 25 by Dr Jack
04-09-2010 4:49 AM


quote:
--------------------------------------------------------------------------------
Vestigial features, structures, biochemical pathways or behaviours are not currently adaptive, at least not in free living stages, although they may facilitate embryonic development
--------------------------------------------------------------------------------

That's very interesting, Mr Jack.

Jerry Coyne doesn't agree with that view....

quote:
The lesson, though, goes deeper. The wings of the ostrich are a vestigial trait: a feature of a species that was an adaptation in its ancestors, but that has either lost its usefulness completely or, as in the ostrich, has been co-opted for new uses. Like all flightless birds, ostriches are descended from flying ancestors. We know this from both fossil evidence and from the pattern of ancestry that flightless birds carry in their DNA. But the wings, though still present, can no longer help the birds take flight to forage or escape predators and bothersome graduate students. Yet the wings are not useless—they've evolved new functions. They help the bird maintain balance, mate, and threaten its enemies.

http://jerrycoyne.uchicago.edu/excerpt.html

I agree with you that jaws should not be counted as vestigial ears, wings as vestigial legs etc - but I do think ostrich wings are vestigial.


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Dr Jack
Member (Idle past 397 days)
Posts: 3507
From: Leicester, England
Joined: 07-14-2003


Message 28 of 109 (554656)
04-09-2010 12:57 PM
Reply to: Message 27 by Peepul
04-09-2010 12:39 PM


Hmm, interesting point. One would naturally include Ostrich Wings as vestigial but they're also functional... hmm... I'm not sure what the best way through that is.

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rockondon
Member (Idle past 3217 days)
Posts: 40
Joined: 03-29-2010


Message 29 of 109 (554663)
04-09-2010 1:36 PM
Reply to: Message 25 by Dr Jack
04-09-2010 4:49 AM


Hi Mr Jack,
By your definition, the bones of the ear are vestigial jaws, birds wings are vestigial legs, legs themselves are vestigial fins, and so on - that's not right.

When a structure that was originally used for one purpose is modified for a new one, that's called an exaptation.
The distinction between a vestigial structure and an exaptation is sometimes vague, but generally speaking if the structure has a substantial new function and purpose, it should be considered an exaptation, not vestigial.

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Dr Jack
Member (Idle past 397 days)
Posts: 3507
From: Leicester, England
Joined: 07-14-2003


Message 30 of 109 (554667)
04-09-2010 1:46 PM
Reply to: Message 29 by rockondon
04-09-2010 1:36 PM


When a structure that was originally used for one purpose is modified for a new one, that's called an exaptation.
The distinction between a vestigial structure and an exaptation is sometimes vague, but generally speaking if the structure has a substantial new function and purpose, it should be considered an exaptation, not vestigial.

Yes, I realise that, Dwise's definition does not allow for it, however.


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