Understanding through Discussion


Welcome! You are not logged in. [ Login ]
EvC Forum active members: 85 (8984 total)
56 online now:
kjsimons, PaulK, Pressie, Tangle, vimesey (5 members, 51 visitors)
Newest Member: Jerry Johnson
Post Volume: Total: 877,396 Year: 9,144/23,288 Month: 159/1,544 Week: 434/518 Day: 14/88 Hour: 0/4


Thread  Details

Email This Thread
Newer Topic | Older Topic
  
Author Topic:   How creationism explains babies with tails
Granny Magda
Member
Posts: 2383
From: UK
Joined: 11-12-2007


Message 15 of 59 (596268)
12-14-2010 5:39 AM
Reply to: Message 11 by Aaron
12-14-2010 1:13 AM


Polydacty
Hi Aaron and welcome to EvC Forum!

My son was born with 7 toes on each foot.

Wow! That's pretty amazing. What is even more amazing though is that I can guess, with a reasonable chance of being correct, that you are of European extraction (extra digits are much more common amongst Europeans). If I'm right about that, then the chances are that your son has his extra digits on the "thumb/big toe" side of the feet (this is the most common position amongst Europeans, amongst Africans, the likelihood is that it is the other way around, on the "pinkie" side).

Polydacty is caused (usually) by a failure of the genes that control sonic hedgehog (not the cartoon character!). Sonic hedgehog is a signalling molecule that is vitally important in embryonic development. Amongst its many duties is that of telling the fingers where to grow, which way round to grow and so on. Mutations in the genes that keep sonic in check can lead to over-expression of certain traits, including fingers and toes.

What aspect of his evolutionary past was creeping up?

Given that even non-vertebrates have analogues of sonic hedgehog, an extremely ancient one.

Of course lots of mammals have varying numbers of digits. Pigs have four, camels two, elephants five and so on. Polydacty is equally able to affect them too, and by the same means as in humans (over-expression of sonic hedgehog), leading to multi-toed cats and so on (fifteen percent of the cats in Boston are polydactylous, with some having up to fifteen toes per foot). I would argue that this is strong evidence of inter-relatedness in all mammals, indeed, in all vertebrates.

Did our ape ancestors have extra digits too?

Doubtless.

I think you can read into genetic mutations what you want, but its not really proof of anything.

No? To me it seems like strong evidence of inter-relatedness. We use the same chemical pathways as cats and pigs, apes and horses in our developmental processes. There would be no reason for this if the Theory of Evolution were not true. Less closely related groups, like insects do not use sonic hedgehog, but analogous chemicals. This argues very strongly that a designer could have, if he so wished, used very different processes for different mammals. This does not appear to be the case. Instead, those creatures with a close evolutionary relationship to each other, use the most similar means of development.

Our developmental processes are amazing, but they are far from perfect. This is, of course, exactly what we would expect to see from the haphazard business of evolution. It is rather harder to square with the idea of an intelligent designer though.

Mutate and Survive


On two occasions I have been asked, – "Pray, Mr. Babbage, if you put into the machine wrong figures, will the right answers come out?" ... I am not able rightly to apprehend the kind of confusion of ideas that could provoke such a question. - Charles Babbage

This message is a reply to:
 Message 11 by Aaron, posted 12-14-2010 1:13 AM Aaron has responded

Replies to this message:
 Message 16 by Wounded King, posted 12-14-2010 9:51 AM Granny Magda has responded
 Message 19 by Aaron, posted 12-15-2010 2:31 AM Granny Magda has responded
 Message 20 by Aaron, posted 12-15-2010 2:38 AM Granny Magda has not yet responded

  
Granny Magda
Member
Posts: 2383
From: UK
Joined: 11-12-2007


Message 17 of 59 (596347)
12-14-2010 1:10 PM
Reply to: Message 16 by Wounded King
12-14-2010 9:51 AM


Re: Polydacty
Hi WK,

Okay, I got that bass ackwards. Clearly I'm not going to argue with you over molecular biology. Even I am not that stubborn.

My main point was simply that the ubiquity of the "hedgehog" signalling molecules point to an ancient evolutionary inter-relatedness between diverse animal groups.

Mutate and Survive


On two occasions I have been asked, – "Pray, Mr. Babbage, if you put into the machine wrong figures, will the right answers come out?" ... I am not able rightly to apprehend the kind of confusion of ideas that could provoke such a question. - Charles Babbage

This message is a reply to:
 Message 16 by Wounded King, posted 12-14-2010 9:51 AM Wounded King has not yet responded

  
Granny Magda
Member
Posts: 2383
From: UK
Joined: 11-12-2007


(1)
Message 21 of 59 (596505)
12-15-2010 10:57 AM
Reply to: Message 19 by Aaron
12-15-2010 2:31 AM


Re: Polydacty
Hi Aaron,

Exactly, these mutation have nothing to do with evolutionary ancestors. They are merely mutations in regulatory genes. Babies aren't born with tails because of a reversion to an ancestral ape state any more than babies born with Anencephaly - or lack of a spinal chord - are reverting back to a invertebrate ancestor. It's just a genetic mixup, that's all.

I pretty much agree with you. I do however think that such developmental oddities shine a light on how evolution can work. What, after all is a tail? It's just an extension of the spine. All that need be done to create a tail is to add more vertebrae. But that also means that all that need happen for a species to permanently lose its tail is for the regulatory genes to enforce fewer vertebrae. Our bodies are almost modular in this way and it only takes a minor change to cause something like the loss of a tail.

So in summary, human tails do not necessarily reflect a "reversion" to an atavistic state but they do reveal how such a change could have taken place. They do reveal that such changes are, in principle, possible, so they do touch on the ToE.

The problem with this logic is an assumption that if everything was designed, the designer wouldn't have repeated elements in each creature. You imply that better proof of a designer is if each creature employed unique metabolic pathways, had DNA composed of different types base pairs, or had unique methods of reading DNA.

No, that's not what I mean.

What I'm getting at is that if you take closely related creatures like humans/chimps or fruit flies/mosquitoes, you will find far greater similarities in their regulatory chemicals than between human/fruit fly for example. Why need this be true if they are designed from scratch? Why not a human with insect signalling proteins? Why not mix and match, across the board? This is what human designers do after all. But no, we see that variation takes place within a framework of evolutionary relatedness. That seems likes a strange and highly dishonest choice for a deity to take. Why would God ape evolution? Doesn't he want us to believe in him?

This is assuming 2 things:

1.) that an intelligent designer must create creatures that are completely perfect and can life forever - and has no reason to do otherwise

Yes. You are absolutely right. You must assume that the designer wanted his creations to suffer and die. Nice.

2.) that the imperfections we see in development were part of the original design

Are you saying that they evolved? Or are you going to start dragging ancient myth into this?

Mutate and Survive


On two occasions I have been asked, – "Pray, Mr. Babbage, if you put into the machine wrong figures, will the right answers come out?" ... I am not able rightly to apprehend the kind of confusion of ideas that could provoke such a question. - Charles Babbage

This message is a reply to:
 Message 19 by Aaron, posted 12-15-2010 2:31 AM Aaron has responded

Replies to this message:
 Message 22 by Minnemooseus, posted 12-15-2010 8:29 PM Granny Magda has responded
 Message 23 by Aaron, posted 12-16-2010 1:28 AM Granny Magda has responded

  
Granny Magda
Member
Posts: 2383
From: UK
Joined: 11-12-2007


Message 25 of 59 (596665)
12-16-2010 12:16 PM
Reply to: Message 22 by Minnemooseus
12-15-2010 8:29 PM


Re: We're back to considerations of human tails
Hi Moose,

So, is this recent discussion severely undermining AA's message 1 position?

I dunno, maybe a little. But I can only speak for my personal opinion and as you can tell from WK's correction above, I'm no expert.

Personally, I don't think that babies being born with tails is quite the evolutionary give-away that it appears to be at first glance. I think that whilst an atavistic explanation might be correct, it might be a simple developmental fluke that creates simple tails, not ancient traits being re-expressed. Even the more complex tails mentioned by Apostate Abe might have a developmental origin, as the result of embryonic tails being retained, rather than lost during early development. I think that it is the embryonic tail itself though that is most difficult for creationists to explain.

Creationists should take a close look at the embryo photo in Message 1. That human embryo clearly has a tail. It is not some faked drawing, but a picture of a human tail. It's there because we are tetrapods and tails are part of the tetrapod body plan. That tail most certainly IS an evolutionary hold-over. Whether a child can be born with it or not is interesting, but it isn't really the point. The insurmountable problem for creationists is the presence of an embryonic tail in the first place.

I would be curious to hear how Aaron, JBR or any other members with creationist sympathies explain the presence of tails in human embryos.

Mutate and Survive


On two occasions I have been asked, – "Pray, Mr. Babbage, if you put into the machine wrong figures, will the right answers come out?" ... I am not able rightly to apprehend the kind of confusion of ideas that could provoke such a question. - Charles Babbage

This message is a reply to:
 Message 22 by Minnemooseus, posted 12-15-2010 8:29 PM Minnemooseus has acknowledged this reply

Replies to this message:
 Message 28 by Aaron, posted 12-21-2010 1:55 AM Granny Magda has acknowledged this reply

  
Granny Magda
Member
Posts: 2383
From: UK
Joined: 11-12-2007


Message 26 of 59 (596670)
12-16-2010 12:51 PM
Reply to: Message 23 by Aaron
12-16-2010 1:28 AM


Re: Polydacty
Hi Aaron,

Actually, in the realm of human engineering, similar looking cars will use many of the same design and mechanical elements - they are necessary to create a functioning car. A toaster, however, will have far fewer related components. Components determine function. A toaster that is made with a manifold, spark plugs, and fuel filter won't be a handy toaster.

Yes, but what a designer making cars can do differs from what evolution is able to do.

A designer can take an advance from one car (say a catalytic converter) and introduce to other "unrelated" cars. It doesn't matter that the converter was originally fitted in one type of car, it can be isolated from the rest of the vehicle and introduced into all sorts of cars, from many different "lineages" (i.e. manufacturers). An advance originating in a Jaguar can, in principle, be applied in a Rolls Royce or a Ferrari.

Evolution cannot do this, at least not in complex multicellular organisms. An evolutionary advance in a mammal cannot be then applied to birds or bugs. Those groups are reproductively isolated from the mammalian line and thus, they cannot be party to its novel mutations. Those groups would have to evolve the same advance independently.

So, if we are designed, why do we not see advances being applied across the evolutionary divides? Why do we only see the mammalian hedgehog homologues in mammals? A designer could easily have put them in insects. He did not. Mammals have mammalian hedgehog, insects have their own version. Why not mix-and-match, the way a designer would? Why do it exactly the way evolution would do it?

Granny Magda writes:

Why would God ape evolution?

Aaron writes:

Please rephrase this, I'm not sure what you are saying.

If he did design us, God seems to have gone out of his way to make us look as if we evolved. Embryonic tails, homologous yet distinct developmental signalling molecules, clearly observable means of tiny random mutations creating major phylogenetic change... This all looks very much like an evolved system. It looks like a very capricious way for a wise and benevolent designer to behave however. It's almost as if he were trying to trick us into believing that he wasn't there, that evolution was capable of diversifying life all on its own.

Or perhaps evolution really is capable of diversifying life, all on its own, no designer needed. It would seem the more parsimonious solution.

By the way, what is your explanation for the presence of a tail in the human embryo?

Suffering isn't a universal property of life - but even if it were - that's an interesting topic from a theological standpoint that would take this discussion in a whole new direction.

I think that "interesting" is rather an understatement. "Horrifying" would be my choice. But, you're right, this isn't really central to the topic. so I will simply say this of your car analogy; for it to work, the father would have to withhold the Audi until after his son died. That is a much fairer comparison to what you are really intimating. And yes, I would consider that guy a crappy father.

Evolved... devolved... I'm okay with that.

There's really no such thing as "devolved". Evolution does not have a pre-determined direction, and thus cannot be said to be in reverse gear.

Our DNA has been mutating and breaking down for a long time. Genetic disease is on the rise, not on the decline.

Yes, as I thought. You are attempting to drag Adam and Eve into a discussion about biology. Do you really believe that your son was born with extra toes because one of his ancient ancestors ate some fruit? And you're okay with that?

By the way, the ToE does not predict that genetic disease ought to decline. Further, do you want to bet that genetic disease is on the rise because we know of more genetic diseases, year on year, and we know more about them year on year? It could hardly do anything other than rise could it?

Mutate and Survive


On two occasions I have been asked, – "Pray, Mr. Babbage, if you put into the machine wrong figures, will the right answers come out?" ... I am not able rightly to apprehend the kind of confusion of ideas that could provoke such a question. - Charles Babbage

This message is a reply to:
 Message 23 by Aaron, posted 12-16-2010 1:28 AM Aaron has responded

Replies to this message:
 Message 27 by Aaron, posted 12-21-2010 1:40 AM Granny Magda has responded

  
Granny Magda
Member
Posts: 2383
From: UK
Joined: 11-12-2007


Message 29 of 59 (597379)
12-21-2010 8:06 AM
Reply to: Message 27 by Aaron
12-21-2010 1:40 AM


How Creationism Explains Human Tails (It Doesn't)
Hi Aaron,

Why do you think a designer would put a mammalian protein in an insect?

Well apart from anything else, it would stop us from looking quite so evolved. It seems perverse that God should create life, only to go to an effort to make it look as though it evolved and that he was never involved. That seems dishonest.

Do you think there are many proteins that can be swapped back and forth between various creatures without causing harm?

This is God we're talking about isn't it? Why do you suddenly seek to place arbitrary limits upon his capabilities?

Why diverge from the common ancestor when there is no need?

In such a vast span of evolutionary time as back to the divergence of the common ancestors of humans and insects, genetic drift alone would be guaranteed to cause some divergence, even if there were no adaptive advantage (and I would expect that there was).

This is really a much more difficult question for your position. Why would God design in the style of evolution, when evolution is not true?

Why do humans and chimps only share about 30% of identical protein structures if those proteins perform more or less the same role both each species? What pressure would cause humans to diverge from the protein structure of the common ancestor if the protein performs the same role?

According to Wiki;

quote:
Typical human and chimp homologs of proteins differ in only an average of two amino acids. About 30 percent of all human proteins are identical in sequence to the corresponding chimp protein. As mentioned above, gene duplications are a major source of differences between human and chimp genetic material, with about 2.7 percent of the genome now representing differences having been produced by gene duplications or deletions during approximately 6 million years[4] since humans and chimps diverged from their common evolutionary ancestor. The comparable variation within human populations is 0.5 percent.

So the 30% figure is misleading when mentioned alone, as it fails to note that the average human/chimp protein comparison differs by only two amino acids.

The answer to your question appears to be that gene duplications and deletions have caused the human/chimp genomes to diverge. The article also notes several cases where strong positive selection appears to have taken place in the story of human/chimp divergence.

All of this is absolutely what we would expect from evolution.

For God to do this can only be described as a deliberate deception, tricking us into believing in evolution.

Granny Magda writes:

By the way, what is your explanation for the presence of a tail in the human embryo?

Aaron writes:

That might be a better question for a developmental biologist.

No, in this thread, it is a question for creationists. Developmental biologists already have an explanation. I am interested in the creationist version.

What purpose does the tail serve in the embryo's development?

None.

In the early stages of brain development, a group of cells help establish boundaries until the proper cells are available - and later the temporary cells disappear. Similarly, the tail end may serve as a place holder until the rest of the body grows around it.

But that is an extremely weak argument. There is something that grows in the place of those cells; the brain. There is no equivalent for the embryonic tail. It is simply reabsorbed. Nothing grows in its place. This is highly implausible.

Let's be clear here; you have no real explanation for the embryonic tail. The creationist position cannot explain this feature.

And again, it is a perverse choice for God to create such a clear piece of evidence for evolution, especially when t serves no purpose.

Perhaps from an atheistic view of death, the father would be crummy - because death would be dark nonthingness for the son. However, any theistic view of death portrays it as a "graduation" of sorts into a better existence. In this case, the son gets the reward for his trials after "graduation."

But of course, you have no evidence whatsoever for the afterlife, so this comes across as something of a poor deal.

I agree - when a baby is born with a tail, it is a far cry from the tail of a monkey.

No! This is wrong!

The little stubby tails that are most common bear little comparison, but the rarer, more sophisticated tails most certainly do. They have non-fused vertebrae, muscle, skin, nerves, sebaceous glands... How much more like a tail do you want them to be? These tails are essentially the embryonic tail retained into infancy. They are not simply flukes. They are even inheritable.

You can explain these by resorting to the embryonic tail of course, but that still leaves you with the task of explaining the embryonic tail itself; something that you do not seem to be able to do.

Anybody know if chimps or gorillas are ever born with accidental tails?

I couldn't find anything, but I would predict that it is possible. You have to remember though, that these tails are extremely rare in humans, and we have a vast population. The great apes have incredibly tiny populations, so there are far fewer opportunities for such births to occur.

Anyhow, Haeckle's theory of the Biogenetic Law is largely debunked.

As a law, set in stone, yes. But as a general trend, it is still true. This is an example of embryonic development following in evolution's path. It need not happen in every case, but in this case, it does.

If you disagree, you need only provide a creationist rationale for human tails.

Mutate and Survive

Edited by Granny Magda, : No reason given.


On two occasions I have been asked, – "Pray, Mr. Babbage, if you put into the machine wrong figures, will the right answers come out?" ... I am not able rightly to apprehend the kind of confusion of ideas that could provoke such a question. - Charles Babbage

This message is a reply to:
 Message 27 by Aaron, posted 12-21-2010 1:40 AM Aaron has responded

Replies to this message:
 Message 32 by Aaron, posted 12-30-2010 2:59 AM Granny Magda has responded

  
Granny Magda
Member
Posts: 2383
From: UK
Joined: 11-12-2007


Message 33 of 59 (598304)
12-30-2010 8:30 AM
Reply to: Message 32 by Aaron
12-30-2010 2:59 AM


Re: How Creationism Explains Human Tails (It Doesn't)
Hi Aaron,

There would be those who would find patterns to support their position no matter what this world looked like.

And we call these people "creationists".

I'm sure you've heard it a million times already, but the evidence for common ancestry could logically be used as evidence for common design.

But they don't resemble design. They don't do the thigns that a designer can do. Keeping evolutionary changes strictly limited to those taxa in which they originated cannot be used as evidence for anything other than evolution. This is simply a typical example of creationist denial of reality.

What you are suggesting about God's capabilities is not in line with the historic Christian position of God. God has limits. He can't operate in logically contradictory means. He can't make you exist and not-exist at the same time in the same place in the same way. He can't make a square circle. These limits certainly aren't arbitrary.

Agreed, but we're not talking about pure logic. We're talking about physical stuff, about the brass tacks of biology. There is no reason why God, if he can create complex biology, can't produce it however he likes. Certainly he could have created in such a way that did not so perfectly replicate evolution. Face it Aaron, your only option here is to believe in a liar god.

If God has decided that protein A B and C will lead to the formation of a backbone - He can't put those same proteins in the same way in an insect and have them lead to the formation of an eye.

Again, this is not a logical impossibility and the close homologies between mammalian and insect signalling molecules gives the lie to this.

This study notes 80% difference between human and chimp proteins.

And your point is? Because this appears irrelevant.

I'll let you know when I'm making a statement for the whole of creationism... Until then - I reserve the right to speculate and make mistakes.

Sure. However, this board remains open to all and there has, so far, been no robust response from the creationist contingent.

Creationism cannot explain the human embryonic tail.

There are a number of temporary structures in fetal development that aren't replaced with an identical structure, such as the pronephric kidney and pharyngeal arches. Both serve temporary functions and both are later dissolved.

But the tail isn't replaced with anything at all! It just dwindles away, leaving the coccyx. You are clearly desperate and grasping at straws.

I read someone suggest that the embryonic tail helps ensure there is adequate blood supply to the developing leg buds.

Great. Bring that evidence then. Unless of course, they were just grasping at straws as well.

The tail may also serve as a cell inducer which provides signals to spurn the development of other tissues and structures. This is known to be the case in other organisms such as chickens and frogs whose tail portion helps induce the growth of some of the hind portions. Perhaps the human tail does the same thing and retracts slightly when its job is finished.

Great. Bring that evidence. Bring it without the word "perhaps" in it so prominently. You can wonder "what if?" all day, but in the absence of any evidence for these claims, you are whistling in the dark.

The death of the final few vertebrae in the embryonic tail may just be part of the process of forming the coccyx.

This completely misses the point. The tail becomes the coccyx yes, but why a tail in the first place? Why does your all-knowing god not simply design a tail? Why does he seek to deceive us by achieving his design through what looks so clearly like an evolutionary atavism?

Similarly, there are interdigital cells that must die during development for our toes and fingers to form correctly.

Oh look! Another evolutionary atavism! I guess that must prove creationism true... ... ... wait...

You have given it a good go, but the truth is that you have no explanation for the human embryonic tail. No creationist does. Evolution on the other hand, explains it easily; it is simply part of the basic tetrapod body plan, developed millions of years ago in our fishy ancestors.

Mutate and Survive


On two occasions I have been asked, – "Pray, Mr. Babbage, if you put into the machine wrong figures, will the right answers come out?" ... I am not able rightly to apprehend the kind of confusion of ideas that could provoke such a question. - Charles Babbage

This message is a reply to:
 Message 32 by Aaron, posted 12-30-2010 2:59 AM Aaron has responded

Replies to this message:
 Message 37 by Aaron, posted 01-06-2011 2:53 AM Granny Magda has responded

  
Granny Magda
Member
Posts: 2383
From: UK
Joined: 11-12-2007


Message 40 of 59 (599292)
01-06-2011 11:58 AM
Reply to: Message 37 by Aaron
01-06-2011 2:53 AM


Re: How Creationism Explains Human Tails (It Doesn't)
Hi again Aaron,

Granny writes:

Keeping evolutionary changes strictly limited to those taxa in which they originated cannot be used as evidence for anything other than evolution.

Aaron writes:

I'm not tracking with your thought here - please give an example.

Why don't we see eagle-like eyes in humans? Or a dog-like sense of smell? These are both good designs, so why are they kept strictly to separate lineages? Why do only birds of prey have those eyes? Why no other species? Why not give chimps the same smell capabilities as dogs? They sure could use it. But no, once again, these features are exclusive to the group in which they emerge.

This is exactly what we would expect from evolution, where reproductive isolation between species prevents these traits from being shared amongst a wider gene pool. It is not what we would expect from a designer, who could swap traits around, mixing and matching, just as modern engineers do. We never see this in biology. In cases where the same traits appear in different taxa, they are always traceable to a common ancestor. They show divergence, just as in the case of human and insect sonic hedgehog molecules.

If you could show me an example of a trait from one species that also appeared, unaltered, in another, unrelated species, without resorting to known mechanisms such as hybridisation and HGT, I would have to hail it as strong evidence for design in biology. No such example has been found, not is it likely to be found.

With creatures that look similar, there's bound to be similar genetic makeup.

No. Under a design paradigm, this is false. There is no reason why a designer, especially a divine one, could not make similar looking creatures genetically diverse. He is the designer. He is in at the drawing board. He sets the rules. There are no limits upon what he can and cannot design.

Even in an evolutionary model, convergent evolution can and does produce very similar looking structures in different lineages, so your position here cannot be correct.

I'm still not sure what you think the kingdoms of life should look like in order for it to look designed.

I would expect to see good ideas - like the human brain or the dog's sense of smell - reused in other ancestral lineages, without signs of evolutionary common ancestry. We do not see this.

Alternatively, we might see one system being used for development in mammals, with a completely separate system in place in insects. If they are independently designed then the two systems need not resemble each other at all. Why would an honest god feel the need to make them look so alike in the first place?

God can't break those rules and use a sequence of proteins to perform one function in a mammal and another function in an insect.

Yes he can. He wrote the rules according to your model. There is no reason why he could not have designed life in a more modular fashion, the way an intelligent designer would have done. Instead he chose not to do this and to create every living thing just as if it had been evolved.

You keep saying that God can't break the rules; he wrote the rules. He can do whatever he likes.

You are already settled on your answer - yet how many creationists have you polled?

Please Aaron, this is a debate site. I am taking a debate position. My contention is that creationism cannot explain the embryonic tail. It is up to any creationist respondent to this thread to prove me wrong. That's not indicative of a closed mind on my part, it's just how a debate works. I have to take a position.

Find a creationist biologist and maybe he/she can give you the answer you are looking for.

If any want to respond to this thread, they are welcome to do so. But, as Coragyps notes above, the phrase "creationist biologist" is close to being an oxymoron. Knowledge of biology tends to act as a solvent against creationist dogma.

Are you asking why we have a coccyx? I don't quite grasp the point you are trying to make here.

No. I'm simply asking why a tail or tail-like structure at all? You claim the embryonic tail has a function (but you don't know what it is). What I want to know is why any sane deity would answer that functional need with a tail. Why a tail? Of all things! It might do whatever developmental job needs to be done, but it sure looks suspicious. It looks evolved. It is almost unmistakably evolved. Why create such a dead-ringer for an evolutionary atavism? Why make us look evolved when we are not? And how could a benevolent god have done something so dishonest?

I emailed some developmental biologists. I'll give you a quote from one of the responders:

I appreciate the effort you've gone to Aaron, but without some kind of attribution, that quote is worthless. Was this from a creationist source? Or... y'know.. an actual biologist?

I beg to differ from your quoted source. A structure that springs up, does nothing apparent and then dies is entirely compatible with lack of function. If anyone wants to claim a function for it, they need to demonstrate it.

All your speculation that the embryonic tail serves no function is only that - speculation rooted in an evolutionary framework.

One could say the same of your claim that it must serve a function, save that evolution is one of the best evidenced theories in existence. The "evolutionary framework" you so dislike is grounded in a wealth of evidence. What support can creationism claim? A dusty old set of myths, that's all.

Furthermore, as long as the tail is viewed as a mere evolutionary remnant - why would anyone bother testing to see what it does ?

Well that's an interesting question; why don't these creationist biologists do the research? It might be difficult, but finding a non-evolutionary explanation would be a big boost to creationist arguments. So why don't they do it? It seems to me that creationists are not keen to do their own research, preferring instead to merely complain about other peoples work.

And that atavism would be the shadow of our 18 fingered ancestor?

No, that would be our lobe-finned fish ancestor. Tetrapod limbs started out as fins. They appear to recapitulate that in the womb. This is another odd design choice for an honest god. Makes sense for a liar god though. Or a total lack of gods.

Mutate and Survive

Edited by Granny Magda, : No reason given.

Edited by Granny Magda, : No reason given.


On two occasions I have been asked, – "Pray, Mr. Babbage, if you put into the machine wrong figures, will the right answers come out?" ... I am not able rightly to apprehend the kind of confusion of ideas that could provoke such a question. - Charles Babbage

This message is a reply to:
 Message 37 by Aaron, posted 01-06-2011 2:53 AM Aaron has responded

Replies to this message:
 Message 45 by Aaron, posted 01-15-2011 2:59 AM Granny Magda has responded

  
Granny Magda
Member
Posts: 2383
From: UK
Joined: 11-12-2007


Message 48 of 59 (600681)
01-16-2011 10:04 AM
Reply to: Message 45 by Aaron
01-15-2011 2:59 AM


Re: How Creationism Explains Human Tails (It Doesn't)
Hi Aaron,

Silk producing abilities have evolved convergently in spiders, worms, mollusks, and some fish. Did they all get if from the common ancestor?

a) Fish? I presume you mean the slimy protein filaments of the hagfish? I do not think this is a fair comparison to true silk. Just try making a carpet out of hagfish slime.

b) The silks employed by different species are different, chemically. If all these species, divided into disparate groups as they are, all had exactly the same silk, it would be impressive. But they don't.

By the way, did you know that spider silks are different from each other? And that they fall into a nested hierarchy? It's an odd design choice to make it look so evolved... but I guess you're used to that by now.

The presence of the poison tetrodotoxin was evolved convergently in pufferfish, the blue-ringed octopus, and the California newt. Is that the kind of example you're looking for?

No. This sounds like a really quite impressive example, but it's really not, since the tetradotoxin is not actually produced by those critters at all. It's produced by bacteria, to which the larger creatures play host. They have evolved this feature as a response to exposure to the toxic bacteria in their environment (you''ll note that all of these venomous creatures are aquatic; terrestrial creatures would not be exposed to the bacteria).

So no, sorry, I don't find either of those examples convincing.

I'm sure you could pick out developing and temporary structures that resemble parts of non-related animals.

Well okay. If you're so sure, please show us an example of an embryonic structure that resembles a "non-related" creature as clearly as the human embryonic tail resembles that of tailed primates.

The quote was from Kerry Kornfeld, Professor of Developmental Biology,Co-Director, Program in Developmental Biology Washington University School of Medicine - if that makes a difference. Feel free to disagree with him. I don't know who the guy is, I just picked him at random.

Okay. Firstly, Kornfeld is the author of a large number of papers about evolution, so he is only going to support your ideas so far. I wonder, did you mention creationism in your email to him? Did you specifically mention that your idea was intended as an alternative to atavism in the embryo and to evolution as a whole?

I do disagree with him in this context, I have to say. Mainly because I have heard this particular excuse before;

Evo; "This structure makes no sense from a design point of view."

Creo; "Well it will! It must have a function, as yet undiscovered."

Evo; "What function"

Creo; "I don't know, but it must have one."

Evo; "How do you know it has a function?"

Creo; "Because if it doesn't, my theology is screwed, so... it must!"

And so on... Every time creationists are shown a clear example of bad "design" I get the response that there must be some undiscovered function. This is basically an excuse, a theological IOU. I don't find it convincing, especially as we already have an explanation for these matters, it's just that you find that explanation unpalatable for religious reasons. The only reason you have to suppose a function for the embryonic tail is to get yourself out of a theological hole and that is just not science.

Forgive me, but I intend to stick with the extremely robust explanation provided for us by the ToE, above creationist excuses and empty promises.

Mutate and Survive

Edited by Granny Magda, : No reason given.


On two occasions I have been asked, – "Pray, Mr. Babbage, if you put into the machine wrong figures, will the right answers come out?" ... I am not able rightly to apprehend the kind of confusion of ideas that could provoke such a question. - Charles Babbage

This message is a reply to:
 Message 45 by Aaron, posted 01-15-2011 2:59 AM Aaron has responded

Replies to this message:
 Message 53 by Aaron, posted 01-24-2011 9:15 PM Granny Magda has not yet responded

  
Newer Topic | Older Topic
Jump to:


Copyright 2001-2018 by EvC Forum, All Rights Reserved

™ Version 4.0 Beta
Innovative software from Qwixotic © 2020