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Dolphins' are back on Earth

Posted: Fri Nov 10, 2006 4:34 am
by angel

Posted: Fri Nov 10, 2006 3:08 pm
by Gman
I'm not sure of associating these extra fins to legs is a good analogy since dolphins use their pectoral flippers mainly to steer and, with the help of the flukes, to stop...

Quote AIG: "It should be noted that the pectoral fins or flippers of the dolphin contain bones that are homologous (similar) to those of the human arm and hand (as well as the forelimbs of other mammals). The pectoral fin of the dolphin, for example, contains a short bone similar to the humerus (upper arm bone) of land dwelling mammals which is attached by a ball socket type joint to a scapula (shoulder blade). The humerus in turn articulates with a pair of side-by-side short bones similar to the radius and ulna (lower arm bones) of other mammals. Finally, the fin contains small bones roughly comparable to wrist bones and linear rows of bones that superficially resemble fingers.

But there are significant differences in both structure and function between the fin bones of dolphins and the limb bones of terrestrial mammals. First, dolphins do not actually swim with their pectoral fins (this is largely a function of the tail flukes) but mostly use them to steer and to assist the flukes in stopping. Dolphins do not have a movable elbow joint and hold their pectoral fins rather rigidly out from the body. Their only mobile joint is at the shoulder. While this is an effective arrangement for simple steering and stopping it is unsuitable for walking or grasping.

The dolphin, like nearly all vertebrates, has five fingers or digits but in the dolphin there are many bones that make up the “fingers” (fin rays) rather than the typical sequence of three bones seen in the digits of humans and many other mammals. This serves to greatly lengthen the fin.

While cetaceans (dolphins, porpoises, and whales) lack hind limbs, they have pelvic bones that differ in males and females and appear to support the reproductive organs. Whether they also have rudimentary femurs and other leg bones is less certain. For evidence of whale “legs,” many evolutionists cite a paper published by Struthers in 1881 which purports to describe a rudimentary “femur” in the adult Greenland Right-Whale (Balaena mysticetus). Other more recent publications suggest embryonic stages in cetaceans that resemble limb bones.

Homologous structures are seen throughout the vertebrate phyla—but as creationists have pointed out so many times, the homology argument does not support evolution, but rather a common designer. There are many problems with the homology argument as used by evolutionists. For example, the rudimentary male mammary gland and nipple are clearly homologous to those of the female, but they are not taken as evidence that males once nursed their young.

Homology tells us something about embryology—not about evolution. It is unfortunate that reporters and others often jump to conclusions before real science can be done to provide proper conclusions. Evolutionists are constantly looking for transitional forms, grasping at straws—or even fins—for evidence that just isn't there."

Source: http://www.answersingenesis.org/docs200 ... n-legs.asp

Posted: Sat Nov 11, 2006 2:30 pm
by BGoodForGoodSake
I don't think that this would be good evidence for terrestrial origins.

Posted: Tue Nov 14, 2006 1:30 am
by angel
Sorry guys as usual I was in a hurry and I posted the link without comments. Thanks to you for replying, anyway.

I was surprised by your answers... Are we still discussing whether dolphins share a common ancestor with terrestrial mammals?
Or you are just commenting about possibility of using the link as a further evidence for that?

Gman, as far as I understand 'homology argument' is mainly concerned with homology of structures and very little with functional homology.
(Our toe is functionally different from monkey's toe, not for that we can conclude that we share no common ancestor with monkeys, I hope.)
Your list of arguments is very interesting even it basically recognized structural homology and discuss functional homology.
It seems to me it *supports* common ancestor (or if you like common designer, though a lazy and unimmaginative one).


BGoodForGoodSake
I don't think that this would be good evidence for terrestrial origins.
I didn't know that further evidences were necessary.

My original goal was to discuss the possibility of providing new organs by random mutations (which are being discussed in a parallel thread right now).

I think the interesting way of looking at the link is the following.

You can consider obvious that once dolphins were terrestrial. In that case it is obvious that their DNA still remembers the typical mammals structures.
These characters have been suppressed by selection (which means they are still there as 'junk DNA'), and now they have re-emerged by a small random mutation which forced the genetic material to express itself again. Nothing too strange with it.

Or you can consider dolphins as designed. In that sense there is no apparent reason for a designer to hide coding for legs which are not expressed. (Ok, here I am not discussing designer right to do what it pleases, I am just asking for a good reason for it to do such a thing).
Under this viewpoint there are two possibilities:

FIRST: the designer did designed legs for dolphins and forced that character to hide. Going this way it is clear that we shall soon obtain an ID theory which is completely and absolutely un-observable and un-distinguishable for evolution, in principle.

SECOND: the designer did not encoded for delphins legs. Then either they emerged by random mutations or by designer action.


Is there anyone who believes it to be an istance of designer action? If so, I stress it would be the first instance of designer's action ever detected.

If "legs" emerged from nothing by random mutations... well how should I go on claiming that random mutations cannot produce NEW ORGANS.

Imagine that dolphins would have an advantage by trying to be back on earth ('cos oceans are too polluted and they would not find too strong competition on the ground- I don't know- think most ground animals were just extincted by an asteroid).
In that case that mutation would be quite beneficial. Imagine that particular dolphin could spend some very short time on the shore eating for some vegetables (or hunt for some small animal on the shore).
This could allow it to reproduce (maybe better than regualr dolphins).
In a few generations a small percentage of the population will have four fins. These dolphins would live near the shore (since they probably depend on it to survive). They become a separate population and interbreed. This would enforce the mutation and soon (as they accumulate their mutations) they would become a different specimen of dolphins.
Then who knows how selection can effect their phenotype?
In the end they could become a new guy, who shares a common ancestor with ocean dolphins despite they are four legged.


Sorry guys, it may be unaccurate but I fail to see why I should not consider it roughly possible.

Posted: Tue Nov 14, 2006 7:10 pm
by Gman
angel wrote:Gman, as far as I understand 'homology argument' is mainly concerned with homology of structures and very little with functional homology. (Our toe is functionally different from monkey's toe, not for that we can conclude that we share no common ancestor with monkeys, I hope.) Your list of arguments is very interesting even it basically recognized structural homology and discuss functional homology.
Can you show me the reference where evolution is mainly concerned with homology of structures and very little with functional homology? I would assume that the structure would define the function or visa versa.
angel wrote:It seems to me it *supports* common ancestor (or if you like common designer, though a lazy and unimmaginative one).
I don't see how the "common designer" approach would be a lazy and unimaginative one. Please explain...

Posted: Thu Nov 16, 2006 4:20 am
by angel
Can you show me the reference where evolution is mainly concerned with homology of structures and very little with functional homology? I would assume that the structure would define the function or visa versa.
Dear GMan,
I said "homology argument" is about structural similarities, not that EVOLUTION is about structural similarities.
However, if you consider functional similarities it is very difficult to distinguish between evolution from common ancestor and convergent evolution.
I don't think there are very much instances of serious scientific discussions about functionality in evolution.
(According to functional arguments our toe is very different from monkeys toe. Should I conclude that we are stricter relatives of camaleon than with monkeys since its toe is functionally closer to our toe than the monkeys' one?)
Nowadays evolution is concerned with genetic similarities. Both structural and functional homologies are just considered as a manifestation of genotypes similarities which are in turn a manifestation of genetic homology. It is only in terms of genetics that you can define proximity among different specimen.
I mean any web search restricted to biology journals will show that this is, correct or wrong, the current reseach trend in biology.
Feel free to post links to contradict me.



I don't see how the "common designer" approach would be a lazy and unimaginative one. Please explain...
It was mainly a joke. However, not completely...
There are a lot of things that the designer did not do.
For example it did not seem to created crabs ables to perform photosyntesis.
It did not equip gorillas and humans with any viral insertion which was not shared by chimps as well.
It did not design any reptiles which breeds as mammals.
It did not insert genes in reptiles which are identical (including synonimous mutations) to the corresponding genes in mammals.

Each of these things could be easily designed if all specimens were created, ups.. sorry I meant designed, independently of each other.
Evolution explains why such things do not show up. ID does not if not by resorting to thye goddidit argument.
That is a fact.

BTW you did not anwered my question. Are we still discussing if dolphins share a common ancestor with ground mammals?
I'm not asking about the evolution being run by random mutations and selection. I'm just asking if you agree that they share a common ancestor.

Posted: Thu Nov 16, 2006 9:54 pm
by Gman
angel wrote:I don't think there are very much instances of serious scientific discussions about functionality in evolution.
Dear Angel,

I'm sure you have heard about analogies in evolution.. Evolutionists have separated most supposed examples of homology into two types... Analogy and homology. "This division is based on a distinction between similarity due to common ancestry, or homology, and resemblance which is due solely to similarity of FUNCTION, called analogy."

Source: http://www.answersingenesis.org/tj/v15/i1/homology.asp
angel wrote:It was mainly a joke. However, not completely...
There are a lot of things that the designer did not do.
For example it did not seem to created crabs ables to perform photosyntesis.
It did not equip gorillas and humans with any viral insertion which was not shared by chimps as well.
It did not design any reptiles which breeds as mammals.
It did not insert genes in reptiles which are identical (including synonimous mutations) to the corresponding genes in mammals.

Each of these things could be easily designed if all specimens were created, ups.. sorry I meant designed, independently of each other.
Evolution explains why such things do not show up. ID does not if not by resorting to thye goddidit argument.
That is a fact.
You seem to be talking about existing specimens here. And how do you explain these specimens origins? If it can explain what you wrote then it should be able to explain how they showed up from non-living matter with no creator..
angel wrote:BTW you did not anwered my question. Are we still discussing if dolphins share a common ancestor with ground mammals?
I'm not asking about the evolution being run by random mutations and selection. I'm just asking if you agree that they share a common ancestor.
No, I don't agree that they share a common ancestor. As I've stated before I believe they share a common creator...

Posted: Mon Nov 20, 2006 2:39 am
by The edge
I've never seen a land mammals with blow holes on their back. Can't imagine evolution can make such a huge shift.

Posted: Tue Nov 21, 2006 7:44 am
by angel
answersingenesis.org is not what I meant by serious scientific discussion. My bad of course.
And how do you explain these specimens origins?
The origin of life is completely disconnected from the problem of common ancestors and evolution.
Scientific knowledge about origins of life is quite approximate and yet not based on solid ground.
No, I don't agree that they share a common ancestor. As I've stated before I believe they share a common creator...
The two things are not mutually exclusive. I could believe in a designer which acts by producing the "right" mutations to guide evolution along a designed path, couldn't I?
I believe some if not most of the IDs tend to think in these terms.

How do you explain viral insertions?

How do you imagine your creator does in fact "create" a new specimen? Two individuals pop out of vacuum, they are modelled with dust and then brought to life, or what else?




The edge
I've never seen a land mammals with blow holes on their back. Can't imagine evolution can make such a huge shift.
Well, I guess in most cases back and front is quite unprecise. Our nose is certainly on our front.
Most dogs, cows, seals etc have their nose just in between upside and bottomside.

Do you believe dolphins have been created as they are or that they evolved from fishes?

Posted: Tue Nov 21, 2006 7:12 pm
by Gman
angel wrote:answersingenesis.org is not what I meant by serious scientific discussion. My bad of course.
If you would like similar analogies on evolution from non-creationist sources I could provide you with some. Actually, I'm not a direct supporter of AIG but sometimes I will use them if I think they support a case. To dismiss them as being totally unscientific is not fair though in my book...
The origin of life is completely disconnected from the problem of common ancestors and evolution.
Scientific knowledge about origins of life is quite approximate and yet not based on solid ground.
I would assume that if we all evolved from a common ancestor we would have some common similarities with other species. In some cases we do, in other cases we don't. If we did have a clear common ancestor, then why are we debating this? It should be obvious from the fossil records...
The two things are not mutually exclusive. I could believe in a designer which acts by producing the "right" mutations to guide evolution along a designed path, couldn't I?

I believe some if not most of the IDs tend to think in these terms.
Angel, actually you could. I'm not against such beliefs as long as they fit the scientific model. Also, in the case of ID, I believe it should be left to the individual on who they believe the designer is... God, Allah, Buddha, Aliens, etc... Who cares..
How do you explain viral insertions?

How do you imagine your creator does in fact "create" a new specimen? Two individuals pop out of vacuum, they are modelled with dust and then brought to life, or what else?
I don't know exactly how he did it.. Again, I'm not against science and evolution or the study of it. Only when it gets to origins. To me, it should be left open to debate in the public system. Even though I'm a creationist, I do NOT want creationism taught in our public schools and will vote it down if given the chance.. Let's just say both are in the works and report that we don't have all the facts in yet (like you said)... Tell it like it is... I don't understand why this is such a big problem..

Posted: Wed Nov 22, 2006 8:07 am
by hetfield
this reminds me of a simpsons episode i saw back in 2000. it dealt with dolphins coming back to earth and kicking man off claiming that they were here first. but anyway what inspired this to happen? it's interesting, but anyway if it isn't happening worldwide or in all the dolphin species then it's just a random genetic mutation.

Posted: Wed Nov 22, 2006 8:19 am
by angel
GMan
If you would like similar analogies on evolution from non-creationist sources I could provide you with some.
Yes, please. I would appreciate it.
GMan
Actually, I'm not a direct supporter of AIG but sometimes I will use them if I think they support a case. To dismiss them as being totally unscientific is not fair though in my book...
I did not say they are totally unscientific.
However, as when discussing about ID I like to let IDs define what ID is, now I prefer to keep stuck to what biologists say about biology. It usually helps in preventing strawmen.

They may be correct and totally scientific. If so they are reporting faithfully the claims of biologists. In that case I prefer to discuss biologists' claims directly.

GMan
I would assume that if we all evolved from a common ancestor we would have some common similarities with other species. In some cases we do, in other cases we don't.
We share a lot with escherichia coli!
Most of the basic biochemical structures and mechanisms, for instance.
Please, be explicit.
Are you claiming that you can produce evidences of totally different organismswith no similarities?
This (for example organisms based on right handsided amminoacids) would be enough evidence to disprove the common ancestro theory (though maybe not to disprove a common ancestor between humans and chimps).
Please if you have such data, I would be more than happy to consider it.

GMan
If we did have a clear common ancestor, then why are we debating this?
It should be obvious from the fossil records...
We are discussing because we strongly disagree on what "clear" means.
Fossil records are not the unique nor the most direct argument in favor of common ancestor scenario. The clearest argument today are coming from genetics of living lifeforms.
And they are becoming stronger and stronger.
For example we can directly compute on a purely genetic basis how long ago we shared our common ancestors with chimps (gorilla, ...).
The genetic dating is pretty good agreeing with the known fossil record dating. The record may be lacking and incomplete but there is no way in which you can show this agreement to be necessary if the designer created humans and chimps independently.
I'm not saying that you cannot force your creationist scenario with it (goddidit argument is perfect) I'm just saying that you have to assume that your designer decided to do so for some unknown reason, while the "coincidence" is perfectly predicted by evolution.
GMan
Angel, actually you could. I'm not against such beliefs as long as they fit the scientific model. Also, in the case of ID, I believe it should be left to the individual on who they believe the designer is... God, Allah, Buddha, Aliens, etc... Who cares..
Well. the point is exactly this. In science the final judge is not the individual but the experiment/observation.
It is something it should be decided by observing nature and evaluating arguments.
Science is not a democracy in which you are free to think that the Earth stands still and the sun goes around.
Of course you are free to believe what you please (as a friend of mine likes to say) but when you do it you are not doing science anymore.
Here we are discussing about science (and faith), I supposed.
In any event, that was what I meant by "some *scientific* argument".
GMan
I don't know exactly how he did it.. Again, I'm not against science and evolution or the study of it. Only when it gets to origins.
Do you mean the origins of species or the origin of life all together?

And in any case, what do you mean by you are against science in that case?
Science is simply enumerating and weighting evidences.

One cannot be against mathematics when one gets to the multiplications by 7!
One is free not to use mathematics, but I cannot understand how one can be "against" mathematics.

As I said, I don't think that one necessarily needs to believe or to care about what science claims. But likes or dislikes are not among the arguments which should be used to judge science scientifically.
GMan
To me, it should be left open to debate in the public system.
There is no debate in the scientific community about common ancestor.
And the public debate is irrelevant to science.

I hope we agree that science is a self contained discipline with its own laws and procedures
which are and have to be disconnected by social issues.

GMan
Even though I'm a creationist, I do NOT want creationism taught in our public schools and will vote it down if given the chance.. Let's just say both are in the works and report that we don't have all the facts in yet (like you said)... Tell it like it is... I don't understand why this is such a big problem..
The problem is simply that despite what you think, there is no scientifc doubt about the fact that we share a common ancestor with chimps.
And there won't be any doubt in the future.

Moreover, to use your own words, we have not in yet nothing. We have no final answer about gravity, about cosmology, about quantum mechanics, etc.
We do not even know if we will ever have a final answer.

Are you suggesting that we should suspend teaching these as well?

Posted: Wed Nov 22, 2006 8:29 am
by angel
Hi hetfield!

In fact I chose the title of this thread by thinking to The Hitchhiker's Guide to the Galaxy by D. Adams. More precisely to its fourth part (So long and thanks for all the fish). Very funny.

I missed that simpson. The idea is quite similar, though.

Posted: Wed Nov 22, 2006 10:13 pm
by hetfield
angel wrote:Hi hetfield!

In fact I chose the title of this thread by thinking to The Hitchhiker's Guide to the Galaxy by D. Adams. More precisely to its fourth part (So long and thanks for all the fish). Very funny.

I missed that simpson. The idea is quite similar, though.
i guess you get the hetfield reference also. james hetfield. metallica, really good band, but anyway is this the first of it's kind or has their been any other dolphins like this found?

Posted: Fri Nov 24, 2006 3:58 am
by angel
It seems it is the first of this kind found and reported.

PS: I like 'em as well. I got a piece by them playing star wars soundtrack which is fantastic.
It reminds me when I was young, before the clones' war. :P :)