Dolphin reveals an extra set of ‘legs’

[gallo]

Quote by: kubedawg ZOMG THAT'S AN AWESOME THEORY!

Not sure what theory you are talking about. You aren't very responsive or specific in your posts.

But, what I meant was not the embyonic [sic] development of a human, but the evolution from bacteria, to dolphin, to human.

There was no evolution from bacteria to dolphin to human. And if you weren't talking about human embryonic development, why did you say "early stages of human life"? What is that supposed to mean. Let me say it again for you. Anything that could be remotely considered human never has scales, fins, nor gills. You seem to be having trouble grasping the meaning of "never".

How is it that you consider bacteria and dolphins to be human?

[kubedawg]

Quote by: gallo There was no evolution from bacteria to dolphin to human.

How do you know? Prove it.

[Jack]

How do you know? Prove it.

That's just being silly, not debating. Are you saying that you might be willing to entertain the possibility that we descended from dolphins, and they from bacteria? Then you're admitting that you don't understand the most basic concepts of the science that underlies evolution.

[kubedawg]

Possibility, yes. Probability, no. Negative over a positive, quite possibly.

[gallo]

Quote by: kubedawg Possibility, yes. Probability, no. Negative over a positive, quite possibly.

Mindless. No. It isn't possible. You are only demonstrating your profound ignorance of the topic.

[Ricardo.H]

Perhaps these dolphins have started to devolve or so. Or perhaps a mutation caused by pollution in the ocean? Either way these dolphins with that unique trait will survive or die off. It's the law of nature. Apart from this, I don't see dolphins part of the human evolution chain. I would understand life coming out of the sea but not of these organism. Their ancestors choose to stay in the sea and thus evolved to suit their environment.

[lisadilaw]

I think that he reason the dolphin has an extra set of legs is not because of evolution but pollution. All over the world companies dump toxic waste into the ocean. Sooner or later all of these chemicals would have had a negative effect on dolphins. Babies would be born deformed. some species would even become extinct

[gallo]

Quote by: Ricardo.H Perhaps these dolphins have started to devolve or so.

As far as biology is concerned, there is no such thing as "devolution." The concept is based on a rejected philosophy of biology called finalism. It is the idea that the living world has a propensity to move toward greater perfection. The view has been held as far back as Aristotle. But Darwin rejected such obscure, unobservable forces. The word "evolution" in Darwin's day actually meant change in a particular direction, along a particular path, from primitive to advanced, from simple to complex, and from imperfect to perfect. That's why Darwin didn't like and didn't use the word. Although you still hear the concepts of finalism expressed, the philosophy has been rejected by modern evolutionary biology. The old connotation of the word evolution is still used in science, for example, when talking about the evolution of a star, which develops along a fixed path. However, in evolutionary biology, the word is more limited and specific. It means change in the genetic makeup of a population over generations. Thus, if this particular throw back is, in fact, caused by genetic change, then it is just evolution.

Quote by: Ricardo.H Or perhaps a mutation caused by pollution in the ocean?

Doubtful. Dolphins have hind limbs during some phases of gestation. This isn't as rare as you might believe. During the days of whaling, whales were found from time to time with rear limbs. As mentioned, some species have the remnants of the pelvis and legs inside their bodies.

Quote by: Ricardo.H Either way these dolphins with that unique trait will survive or die off. It's the law of nature.

These aren't "dolphins". It is a single dolphin. And that's quite a law that you've invented. Evolutionarily speaking, it is a characteristic in a population that survives or disappears, depending on whether it provides a reproductive advantage or not. Extinction is another question.

Quote by: Ricardo.H Apart from this, I don't see dolphins part of the human evolution chain. I would understand life coming out of the sea but not of these organism. Their ancestors choose to stay in the sea and thus evolved to suit their environment.

While whales and dolphins are descended from a kind of even toed ungulate while humans are primates. Dolphins are not in our lineage. However, the ancestors of dolphins did not "choose" to stay in the sea. They are descended from land animals that adapted to the sea. There are many animals that are currently adapting to an aquatic life from the land, for example, the Odobenidae (walruses), Otariidae (sea lions), and Phocidae (seals), three families of the order Carnivora.

[gallo]

Quote by: lisadilaw I think that he reason the dolphin has an extra set of legs is not because of evolution but pollution. All over the world companies dump toxic waste into the ocean. Sooner or later all of these chemicals would have had a negative effect on dolphins.

While it might be possible, in the case of a single example I don't think that it is the case. Besides, as mentioned, this sort of thing isn't unheard of among the Cetacea. It is more likely a developmental error in which the rear limbs failed to be reabsorbed in the foetus.

Quote by: lisadilaw Babies would be born deformed. some species would even become extinct

True. We have seen that happen.

[Flea_Bit_Monkey]

Quote by: Isherwood Cute idea. It actually makes as much sense as the idea that dolphins and elephants were created just as they are today by an invisable superman about 6000 years ago.

Or that complex lifeforms sprang from soup by accident.

[gallo]

Quote by: Flea_Bit_Monkey Or that complex lifeforms sprang from soup by accident.

That is certainly true. But only creationists who cannot support their magic creation mythology with logic need to make up such straw men.

[Compugasm]

Quote by: gallo Maybe they should be referred to as the pharyngeal pouches.

You got a better name for the cereal "Grape Nuts"?

[gallo]

Quote by: Compugasm You got a better name for the cereal "Grape Nuts"?

You have a point since like gill slits, which are neither gills nor slits, Grape Nuts are neither grapes nor nuts. However, "wheat and malted barley baked until rock hard," while descriptive, doesn't seem like it would be commercial. On the other hand, pharyngeal pouches is descriptive and would possibly eliminate the confusion of the ignorant. It does have the disadvantage of being harder to spell.

If fact, we did call them pharyngeal pouches in my embryology class because the professor didn't like the term gill slits because they are neither...well...you know.

[Hostile55]

If fact, we did call them pharyngeal pouches in my embryology class because the professor didn't like the term gill slits because they are neither...well...you know.

Not quite true. They do go on to form gills in some animals so 'gill slits' is descriptive. They are the precursors to gills. Whether they are slits or not is a matter of semantics. Just like the dolphin never actually grows legs.

The point is, that we have something that we don't need growing on us when we are in the womb, that could, if a gene or two was turnd on or off, grow into gills. IE we evolved from fish, as per the old theory.

[Fonceai]

Quote by: Hostile They do go on to form gills in some animals so 'gill slits' is descriptive.

I hate to be a dick, but you beg the following question:

What kind of animal, growing from an embryo, goes on to have gills?

[gallo]

Quote by: Hostile55 Not quite true.

The concept isn't that difficult. Or at least I didn't think it was. Gill slits are neither gills nor slits.

Quote by: Hostile55 They do go on to form gills in some animals so 'gill slits' is descriptive.

They also go on to form parts of the ears and jaw in some animals so I guess we should call them ears or jaws by your logic.

Quote by: Hostile55 They are the precursors to gills.

They are also the precursors to ears.

Quote by: Hostile55 Whether they are slits or not is a matter of semantics.

Only if you ascribe to the debunked evolutionary philosophy that ontogeny recapitulates phylogeny. They aren't slits in any tetrapod, just as they are not gills.

Quote by: Hostile55 Just like the dolphin never actually grows legs.

Semantics. Those structures do go on to become legs in other animals.

Quote by: Hostile55 The point is, that we have something that we don't need growing on us when we are in the womb, that could, if a gene or two was turnd on or off, grow into gills.

Actually, that's not the point since the "gill slits" are not structures "growing on us" when we are in the womb that we don't need. Those structures "go on" to form certain structures of the neck, jaw, and head in tetrapods.

Quote by: Hostile55 IE we evolved from fish, as per the old theory.

What theory is that?

[gallo]

Quote by: Fonceai What kind of animal, growing from an embryo, goes on to have gills?

A fish.

[Fonceai]

Sorry, I should rephrase the question.

What kind of animal, growing in a womb, goes on to have gills?

I thought the very definition of animals that grow in a womb was that they aren't fish.

[gallo]

Quote by: Fonceai Sorry, I should rephrase the question. What kind of animal, growing in a womb, goes on to have gills?

None.

Quote by: Fonceai I thought the very definition of animals that grow in a womb was that they aren't fish.

Maybe, but that isn't the definition of embryo.

[Fonceai]

I know. I realized my error.

But we're talking about mammals.

No mammal develops gills.

That's why the comment seemed rather strange, to me.