Take The Tiktaalik Challenge

[Oncedeceived]

The tetrapods before Tiktaalik were also fishapods. The tetrapods after Tiktaalik were also fishapods. There are at least 14 named genera. Was is it not transitional?

I think that you are incorrect here. Tiktaalik was discovered and then later the fossilized footprints of true Tetrapods were discovered. There were true tetrapods not just fishapods before Tiktaalik.

 

[Loudmouth]

That really isn't the issue. You said that there were no tetrapods before Tiktaalik.

And now I have corrected myself. Tiktaalik was found in a geologic era very close to the emergence of the first tetrapods.

I'm curious why it is considered a transitional between placental mammals and reptiles when in fact the eggs it lays are closer in structure to birds.

They aren't closer in structure to birds. They are leathery, just like reptiles.

It bill is closer to a duck (I know I know it is not like a duck bill other than appearance)

No, it isn't. You are absolutely wrong on this one. The lower jaw of a bird has 3 bones. The lower jaw of a mammal has a single lower jaw bone. The platypus has a single lower jaw bone. Beyond that, the two bills couldn't be more different. Check it out for yourself.

duck:
http://www.hiltonpond.org/images/SkullDuckWoodTop01.jpg

platypus:
http://www.cabrillo.edu/~jcarothers...ALS/specimens/images/platypus skull 2_JPG.jpg

it has a tail like a beaver so is it a representative of reptile to rodent, reptile to bird, reptile to mammal?

It is an example of you trying to create confusion where none exists which appears to be your MO of late.

I didn't say that.

Yes, you did.

I thought that for a missing link to be a true missing link it had to be a an ancestor to the following fossil form.

That is a creationist misconception. There is no way to determine if any fossil has a living descendent. What we can do is determine what mixtures of characteristics a fossil has and how it compares to other species. That is how we determine if it is transitional or not.

 

[Loudmouth]

I think that you are incorrect here. Tiktaalik was discovered and then later the fossilized footprints of true Tetrapods were discovered. There were true tetrapods not just fishapods before Tiktaalik.

Why don't you show us these tetrapods. Links to pictures would be helpful.

From what I recall, all they have found are footprints which does nothing to help us determine if it is an early tetrapod with a lot of fish features.

 

[lasthero]

it has a tail like a beaver so is it a representative of reptile to rodent, reptile to bird, reptile to mammal?

It's tail is actually not like a beaver. They look similar at a distance, but upon closer inspection, they're quite different. Beaver tails are flatter, smaller, and they have these scales on them, and the beaver uses it for propulsion. The platypus uses it to in steering and that's it. As with a lot of things involving the playtpus, it kind of looks like something, but upon closer inspection...

And rodents ARE mammals, so 'reptile to rodent' and 'reptile to mammal' wouldn't even contradict each other.

 

[Oncedeceived]

Why don't you show us these tetrapods. Links to pictures would be helpful.

From what I recall, all they have found are footprints which does nothing to help us determine if it is an early tetrapod with a lot of fish features.

Their was some controversy but since then I do believe their is a consensus on this being actual tetrapods.


The creatures left the footprints as they tramped through mud in what was at the time an intertidal marine lagoon, south of the equator, along the south coast of the supercontinent called Laurasia.
Why might tetrapods have evolved to crawl onto land from the sea rather than from rivers or lakes? One hypothesis put forward by Niedźwiedzki is that the seashore provided a tempting new source of food: stranded fish, served up twice daily by the tides.
However, Ted Daeschler of the Academy of Natural Sciences in Philadelphia, Pennsylvania, warns that fossilised footprints can be misleading. "With all due respect to the scientists involved in this study, there may be other explanations for these suggestive tracks and traces," he says.
Clack, however, believes a reassessment of the consensus view on tetrapod evolution might be in order. "The evidence that these footprints were made by bona fide tetrapods is convincing," she says.


http://www.newscientist.com/article/dn18346-oldest-footprints-of-a-fourlegged-vertebrate-discovered.html#.UoueIOKBLZI

Here is a link for a blog that has a video too.

http://evolutionbioc334.blogspot.com/2012/03/walking-with-tetrapods.html

 

[HitchSlap]

Their was some controversy but since then I do believe their is a consensus on this being actual tetrapods.


The creatures left the footprints as they tramped through mud in what was at the time an intertidal marine lagoon, south of the equator, along the south coast of the supercontinent called Laurasia.
Why might tetrapods have evolved to crawl onto land from the sea rather than from rivers or lakes? One hypothesis put forward by Niedźwiedzki is that the seashore provided a tempting new source of food: stranded fish, served up twice daily by the tides.
However, Ted Daeschler of the Academy of Natural Sciences in Philadelphia, Pennsylvania, warns that fossilised footprints can be misleading. "With all due respect to the scientists involved in this study, there may be other explanations for these suggestive tracks and traces," he says.
Clack, however, believes a reassessment of the consensus view on tetrapod evolution might be in order. "The evidence that these footprints were made by bona fide tetrapods is convincing," she says.


http://www.newscientist.com/article/dn18346-oldest-footprints-of-a-fourlegged-vertebrate-discovered.html#.UoueIOKBLZI

Here is a link for a blog that has a video too.

The Facts and Theories of Evolution: "Walking with Tetrapods"

Do you have a picture of the fossilized tetrapod referenced in your link?

 

[Oncedeceived]

It's tail is actually not like a beaver. They look similar at a distance, but upon closer inspection, they're quite different. Beaver tails are flatter, smaller, and they have these scales on them, and the beaver uses it for propulsion. The platypus uses it to in steering and that's it. As with a lot of things involving the playtpus, it kind of looks like something, but upon closer inspection...

And rodents ARE mammals, so 'reptile to rodent' and 'reptile to mammal' wouldn't even contradict each other.

I said tail like a beaver, which I might add is how it is sometimes described in some literature. I also didn't say it contradicted anything either.

 

[lasthero]

I said tail like a beaver, which I might add is how it is sometimes described in some literature.

But it's tail isn't really 'like' a beaver, no more than, say, a whale's fin is 'like' a fish's fin. They have some similarities, but when you observe them closely you realize how different they are.

 

[Oncedeceived]

Do you have a picture of the fossilized tetrapod referenced in your link?

No I'm sorry I don't.

 

[HitchSlap]

No I'm sorry I don't.

Don't you think that you're making some strong assertions without having all the evidence yet?

 

[Herman Hedning]

Perhaps then you would care to explain to us the role the Innuits played in Tiktaalik getting its name?

Quoting from page 24 of Your Inner Fish:

As the discoverers of the creature, Ted, Farish and I had the privilege of giving it a formal scientific name. We wanted the name to reflect the fish's provenance in the Nunavut Territory of the Arctic and the debt we owed to the Inuit people for permission to work there. We engaged the Nunavut Council of Elders, formally known as the Inuit Qaujimajatuqangit Katimajit, to come up with a name in the Inuktitut language. My obvious concern was that a committee named Inuit Qaujimajatuqangit Katimajit might not propose an scientific name we could pronounce. I sent them a picture of the fossil, and the elders came up with two suggestions, Siksagiaq and Tiktaalik. We went with Tiktaalik for its relative ease of pronunciation for the non-Inuktitut-speaking tongue and because of its meaning in Inuktitut: "large freshwater fish."​

All clear now?

 

[Oncedeceived]

But it's tail isn't really 'like' a beaver, no more than, say, a whale's fin is 'like' a fish's fin. They have some similarities, but when you observe them closely you realize how different they are.

That is just fine. I have no issue with that.

 

[Loudmouth]

Their was some controversy but since then I do believe their is a consensus on this being actual tetrapods.


The creatures left the footprints as they tramped through mud in what was at the time an intertidal marine lagoon, south of the equator, along the south coast of the supercontinent called Laurasia.
Why might tetrapods have evolved to crawl onto land from the sea rather than from rivers or lakes? One hypothesis put forward by Niedźwiedzki is that the seashore provided a tempting new source of food: stranded fish, served up twice daily by the tides.
However, Ted Daeschler of the Academy of Natural Sciences in Philadelphia, Pennsylvania, warns that fossilised footprints can be misleading. "With all due respect to the scientists involved in this study, there may be other explanations for these suggestive tracks and traces," he says.
Clack, however, believes a reassessment of the consensus view on tetrapod evolution might be in order. "The evidence that these footprints were made by bona fide tetrapods is convincing," she says.


http://www.newscientist.com/article/dn18346-oldest-footprints-of-a-fourlegged-vertebrate-discovered.html#.UoueIOKBLZI

Here is a link for a blog that has a video too.

The Facts and Theories of Evolution: "Walking with Tetrapods"

Still, we are talking about 10 million years, a geologic eye-blink. All they have are footprints. We still don't have information on whether or not the species that left these tracks had internal gills or other fishapod features. Also, this does not put Tiktaalik's transitional features in doubt. What we have is a platypus of sorts. We have less derived features that stuck around in one of the sister taxa.

 

[HitchSlap]

Still, we are talking about 10 million years, a geologic eye-blink. All they have are footprints. We still don't have information on whether or not the species that left these tracks had internal gills or other fishapod features. Also, this does not put Tiktaalik's transitional features in doubt. What we have is a platypus of sorts. We have less derived features that stuck around in one of the sister taxa.

And still well within the Devonian era, no?

 

[Loudmouth]

And still well within the Devonian era, no?

Exactly. It is still very possible that Tiktaalik changed very little over a span of 20 million years, and that these earlier Tiktaalik ancestors were actually ancestral to tetrapods. More fossils will need to be found. What we have now are more than enough to demonstrate tetrapod evolution from aquatic ancestors. All that is left is filling in the fine details.

 

[Oncedeceived]

Still, we are talking about 10 million years, a geologic eye-blink. All they have are footprints. We still don't have information on whether or not the species that left these tracks had internal gills or other fishapod features. Also, this does not put Tiktaalik's transitional features in doubt. What we have is a platypus of sorts. We have less derived features that stuck around in one of the sister taxa.

Why do you suppose Jenny Clack is so adamant about them being a bona fide
tetrapod? Do you think she is not equipped to make that determination?

 

[Oncedeceived]

And still well within the Devonian era, no?

So I ask you too, why do you think that Jenny Clack is so adamant about it being bona fide Tetrapods?

 

[Loudmouth]

So I ask you too, why do you think that Jenny Clack is so adamant about it being bona fide Tetrapods?

Why would it be a problem if they were bona fide tetrapods?

 

[HitchSlap]

Why do you suppose Jenny Clack is so adamant about them being a bona fide
tetrapod? Do you think she is not equipped to make that determination?

I don't know. Why do you think?

 

[Oncedeceived]

I don't know. Why do you think?

I think she has determined this by the fact that it shows the creature to have the abilities and characteristics that would provide evidence that the tracks were made by what she said they were made by. It seems that is the consensus now due to the fact that when you look up anything about it, it seems that there are considered to be actual tetrapod tracks.