Tiktaalik is still being used as a successful prediction of something. I know it was supposed to be a successful prediction of universal common descent because it is A) Allegedly a transitional form between fish and tetrapods and B) It was found in the “correct” strata because allegedly no evidence of tetrapods before 385 million years ago- plenty of fish though and plenty of evidence for tetrapods around 365 million years ago- Tiktaalik was allegedly found in strata about 375 million years old- Shubin said that is the strata he looked in because of the 365-385 range already bracketed by existing data.
The thinking was tetrapods existed 365 mya and fish existed 385 mya, so the transition happened sometime in that 20 million years.
Sounds very reasonable. And when they looked they found Tiktaalik and all was good.
Then along comes another find that put the earliest tetrapods back to over 390 million years ago.
Now had this find preceded Tiktaalik then Shubin et al. would not have been looking for the transitional after the transition had occurred- that doesn’t make any sense. And that is why it is a failed prediction- the transition occurred some 25 million years before, Shubin et al., were looking in the wrong strata.
That said Tiktaalik is still an interesting find, something that no on else had ever found and it adds to our knowledge base of organisms that once existed. But that is all it does.
Let’s return to our problem of how to find relatives of the first fish to walk on land. In our grouping scheme, these creatures are somewhere between the “Everythungs” and the “Everythings with limbs”. Map this to what we know of the rocks, and there is strong geological evidence that the period from 380 million to 365 million years ago is the critical time. The younger rocks in that range, those about 360 million years old, include diverse kinds of fossilized animals that we would recognize as amphibians or reptiles. My colleague Jenny Clark at Cambridge University and others have uncovered amphibians from rocks in Greenland that are about 365 million years old. With their necks, their ears, and their four legs, they do not look like fish. But in rocks that are about 385 million years old, we find whole fish that look like, well, fish. They have fins. conical heads, and scales; and they have no necks. Given this, it is probably no great surprise that we should focus on rocks about 375 million years old to find evidence of the transition between fish and land-living animals.- Neil Subin pages 9-10
Just as I have been saying- go figure. Got that- he was looking for evidence of THE transition- he was not looking for any ole transitional form. And there isn’t any reason why a transitional form would be around millions of years after the transition occurred.
But anyway, the point is had the new data been available to Shubin- the data that puts the transition back to before 390 million years ago- that whole set up would be meaningless and wrong. Meaning he would not have been looking where he did.
Rich- TRY to think of the consequences here-
If I am right all it means is he was looking in the wrong strata
If you are right it means his entire first chapter is nothing but a big, useless distraction. And the part I quote is nothing but a deception.
But anyway I posted a challenge and it is very telling that you haven’t taken it.
Here is the challenge (again) read the following passgae from “Your Inner Fish” and my paraphrasing of what it says. If you agree with me please say so and if you disagree then please make your case:
OK man-up, if you dare- In my words- they represent the time when there were fish, and no tetrapods-> 385 mya and a time when there were fish and tetrapods-> 365 mya.
Is there anyone who thinks differently? Please make your case.
Yes, Joe, TRY and think of the consequences. If you find the RIGHT thing, how can it be the WRONG strata?
It all boils down to your misunderstanding here:
Was it the right thing? It was found in the wrong strata.
The right thing, the thing Shubin said he was looking for, occurred millions of years before.
Joe, populations often survive largely unchanged, for millions of years. Shubin figured, correctly, that a population of transitional tetrapods were likely to have lived in a littoral habitat now stratified in rock near the surface at Nunavut.
And his prediction was supported.
A transition isn’t an event. It’s a population of organisms with features between an ancestral population and one of that ancestral population’s descendent population.
Any population alive today could be considered a “transitional” population by future palaentologists.
Elizabeth- did you read the book? He said he was looking for evidence for the event- I quoted him.
You should ask yourself why all his other expeditions came up empty because they werer based on the same vague “criteria” you laid out in your opening sentence.
Your words aren’t his thoughts. He clearly talks about fossils, not “the time when there were fish, and no tetrapods”. So, you are wrong.
There is no challenge. Your errors have already been pointed out and corrected. Repeating them wont make them true, but it is a common creationist trope.
According to Shubin that is what the fossils say- that was his whole point in the quote I provided and the first chapter of his book.
What errors? Please be specific.
That is why I issued teh challenge to give you an opportunity to support your claim.
Rich- TRY to think of the consequences here-
If I am right all it means is he was looking in the wrong strata
If you are right it means his entire first chapter is nothing but a big, useless distraction. And the part I quote is nothing but a deception.
You claim Schubin says things he doesn’t. See here:
TRY to think of the consequences here –
He found what he was looking for, so it was the RIGHT place, by definition.
I made my case. Strange that you can’t make yours.
So Rich refuses to deal with it-
Rich- TRY to think of the consequences here-
If I am right all it means is he was looking in the wrong strata
If you are right it means his entire first chapter is nothing but a big, useless distraction. And the part I quote is nothing but a deception.
And another prediction fulfilled- Lizzie stepping in will be another prediction fulfilled.
Not according to what he wrote in the book.
It it was found to be wrong:
Yes, your understanding of what Schubin, said, as evidenced here:
It is right there in the quote I provided. And no one has been able to provide any reasoning as any other possible inference.
So what? He called you to deliver a pizza- or was it chinese?
If I am right all it means is he was looking in the wrong strata
If you are right it means his entire first chapter is nothing but a big, useless distraction. And the part I quote is nothing but a deception.
Ooh, look.
http://www.bloomberg.com/news/2012-03-05/scottish-fossil-trove-shows-when-sea-creatures-started-walking-on-land.html
Interesting stuff, even if I can only see the PNAS abstract
ETA – Hat Tip to SteveF at TalkRational
Darn. In case the edit doesn’t get through, hat tip to SteveF at TalkRational for the above
So evidently I’m more qualified to talk about his thoughts than you are.
If you are right it means his entire first chapter is nothing but a big, useless distraction. And the part I quote is nothing but a deception.
Or, much more likely, it means you didn’t understand it, or purposefully misinterpreted it. Like you do.
Well Rich I have given you plenty of opportunity to make your case but you refuse. So until you actually ante up I will go with what he wrote in the book.
Oh, that book you don’t understand, as evidenced here:
Sorry.
The one you have never read, yes that one.
Still no ante and only yourself as support for your claims?
LoL!
I have the book and see nothing wrong with the first chapter or with the passage quoted. Nor does anyone else. No one who has followed the discussion of Tiktaalik would have any reason to conclude that tetrapods popped up or disappeared instantaneously.
With luck, more will be found, representing a wider range of features.
Cut it out- read the OP
Sorry, read it. Thoroughly enjoyed it. Have you finished being wrong yet?
Joe, I’ve read the book as well, and I don’t see anything that implies that Shubin thought that the “transition” was a short-lived “event”.
It’s not what “transition” means in palaeontology.
Elizabeth- I never said nor implied it was short-lived transition and my argument doesn’t require a short-lived transition.
He bracketed two time periods and said to look for evidence of the transition between those two time periods. Had he known about the find in Poland he would have shifted his brackets accordingly in order to fit his argument, which I quoted.
OK then tell us why he said what I quoted- what is this all-elusive “real” meaning behind his words?
Learn me sumthin
So if this:
Doesn’t = In my words- they represent the time when there were fish, and no tetrapods-> 385 mya and a time when there were fish and tetrapods-> 365 mya.
Then please tell me what is really means. Thank you.
Has it occurred to you that specimens from this era are rather scarce? In fact, so scarce that Tik is the first of its kind to be found. So given that the record is monumentally incomplete, what is so surprising about finding something that is a few percent older or younger than expected?
Well, of course Tiktaalik is the expected age. What was unexpected was the discovery of what are, apparently, tetrapod tracks in strata rather older than the expected time of the earliest tetrapods.
Which is sort of cool. It doesn’t make Shubin’s prediction wrong (how could it? He predicted transitional tetrapods and he found them exactly where he’d predicted them!) but it does make the date of the earliest tetrapods move a bit further backwards in time.
I’m looking forward to Per Ahlberg’s promised paper.
Joe:
And there isn’t any reason why a transitional form would be around millions of years after the transition occurred.
Sure there is; every population of a species has its own evolutionary trajectory, independent of the others. Tiktaalik may have consisted of numerous populations, each evolving along different lines. Even if one of those lines really was transitional to amphibians, many others may have remained relatively morphologically stable. Thus, you could easily find a transitional fossil type millions of years after the transition. In fact, finding a representative fossil of the actual transitional population would be pretty remarkable (and hard to prove).
Elizabeth,
Does what Shubin said mean what I said it means? First things first, please- pretty please- with Bailey’s and Disaranno’s on top
Strange how all of the alleged transitionals leading to us have went extinct in just a few million years.
So what is the time limit? Anything or everything? You know what “everything” does to any predictions- and why didn’t he find any trandsitionals in other strata? Why hasn’t anyone found such a transitional in other strata?
Why aren’t they all over the place then?
We still have lungfish, mud puppies, cockroaches alligators, horseshoe crabs. What survives survives.
Well, it’s a while since I read it, Joe, but I do think you’ve got it a bit wrong. The idea of Common Descent is that the Tree of Life is full of twigs and branches, and most of the twigs end well before the present. A “transitional” organism is simply one sitting on a twig from a node between two other nodes. I mean obviously it would be awesome to find a fossil from an actual directly ancestral population, but given that the vast majority of lineages never reached the present, and that fossilisation is rare, that’s pretty improbable.
So I really don’t think there was much wrong with Shubin’s prediction. In fact, it was spectacularly successful! But it those tracks are certainly intriguing, and no doubt the picture of tetrapod evolution is going to look a bit different in a few years time. BTW there is new edition of Jenny Clack’s book Gaining Ground coming out next month.
I think popular science writing often speaks of ancestors when they mean a distant cousin of an ancestor. This causes a lot of unnecessary arguing over things that don’t need to be argued about.
It should seem obvious that if the sum total of fossils covering a 40 million year period consists of a couple of fragments and a few footprints, there’s a lot of history we don’t know.