Blinn

Go to <a href="http://www.pbs.org" target="_blank">www.pbs.org</a> and then locate your local station. There should be a programming schedule there.

Kosh

Did that, but I'm gonna have to click through
EVERY day to look for it. No search function!
&lt;whine&gt;

Per Ahlberg

I have been lurking here for a while, but this seemed like a good time to pop my head above the parapet. Glad to hear the programme went down well; I haven't seen it yet, though WGBH are supposed to be sending me a tape. I don't know about the relationship between 'NOVA' and 'Horizon' in general, but this particular programme started life as an episode of 'Horizon' (broadcast 1 February 2001). However, WGBH re-edited the programme quite thoroughly, and it sounds like they improved it.

If anybody wants more information about Livoniana (the intermediate fish/tetrapod jaw), the reference for the formal description is:

Ahlberg, P.E., Luksevics, E. & Mark-Kurik, E. 2000: A near-tetrapod from the Baltic Middle Devonian. Palaeontology 43, 533-548.

Unfortunately it is not available online, but I think most university geology libraries take 'Palaeontology'.

Incidentally, Jenny Clack and I are now working on a redescription of Ichthyostega, together with a postdoc called Henning Blom. There are quite a few problems with Jarvik's interpretation, particularly as regards the structure of the skull and middle ear, so the story of the origin of tetrapods is likely to acquire some interesting new twists over the next few years...


Cheers, Per

Oolon Colluphid

Blimey! And indeed Wow! <img src="graemlins/notworthy.gif" border="0" alt="[Not Worthy]" /> <img src="graemlins/notworthy.gif" border="0" alt="[Not Worthy]" />

Welcome to the boards as a poster, Per. Please stop by more often!

Thanks for letting us know about the redescription. You do realise that whatever you say, it's still a fish though... or still an amphibian... er...

Seeing Jenny Clack's name rang a bell... turns out she did <a href="http://tolweb.org/tree/eukaryotes/animals/chordata/ichthyostega/ichthyostega.html" target="_blank">this page</a> about Ichthyostega at the Tree of Life site. Meant to have posted it here before now.

<a href="http://www.mdgekko.com/devonian/Order/old-order.html" target="_blank">New Findings Upset Old Order</a> is interesting too.

And the chances of the revamped version making it onto British telly are tiny, I'd guess .

Best wishes, Simon

Kosh

Ditto, Per! We heathen amateurs need someone like
you to help us out!

<img src="graemlins/notworthy.gif" border="0" alt="[Not Worthy]" /> <img src="graemlins/notworthy.gif" border="0" alt="[Not Worthy]" /> <img src="graemlins/notworthy.gif" border="0" alt="[Not Worthy]" />

hyzer

Per, thanks for stopping by!
<img src="graemlins/notworthy.gif" border="0" alt="[Not Worthy]" /> <img src="graemlins/notworthy.gif" border="0" alt="[Not Worthy]" /> <img src="graemlins/notworthy.gif" border="0" alt="[Not Worthy]" />

Amazing time we live in, watch a show at night with my 12 year old son, read posts the next day by one of those featured in the show!

Per Ahlberg

Gosh! (There doesn't seem to be a "glowing with embarrassment" graemlin available, so you'll have to imagine one...) To receive such plaudits from the Vorlon Ambassador AND the illustrious author of "Well, that just about wraps it up for God" and other blockbusters is almost too much! Seriously, I've been consistently impressed with this site: you are doing a great job.

Hyzer: yes, it's amazing how things have changed. I guess the downside is that the creationists also reach people more easily than in the old days, but there you go... If you (or anyone else) have any questions about the programme, why don't you post them in this thread and I'll do what I can to answer them.

In fact, there are a couple of points that were not brought out in the programme (there's never enough time for everything) that might be worth mentioning here:


1)PANDERICHTHYS

In the same stratum that yields Livoniana (the Gauja Formation, borderline Middle/Late Devonian) occurs a tetrapod-like fish called Panderichthys. It is a little further down the tree than Livoniana (and in fact provided the "fish" jaw that I used to contrast with Livoniana in the programme), but it is more advanced than Eusthenopteron - AND it's known from complete bodies. I don't know why the Beeb decided not to include it in the programme (goodness knows I tried to convince them), because it is an almost perfect intermediate between Eusthenopteron and a basal tetrapod. Essentially, it looks like a small crocodile with paired fins instead of legs. I would like to post a picture of it, but would like some advice on how best to do it (format? size?). Anyway, Livoniana is intermediate between this intermediate and the earliest tetrapods (but still not intermediate enough for some people, I guess ) .


2) THE GEOLOGICAL COLUMN

It is a curiosity of the Baltic region that the geology is very uncomplicated: you have a complete, orderly succession from the early Middle Devonian to the end of the Devonian, with one stratum lying neatly on top of the other and the whole stack dipping gently to the south. It is easy to follow the sequence along the river valleys (where the sandstones form low cliffs) and in boreholes. Now in the Baltic sequence we have, at the bottom (for example in the Arukula Formation) lobe-finned fishes but nothing particularly tetrapod-like; a little higher up (Gauja Formation), Livoniana and Panderichthys; a little higher still (Ogre Formation), Obruchevichthys - one of the two earliest and most primitive (fragmentary) tetrapods in the world; and finally, at the top (Ketleri Formation), Ventastega, a tetrapod closely similar to Acanthostega and of the same age. (Ventastega provided the "tetrapod" jaw that I compared with Livoniana in the programme). Now isn't that neat? The whole fish-tetrapod transition stacked up in proper order, like shirts in a drawer...

Bye for now, Per

hyzer

Per Ahlberg: “. . . . AND it's known from complete bodies. . . .”

Then it is in deed unfortunate that you did not prevail as I actually was thinking while watching the show that the “door was open” for a creationist to excuse the entire cladistic (sp?) exercise because only jaw bones were being compared.

Per Ahlberg: “I guess the downside is that the creationists also reach people more easily than in the old days, but there you go”

Very true. But then, IMHO, creationists come off much worse when they put their thoughts in writing and post them on the internet.

Thanks for the great information in your additional post!

Kosh: “I know hindsight is 20/20, but it's funny that in the end, after determining that the legs evolved in the water, not vice versa as they had thought, they were showing live footage of salamanders as an example. It was right there in front of us all along!”

Yes! I had the same thought while watching the program. In fact I was struck by how much the profile of the head of the salamander shown is similar to the profile of the heads of Ichthyostega and its brethren (which makes sense).


Correction to my opening post – I should have written “Paleontologists”, not anthropologists.

Kosh

Pardon my paranoia, but I've been dealing with
corporate politics for almost 20 years now...

Since my brother works in Hollywood, I'm aware
that the people working on any given production
can have a diverse set of personal opinions. Ie,
most of them are there as an assigment to work
on the job. That doesn't mean they agree with
the program itself. There could very well be
hardcore YECs working on these Nova programs.

Have you ever seen evidence that perhaps decisions
not to include some details (such as the example
you gave) could be motivated by personal agenda?

Per Ahlberg

Quote:

Yes, it is a pain in the neck that 'Horizon' left out Panderichthys. One thing you learn quickly in this game is that you can NEVER prevail against the producer if they have set their mind on something; you have the "armageddon option" of walking out on the project, but that's it - and that didn't seem appropriate in this case.
There was an agenda at play with the BBC alright, but not a creationist one. The last few seasons of 'Horizon' have increasingly gone for a rather low-brow, sensationalist take on science. In this particular case, the producer had made up his mind that he wanted to do a "missing link" story, blithely disregarding my (and Jenny's) protests that palaeontology doesn't work like that. So rather than give a nuanced depiction of how, in the last decade, NUMEROUS pieces of evidence have come together to fill almost all the major gaps in the fish-to-tetrapod story, we ended up with an excessive focus on the exciting but very fragmentary Livoniana.
(Oolon may have seen last week's programme, which featured the controversy around the alleged bird-dinosaur intermediate "Archaeoraptor" from China, that turned out to be a composite pasted together from different fossils. Again, there was the same problem: the Archaeoraptor story itself was treated quite nicely, but there was no hint that numerous feathered dinos and dino-like birds (Sinosauropteryx, Caudipteryx, Protarchaeopteryx, Archaeopteryx, Rahonavis, etc.) are known from China and other parts of the world. The viewer was given the idea that Archaeoraptor provided the only evidence that birds evolved from dinosaurs - which is both untrue and highly misleading. In the end they agreed that birds probably ARE descended from dinos, and showed that the Archaeoraptor forgery had actually been stitched together from a couple of different but genuine dino-bird intermediates, but I still felt the subject had been misrepresented.)
NOVA, on the other hand, can be exonerated completely. Everything I've heard from them, and everything I've seen on their website, suggests that they have been building up the science content of the programme rather than reducing it. The website even features a computer simulation of natural selection. Still, they could obviously only work with the material they were given.


Per