Re: Tiktaalik

[David Marjanovic <david.marjanovic@gmx.at>]

> I'm talking body plans.

Yeah -- what, if anything, is a body plan.

> No matter how awe-inspiring a lungfish's
> cakehole is, it's not going to help it move around on land.

No matter how awe-inspiring a tetrapod's hand or foot is, it's not going to 
help it eat anything even as hard as a cornflake. Look at the Paleozoic 
diversification of lungfishes...

> Oh no!  Not those horrible "ranks"!  I'm not talking typology here (heaven
> forfend!), but transformations involving locomotion in (or on) two 
> different
> kinds of media.

In this respect *Tiktaalik* is no more spectacular than your average 
frogfish.

> Tetrapods (including ourselves) are still just uppity
> lobe-finned fish, and birds will always be theropods.  But both 
> transitions
> involved major transformations, associated with water-to-land and
> land-to-air.

I keep hearing "major". :-)

> Not convinced?  Ask yourself this: Why did _Nature_ magazine dedicate a
> combined 18 pages to the discovery of _Tiktaalik_?  It made the cover too.
> It was not just because this critter was "photogenic" (though it was that
> too).

Because our own ancestry is involved (hey, I'm not interested in lungfish 
either), because more people are interested in the transition to land (which 
was far away from *Tiktaalik* -- try *Pederpes* at best) than the transition 
to durophagy -- which again may just be because we're not lungfish --, and 
because, as I wrote, "the changes are photogenic": an extremity with fin 
rays and a wrist joint is new to science.