rationalskepticism.org

asyncritus wrote:

Oldskeptic wrote:

Tiktaalik didn't have legs. It had front fins like what might be expected in a species transitioning between water to land. It also had gills and rudimentary lungs. Something else expected of a transitioning species. And it had a neck found in land animals but not modern fish.

The cool thing about science and scientific hypotheses is that they make predictions, and Tiktaalik was one of those predictions. Not just the morphology but also where it would be found in the fossil record. That is why tiktaallik is important.

Tiktaalik may or may not be the direct ancestor of all tetrapods. It was a lobed finned fish with some tetrapod features. It could be a branch that went completely extinct leaving no descendent lines, but that doesn't mean that other lines similar to tiktaalik like fish didn't go on to eventually produce tetrapods.

You may believe that if you like, but I wonder if you remember the Latimeria debacle?

Here's something from Henry Gee, an editor of Nature, Jan 2010 that finishes off Tiktaalik as an ancestor of the tetrapods.

The best discoveries are those that overturn current thinking, revealing that what we thought, only yesterday, to have been a coherent and complete picture, is in fact a void that no discoveries can yet fill. Such is the report in tomorrow’s Nature (Niedźwiedzki et al., 463, 43-48, 7 January 2010) of footprints left by tetrapods (four legged land vertebrates) eighteen million years older than the earliest known tetrapod fossils, and ten million years older than the fossils of the creatures thought to be the closest relatives of tetrapods. A fairly complete picture of tetrapod evolution, built up over the past twenty years, has been replaced by a blank canvas overnight.

Tough luck, guys.