The original thread was somewhat hijacked, so we never really got to discuss this case without the interruptions. The posts in that exchange was moved to: Nonlin's Case Against Common Descent.
At this point, we can reopen discussion on the original post.
Copying a response from the split that was not meant to be a response to Nonlin, if that is OK? (If not, please delete.)
Tiktaalik is one of my favorite examples. I use it in reply to people claiming there is no experimental evidence to support evolution.
There was a gap in the fossil record between fish and land-walking tetrapods, and based on evolution hypothesized that such a creature should have existed. Shubin and others examples examined geological records for location of the right age and environment where fossils of such a creature might be found. After several years of searching they discovered the fossils representing the creature we now know as Tiktaalik. This constitutes an experiment based on a prediction of evolution: hypothesis, gathering of data, and confirmation of the prediction. This is very repeatable - we can (and do!) search for other fossils not yet known but predicted by evolution.