What do you means there are no evidence of which the Tiktaalik evolved from?
Of course there are evidence, you are simply just do some research on the Tiktaalik. You expect everyone to answer your questions, but all I see from you is nio attempts to some works yourself - no reading, no research and hence NO UNDERSTANDING.
Plus, what explain to you, you just dismissively hand wave them away, and then ask the same question again.
it is exhaustive for other to repeat the explanation from your questions and you doing no research on the matter.
I am not giving you whole answer, so I would suggest that you looked them up.
You wanted to know about what came before the Tiktaalik, then you should start with following in term of timeline:
The superclass Osteichthyes (bony fish, Devonian), there are 2 main classes of bony fishes:
- class Actinopterygii (ray-finned bony fish) Most of fishes you would find in the seas, oceans, and freshwater are ray-finned fishes, that existed today modern actinopterygians - swordfish, tuna, salmon, pike, seahorse, etc. There are just too many actinopterygian orders, familie, genus and species to list them here.
- class Sacropterygii (lobe-finned bony fish)
- subclass Actinista
- class Dipnoi
- clade Tetrapodomorpha (this is the group that you should be interested in)
- genus Eusthenopteron
- genus Panderichthys
- genus Tiktaalik
- genus Elginerpeton
- genus Acanthostega, stem tetrapod
- genus Ichthyostega, true four limbs, hence tetrapod
You should considered the Eusthenopteron, Panderichthys, Tiktaalik, etc, as clades. What the species to Eusthenopteron, Panderichthys, & Tiktaalik showed, are increasing skeletal development of the lobe-fins into something becoming more limb-like.
Do some reading, research from Osteichthyes to Sacropterygii, and then all the tetrapodmorpha sacropterygians (including the Tiktaalik, Acanthostega & Ichthyostega, then you will understand where the amphibians come from, followed by true terrestrial tetrapod vertebrates, the amniotes, which are ancestors to all modern reptiles, birds and mammals.
edit:
As books would be expensive, then Wikipedia & Google are your friends.
All those list of superclass Osteichthyes, class and the clades to the Sacropterygii (including Tiktaaki), can all be found in Wikipedia articles, and these include cited scientific papers in the bibliography, references, footnotes. So there are wealth of information from wiki articles.
do the research yourself.