This is a companion discussion topic for the original entry at https://biologos.org/blogs/guest/scientists-find-feathered-dinosaur-tail-preserved-in-amber
This definitely clarified some of my questions about the AIG article. Thank you very much!
Earlier, I referred to Archaeopteryx as a transitional fossil, but I want to clarify what that means when thinking about evolutionary change in groups of organisms. It is easy to over-simplify, and think that evolution acts in a linear fashion, like this: Instead, evolution is better visualized as a branching tree. As lineages evolve and diversify, they become distinct from one another, which is represented by new branches. Not only does the tree branch but, over time, it is also pruned as species or entire lineages (e.g. all Tyrannosaurs) go extinct. - See more at: http://biologos.org/blogs/guest/scientists-find-feathered-dinosaur-tail-preserved-in-amber#sthash.1KlrXU6N.dpuf
Evolution is truly non-linear, but this is not explained. Evolution is determinate, but non-linear, because Natural Selection is determinate, but non-linear. Natural Selection is determinate, but not linear, because the ecology is determinate, but not linear.
Ecology and evolution is moving toward diversity, rather than complexity as was suggested before. The determinate, but non-linear direction of evolution is strong evidence that it is guided by the ecology and God.