mike the wiz writes:
But the evolution of the ancestor's wings is assumed and therefore question-begged.
It isn't assumed. If wings evolved in birds then they would fit into a statistically significant phylogeny, and they do. The evidence demonstrates that wings were present in the common ancestor of birds.
Vestigial features in and of themselves do not evidence evolution. What does evidence evolution is the pattern of vestigial features. We only see vestiges of features that we would expect in an evolutionary tree, such as vestigial wings in kiwi birds. We don't see vestigial features that the tree does not predict, such as vestigial feathers in mammals or vestigial teats in birds.
So then the vestiges themselves wouldn't be designed into them, their original purpose would be designed.
That still doesn't explain why characteristics produce a statistically significant phylogeny.
Whale hip bones for example, they assumed to have been from previous ancestors but, "the case" for the evolution of whales is a poor and circumstantial case. The fact is there can be reasons for why features exist, a lot of the time the vestiges themselves are later found to have uses.
Again, the presence of a vestigial hip is consistent with the phylogeny.