Unfortunately, if you understood absolutely nothing based on the already posted information, and the fine articles by David Glass and Mats Wahlberg, I suspect that further explanations will not help either. But: In my view, the point is not to say that God adds anything to evolutionary biology itself. Although the idea can raise interest in some research questions (regarding the constraints and directionality of evolution, for example), studying these does not require affirming design. Rather, the point is that the affirming all of evolutionary biology is wholly compatible with arguing that the evolution of complex biological functions is better explained on the supposition that God has created the process, than on the supposition that cosmos just happens to have the capacity for this kind of evolution. These are different explanatory questions, or different explanatory levels from evolutionary biology, depending on the preferred terminology.
I disagree! I do not think such a misunderstanding or misrepresentation has been demonstrated, even with Tim’s further posts. In context in the book, the Carroll quote is pretty much just flavor text, showing the history of the idea, and is used to argue only what it says in the quote. I then go on to argue (as does biologist Denis Alexander, the “scholar” mentioned by Tim) that the case is stronger than in the time of Carroll’s article. Nothing much depends on the quote, and I do go on to also discuss reasons for doubting that evolution has a necessary direction. So the careful reader should not be left with a false impression.