That's a dodge, and you know it. The vast bulk of what's taught in biology does not need macroevolution held in order to teach it. It's often sprinkled into the discourses, but it's usually as necessary to the point as a piece of coal is to a Christmas tree.
Oh yeah, the central and unifying principle is a dodge.
The vast bulk of what's taught in biology does not need macroevolution held in order to teach it.
You don't need Newton's laws to teach astronomy either. You can simply describe planets and stars and galaxies. You can even get a pretty fair prediction of planetary positions in the sky using purely empirical equations, such as those of Ptolemy. However, you will have no fundamental understanding of the cosmos, nor any way to predict anything that varies from the circumscribed conditions of your empirical equations. Ditto with evolution; you can teach classification of organisms, and genomics, and homologies, but none of them make any sense.