One could accept common descent, but the reason I’m a creationist is that it seems to require miracles to make it possible.
Microtubules are critical to many living organisms. Yet these microtubules have polarity (as in like a one way highway). The polarity is achieved as described here:
Microtubules are built from subunits—molecules of tubulin—each of which is a dimer composed of two very similar globular proteins called α-tubulin and β-tubulin, bound tightly together by noncovalent interactions. The tubulin dimers stack together, again by noncovalent bonding, to form the wall of the hollow, cylindrical microtubule. This tubelike structure is made of 13 parallel protofilaments, each a linear chain of tubulin dimers with α- and β-tubulin alternating along its length (Figure 17–12). Each protofilament has a structural polarity, with α-tubulin exposed at one end and β-tubulin at the other, and this polarity is the same for all the protofilaments in the microfilament. Thus the microtubule as a whole has a structural polarity: the end with β-tubulin showing is called its plus end, and the opposite end, which contains exposed α-tubulin, is called the minus end.
Alberts, Bruce. Essential Cell Biology (Fifth Edition) (p. 581). W. W. Norton & Company. Kindle Edition.
So, is gene duplication a good explanation for the origin of the alpha and beta paralogs of tublin (the material in making microtubules)?
Well, if the paralog pair is missing, then how is polarity achieved? Seems the paralogs are created, no matter what phylognetic story is told. If we don’t assume creation, there is the mechanistic problem of having some sort of alternate for microtubules with structural polarity.
Such examples make it hard to believe common descent could proceed without miracles. And if one is willing to accept miracles, then how is this different than special creation?