Both would be staggeringly complex, but only one is likely.
The best argument against human evolution is that we don't act as if we are product of evolution. We do however act according to what is revealed about us in the Bible.
I'm not clear what is meant by,
we don't act as if we are product of evolution.
The fact is, we live in a world in which what we can measure, analyze, investigate, demonstrate scientifically has greater authority than what we can't. For many religious people, that's just not enough. For them, it really is a question of how they can be absolutely certain, that they are of special, supernatural creation, that there is a unique, divine designer unique to their particular religion excluding all other religions and the supernatural designer gods of those religions.
Common ancestry is readily apparent in the fossil record in terms of shared anatomical, embryological, and molecular similarities. The fact that species have died off as the result of environmental change suggests poor design on the part of your gods.