[tortoise]

The simple answer is that it was designed by the same creator, the one who created the heavens and earth.

You merely assert that this explanation is "simpler" using some vague definition of "simple" that you've invented. By every useful rigorous metric of "simpler" we have, your explanation isn't.

Prove that your answer is "simple". No reasonable person is going to take it on faith.

[Echo Talon]

Well we have a man stating that minerals and nature have a tendency for symmetry, and looking at the skeletons of numerous animals that same symmetry applies. Thats is the creators "signature" look at artists great works they all have similarities and traits, and this is no different.