But in a way, it doesn't really have to be explained?
Yes. At least, if you care about being rationally justified in your beliefs...
If God created man, animals, plants, and obviously He used genes to direct development and procreation, just as He uses internal organs to carry out normal life functions, why should it be surprising that there are great similarities?
It's not about mere similarities. It's about the pattern of distribution thereof...
Evolution predicts a very specific distribution: nested hierarchies. And that is exactly the pattern we observe in living things.
"special creation" predicts no such pattern. If anything, it predicts anything BUT such a pattern.
Because it inevitably results in "baggage" and inefficient use of energy and resources.
Not a single human designed product false into nested hierarchies. Not even products from the same manufacturer and brand. Not even single productlines. Take a smartphone model, any smartphone model. iPhones, Samsung Galaxy series, Nokia/Microsoft Lumia series, blackberries,... Not a single one of them falls into a nested hierarchy.
To have a designed product line fall into a nested hierarchy... you'ld have to do it on purpose - and go out of your way to accomplish it.
Especially when things "work"? Each creature when it reproduces, reproduces in kind. So what does it matter if there are great similarities, as long as you don't have dogs inadvertently giving birth to kittens.
If dogs would produce cats, evolution would instantly be falsified.
Tell me... what would falsify special creation?
Likewise, should it matter if man, elephants, tigers, and mice all breathe with lungs, since lungs "work"?
What about whales and dolphins? Why give those lungs? Why not gills, like all other "fish"?
Would it be more "proof" of creation if every creature had its own kind of breathing organs?
Yes.
I suppose it would, but apparently that wasn't the way God chose to make things happen.
So.... no matter how life looks like... god did it, and that's final? Is that what you're saying?
my faith doesn't rest upon particular interpretations of creation
Good for you. Although I find it curious then, that you seem to have religious issues with scientific consensus of the biological sciences...