is it really so hard to believe that an omnipotent being would re-use parts/ideas?
You talk up human physiology in your post, but if you wanted to design an upright walking creature from whole cloth, you wouldn't use our skeleton. One of the reason we get backaches and other such things is because our bodies are not "well designed" for walking erect. Oh, we can do it, and we can do it with fairly minimal problems, but our skeletons are not what you would build if you wanted to make a living thing walk on two legs.
Humans are "good enough" at walking erect, not the perfection at it you would expect a supreme being to bring into existence.
It isn't so much that it's hard to believe that God might reuse parts/ideas, but that things are not as perfect a fit at doing what they currently do as they would be if they were created by an omnipotent being.
according to the bible God created animals "according to their kind" im sure that some animas have adapted over time, but not changed into somthing else completely.
That's actually one of those misconceptions people often have about species, biology and evolution.
What exactly is "something else"? What does it mean for a species to become "something else"? How do you know when it is "something else" from what the population used to be?
For multicellular life, the definition of species is this: two populations that can interbreed and produce viable offspring are the same species. For biologists, it is easy to know when something has become "something else": when one population can no longer interbreed with another.
Evolution does not predict "chimeras": that is, some half creature, like a horse/hippoptamus, or a half-crocadile/half-duck or some other such absurdity. What makes the general diversity of life work is the successive accumulation of changes that eventually makes two populations that used to be of the same species no longer able to interbreed. Eventually, further changes will differentiate the two populations to the point where you would not immediately recognize them as being related without detailed study.
Evolution predicts transitional forms. Not "one thing we currently know now turning into something we also currently know now," but species which share common characteristics from both the parent and the evenetual child. They don't have to actually be the direct parent of that child, however.
Take Archeopteryx, for example. It is a transitional form between dinosaurs and birds. However, as we currently understand things today, it is not necessarily the single species from which all modern birds are derived. It is more likely an extinct sibling of the earlier species. Transitional species do not have to be the direct root of that particular branch of the tree; it simply needs to share the common characteristics of the two siblings. For example, it shares feathers with its avian cousins, but it shares the teeth and hand bone structure of dinosaurs. Indeed, one Archeopteryx fossile was found that had so faint feather fossiles that it was initally classified as a particular species of dinosaur raptor before they corrected their mistake. Archeopteryx was a child of the same parent species that started the avian line as we currently understand it.
Life is very malleable. It is not as rigid and set as it appears, and even the apparently rigid distinction of "species" is in question. For example, there is something called a "ring species". That is, you start with a population in environment 1. Some of the move to environment 2; once in a new environment, they develop different characteristics unique to that environment. However, these are not sufficient to speciate them, so they can still interbreed with those in environment 2. Some from #2 move to environment 3, where again they develop new characteristics. These can interbreed fully with those from environment 2. And we do it again with environments 4 and 5.
If environment 5 happens to be adjacent to environment 1 (it forms a "ring"), what often happens is that the guys in environment 5 are so different that they cannot actually interbreed with those in environment 1. Even though they can interbreed with the ones in environment 4, who can interbreed with those in 3, who can interbreed with those in 2, who can interbreed with those in 1. But the ones currently in environment 5 cannot directly interbreed with those in environment 1.
This is a well known and documented phenomenon.