Oh no, this isn't going to get argumentative at all.
Now, without saying _anything_ about humans, evolution occurs. And by that I mean that the phenotypes of organisms change dramatically over a large number of generations.
This is proven, both empirically (experimentally) and theoretically. Experimentally, this took me about 2 minutes to find on google, I'm sure I could find a more scholarly paper as well -
http://en.wikipedia.org/wiki/E._coli_long-term_evolution_experiment. Without a doubt, species display adaptation to their environments over long periods of time. Of course, it's almost redundant to conduct this experiment. Assuming three conditions, which natural organisms exhibit, evolution is inevitable:
1. Entities that reproduce themselves imperfectly
2. That those imperfections are passed on to further reproductions
3. That those entities are in competition, and that abillity in this competition can be affected by the imperfections.
This can easily be demonstrated in a computer simulation, even one with no other ties to biological organisms - genetic algorithms are an interesting topic.
Thuy, your theory of soul evolution is... intriguing, Rather speculative, but I like it! Your Christian theology may need a bit of work though. There are two (contradictory) creation stories in the Bible, one of which has humans being created after snakes. Also, I've heard claims that both are to be taken metaphorically, but that seems a bit absurd to me.