Friend, Just be intelligent to be aware of the fact that the events you have mentioned are dating back to over around 10 lakh years...There could have been a kind of race which is between monkeys and humans.I am not saying this is the way, but could have been the case.
So have an open mind, as no one can intellectually understand these things, particularly when the events are supposed to have happened ages before...
For that matter, its the same with any religeous events. You just will not be able to find any logic in that with our knowledge derived from present...
