I'm sitting here reading this like... "But wait you have to have Macroevolution with microevolution..." What the -blam!- don't you understand about it? After many many many little changes occur in an organism, and you look and the current one compared to its ancestor say 100,000 years previous, the animal has evolved to fill a new role. What the -blam!- do you not understand about it? Say my child Mucroevolved a resistance to, I dunno, HIV. Now my child spreads this trait (assuming it is dominant) throughout many members of our species. Now say, everybody gets really horny and we all have one massive orgy and all get HIV (except for those immune) and we all die except for them. That would be similar to your Pesticide example. Now this variation in our species repopulates the Earth. After many hundreds of years, they develop a resistance to another disease that wipes out all others. This process goes on for 5,000 generations. You should have a species genetically different enough at the end to be considered no longer "homo sapien" Excuse me for the -blam!-ing terrible example, but I am current falling sleep and need rest. Good night.