But we do have a massive impact on the places we live. On the Galapagos program the other night he was saying that by people coming to them to live and visit that we have reversed evolution in a species of bird (damn it I wish I could remember what bird it was

) as it had started to evolve into two separate sub species that was determined by the size and shape of their beak (beak getting smaller so it can get food from the cracks in the rocks) due to the type of food they would eat, but since "we" have been there and leaving our food scattered around they no longer need to have the smaller beaks to get into the cracks in the rocks and this evolutionary trait is stopping.
They also filmed lonesome George just before he died and the death of that species was solely down to us (as well as many, many others)
Edit; just remembered, it was a finch