I'm not sure there were any revolutionary changes during what we describe as evolution. A few of the dramatic environmental changes had a marked effect on the types changes that were retained, but the process consisted of countless infinitesimal tweaks. As we understand our intimate relationship with all forms of life on this planet, and ourselves, the idea that we can create a distinction between mankind and any other part of nature, is isolationist, and destructive, considering our tendency to consider anything we don't understand as a threat. We are all part of the same thread.