Over the last 20k years, humans have lost about one tennis ball sized hunk of brain. In that time, we've seen the advent of blue eyes and a decrease in the ability of adults to digest milk due to absence of the required chemicals. Human genetics and preserved human remains have clearly shown more significant development over larger time periods. The idea that humans are a static life form is proven to be false. And, the changes are explainable by evolution - not any other proposed means.