The reason Evolutionists today have any moral sense at all is because the moral code of christian society is still fresh in their subconscious minds.
As it erodes over generations, however, tyrants with no morals at all appear all over the place, and the world falls into darkness. As it is now.
Christianity isn't really all that old, less than 2000 years in fact. The first 300 years of Christianity saw persecution of Christians. The gradual rise of the church saw a decline of the darkness and evil until it's peak. Now the church is in rapid decline and paganism immorality and all it's evil is on the rise.
During almost fifteen centuries has the legal establishment of Christianity been on trial. What have been its fruits? More or less in all places, pride and indolence in the Clergy, ignorance and servility in the laity, in both, superstition, bigotry and persecution.
James Madison, Memorial and Remonstrance against Religious Assessments, 20 June 1785
http://press-pubs.uchicago.edu/founders/documents/amendI_religions43.html