Are you just "an evolved animal" or a man?
It is a very telling point and a very true one and it shows quite well the importance of this debate. If evolution is true, then life has no purpose. The lowest and basest instincts are therefore excusable. Eugenics, mercy killing and even abortion become legitimatized. Even mass murder as a form of 'helping' natural selection becomes viable.
One must doubt if any society can survive under such terms. One must doubt if any species can survive which acts in such a way. For the above is a prescription for destruction not for creation. What man needs is hope, not despair in order to better himself and evolution only provides despair.