One of the main problems Christians have with Evo is the question of human soul.
Christians are quite sure that animals don't have a soul, but if humans evolved from an animal ancestor, at which point did a soul get inserted?
Evo says that there is no drastic difference from one generation to the next - just small differences that make it more likely the offspring will survive to reproduce. So it is impossible to say where our ancestors first became 'sapiens'.