I don't believe that men alone are capable of having two hands. Can't horses, cows, sheep evolve? And can it be, moreover, that of all the monkeys only one species can evolve, and all the others are incapable of evolving? In a million years, ten million years, will horses, cows and sheep still be the same as those today? I think they will continue to change.
So, Mao held the Joe Sixpack view of evolution: it is all about becoming intelligent, hair-challenged apes. It may be unremarkable that Mao, as a non-scientist born in 1893, was ignorant about Darwinian principles, but given his near-divine authority, those words must have compelled many Chinese to accept pseudoscientific garbage as unquestionable truth. At the time, it probably didn't have the disastrous practical consequences as Lysenkoism in the USSR, but it was philosophically similar and equally anti-scientific. (Of course, Lysenko was Stalin's favorite "scientist".)
What do we have here? The two scariest "atheists", each responsible for deaths of millions, both favored ideas born of navel gazing over science. That is incompatible with the atheism which Richard Dawkins or Sam Harris advocate. Any system of ideas that does not reject theories contradicted by scientific evidence doesn't deserve to be called atheistic, regardless of how loudly its proponents proclaim non-existence of gods. Stalin and Mao were much closer to faith healers than to non-believers.
If you are concerned about the creationist movement's assault on the scientific world view, you need to be aware of the related anti-scientific positions of the worst Communist leaders. The side that wields the "Stalin and Mao" weapon in that battle must change: instead of conservative pundits asserting the atheists' "connection" with the psychopatic dictators, the defenders of science should point out that the fundamentalists are in an "unholy" alliance with the hard-line Communists when it comes to rejecting neo-Darwinian theory of evolution.