No one disputes that Marx was an atheist. But it's just plain silly to claim that he was a "darwinist." History is against you. Marx was writing about communism and running around as a communist agitator years before Darwin ever wrote about evolution. Nothing Darwin wrote ever found its way into the later work of Marx (Das Capital).
Marx was a contemporary of Darwin's. So was Alexander Graham Bell. So was Thomas Edison. So was Robert E. Lee. So what? As I explained earlier, the only known "connection" between Darwin and Marx is that, late in his career, Marx tried (without success) to cash in on Darwin's fame by getting Darwin's consent for a book dedication. He may have tried to dedicate that book to other famous people too, but this means nothing. The book (Das Capital) had nothing to do with biology.
If Darwin's theory can be said to have influenced anything in the world of economics (which it didn't), the creationists usually come up with stuff like this:
DARWIN'S INFLUENCE ON RUTHLESS LAISSEZ FAIRE CAPITALISM (Institute for Creation Research). But even that isn't true in a cause-and-effect way, because Adam Smith published Wealth of Nations in 1776, a wee bit before Darwin's Origin of Species appeared (in 1859).
Your attempt to blame ol' Darwin for all the ills of the world just isn't supported by any facts. Consider this:
1. There were atheists before Darwin (such as Socrates) and after him (like Ayn Rand). Obviously, from those two examples, atheism can exist without communism. Or with it (Marx). But it's like having red hair -- there's no causal connection between atheism and communism.So now, after all this, wouldn't you agree that Marx's work wasn't "darwinist."2. There were communists before Darwin (for example the Spartans and the Mayflower settlers) and they weren't atheists. From those two examples, it's obvious that communism can exist without atheism. Or with it, as in the Soviet Union. Again, it's like having red hair. No causal connection.
3. Stalin hated Darwinian evolution and executed biologists who disagreed with him. His favored biologist was Lysenko, who was anti-Darwin.