Darwin had a basic working draft of evolution by means of natural selection by 1838. It wasn't until 1858, twenty years later, that a letter from Wallace got him off his butt, and good old male primate competition overcame cowardice, laziness and groupthink, and he got to work. In between these two dates, Marx's Communist Manifesto was published in 1848.

http://en.wikipedia.org/wiki/On_the_Origin_of_Species

"Arguments based on natural science, when applied to social questions, must almost always lead to wrong conclusions" - this, from a 20th century Dutch Marxist, attempts to pre-empt 'bourgeois' Darwinism. Strange that 'scientific socialism' should attempt to separate man from the animals, following religion, and rejecting Darwin's most revolutionay insight.

http://www.marxists.org/archive/pannekoe/1912/marxism-darwinism.htm