Marxism, Internal Critique, External Critique

The stated Marxist critique of Capitalism relies heavily on exposing its internal contradictions, most notably the Class antagonism they invoke to justify Revolution.  However, they not only under-appreciate the effectiveness of a type of external critique, but implicitly apply it themselves.  According to that type of critique, a more comprehensive concept supersedes a less comprehensive concept that it includes.  That criterion is entailed in the Dialectical concept of Sublation, and is utilized by Marxists when they posit that Capitalism is only a transient episode in a Dialectical History.  However, in doing so, they seem to be unaware that their concept of History could be or has been superseded--by the Evolutionist concept, according to which Human history is itself an episode in Natural history, and, so, derived from principles that govern that.  Thus, as effective as an Internal Critique of Capitalism might be, it is itself subject to an External Critique.