Darwin and the Darwinian Revolution, Gertrude Himmelfarb notes that there was a similarity in not only the philosophical intent of Charles Darwin and Karl Marx but also in their practical effect. Here’s an excerpt from her book (Page 421):
When Marx read the Origin, he enthusiastically declared it to be “a basis in natural science for the class struggle in history.” In 1873 he sent a copy of the second edition of Das Kapital to Darwin, who politely acknowledged the gift. “Though our studies have been so different, I believe that we both earnestly desire the extension of knowledge; and this, in the long run, is sure to add to the happiness of mankind.” If Darwin had not the least idea of what Marx was up to or what they might have in common, Marx knew precisely what he valued in Darwin. Recommending the Origin to Lassalle, he explained that “despite all deficiencies not only is the death-blow dealt here for the first time to teleology in natural sciences, but their rational meaning is empirically examined.” The other reason for his interest in the Origin emerged in Das Kapital, where he complained of the abstract materialism of the most natural science, “a materialism that excludes history and its process.” It was his hope that by focussing attention on change and development, the Origin would destroy both the old-fashioned supernaturalism and the equally old-fashioned materialism.