Roger Fry, the great English art critic, is our best guide to the matter. He explained (in 1894) that modern art corresponds to a dsitinctively modern conception of "the world as process" -- because, post Darwin, "we have exchanged the static for the dynamic position...The species is not longer a fixed and unchangeable type, ethical codes are regarded as part of the varying modes of adaptation of the human species to varying conditions...
In 1867 the novelist Emile Zola began imagining complex family histories that weave throughout his 20-volume Rougon Macquart series, where heredity became a dramatic force determining the fate of his characters -- an early highly disconcerting application of "social Darwinism". A boyhood friend of Emile Zola and Paul Cezanne, Fortune Marion, was an eminent Darwinian; there were Darwinians who cropped up in the social circle of Karl Marx, there were Darwinians who influenced Nietzsche, Bergson and a myriad of others.
In his manifesto, Towards and Architcture (1923) Le Corbusier depended on the Darwinian paradigm of natural selection to explain how progress occured in the realm of architecture and design.
If you're interested, there's a lecture series on Darwin's influence coming up.