For the assertion that Darwin killed God to be true, there would have to be no pre-Darwin atheism; this is refuted with the example of de Sade.
Indeed, atheism can be found in all periods of human history, although it is particulary profound in the areas of Christendom that are called 'Protestant'.

The Christian God was devaluing its own divinity long before Darwin.
Also, there are points of contact between Darwinism and Christianity - e.g., the teleology of progress [something that Christianity and darwinism have in common, but generally rejected by Paganism which tends to a cyclical paradigm].
PROTESTANT Christianity paved the way for Darwinism.

That Christianity [like other monotheisms] had to fight "Wars of Conversions", shows that its concept of divinity is abhorrent to large swathes of the human population: and yet, every people has its own gods!
The Semitic Monotheistic religions have done more to terrorise man OUT of his sense of Divinity than any other theism.