Darwin's great gift to science was to show how an explanation could be given for what had been described as the mystery of mysteries, the successive appearance of new species discernible in the fossil record. If new species could emerge from preexisting species by a process of natural selection, it was no longer necessary to suppose there had been what Darwin called independent acts of creation. For atheists and scientific materialists, the plausibility of Darwin's theory was a particularly welcome gift because it could be used to dispel the notion of divine intervention in nature and to challenge the long-cherished belief that each species had been separately and meticulously designed by its Creator. Not surprisingly, there was much apprehension and some downright hostility among religious believers, which in ultra-conservative religious circles still continues today. Darwin's theory has certainly proved divisive within Christendom; but a long tradition of assimilation and accommodation suggests that some at least of Darwin's insights have been received as a gift by religious thinkers as well as scientists.