Obscuring of human origins

Hi, I'd like to ask about the last sentence of the paragraph below.

Particularly the meaning of "served" and "obscuring of human origins"

Thank you in advance!

------------

What if Bryan and others of his generation had chosen to object to eugenics rather than evolution, to social Darwinism rather than Darwinism? The textbook at issue in the Scopes case, after all, was titled A Civic Biology, and it urged sterilization for the mentally impaired. “Epilepsy, and feeble-mindedness,” the text read, “are handicaps which it is not only unfair but criminal to hand down to posterity.” What if this had been the focus of Bryan’s objection? Mencken doubtless would still have mocked. But the moral and theological priorities of evangelical Christianity would have turned out differently. And evangelical fears would have been eventually justified by America’s shameful history of eugenics, and by the more rigorous application of the practice abroad. Instead, Bryan chose evolution—and in the end, the cause of human dignity was not served by the obscuring of human origins.