The is-ought gap cuts both ways. “God commands X” is also an “is”; you can’t get “I ought to do X” from it without a bridging premise. If Hume defeats evolutionary ethics, doesn’t he defeat divine command ethics too?

A sharp objection. The theistic reply is that the bridging premise is different in kind. A perfectly good being who made you, and to whom you owe your existence, wills X is not merely a natural fact, since goodness and obligation are already built into the description, whereas your ancestors who did X had more offspring contains no normative content at all. Whether that reply succeeds is the Euthyphro question again, which is treated under the transcendent-source exhibit. The honest framing is that both sides face a grounding problem and the argument is about which grounding is more plausible.