One of the eternal problems of philosophy concerns the origins of normativity. Where do oughts come from? What makes it ever intelligible to say that something should be the case?
One common response is to invoke magic. This response is disturbingly widespread, and that it is perhaps not surprising in this area, where other responses are so hard to come by.
Another common response is skepticism. There really aren't any oughts. Or we invent them in some way. Skeptical approaches tend to be motivated by opposition to magical approaches; the magical approaches can't be right (a point I sympathize with), and there aren't any good alternatives, so there can't be anything here at all.
The problem with the skeptical approach is that normativity runs very deep. There doesn't seem to be a way to talk about something so basic as beliefs being true or false without some notion of how beliefs ought to function, and whether they are or are not functioning as they ought. Of course, some skeptics speak of inventing oughts rather than of their outright absence, but what counts as inventing an ought? There is no apparent way to identify norms except by applying norms for norms.
I am myself of the opinion that the only way to break out of the circles of our understanding is via magic (and so that it can't be done, since I don't believe in magic), but skepticism involves an especially tight circle, and size matters when it comes to circles. The bigger the better; coherentism and holism are better than localized self-justification. And there is a candidate for broadening the circle and accounting for norms. Evolution provides an account of goal-directed behavior which is independent of human invention. There are still circles if evolution is taken as the origin of our goal-directedness (our knowledge of evolution depends on our norms of knowledge), but they're more like big coherence circles and less like little vicious circles.
Perhaps this explains why believers in magic are so opposed to evolution. Evolution eliminates the need for magic at a very deep level, far more fundamental than the level of opposition between most scientific theories and most magical theories. But, of course, there is no magic, and anyway invoking magic only introduces the problem of explaining the magicians, which will enmesh us in the same circularity problems we were trying to avoid. The only real alternative to evolution is skepticism (or perhaps more reasonably agnosticism; we simply don't know where norms come from if they don't come ultimately from evolution).