You've saved me some bucks on Stevens & Price. There's an explosion of EP material these days; I appreciate any triage information.
Incidentally, I found a neat essay by Stephen Gould, "Male Nipples and Clitoral Ripples" (aka "Tits & Clits") in Bully for Brontosaurus.
Gould also has a classic piece someplace on spandrels and St. Mark's Cathedral and evolutionary adaptations. Briefly, some physical or behavioral structures may exist because they "fill in" between adaptations. A spandrel in architecture is the triangular space between adjacent arch supports and the horizontal plane of the dome above. The architect didn't particularly want a triangle but had to fill in the space between the dome bottom and supporting columns.
Spandrels can be beautiful and can take on new roles (exaptations? another Gould term) apart from their original "design necessity."
Good luck in Sheffield!