I would rather label the whole enterprise of setting a biological value upon groups for what it is: irrelevant, intellectually unsound, and highly in… - Stephen Jay Gould

In France, Étienne Geoffroy Saint-Hilaire attempted to portray the skeleton of vertebrates as a set of modifications upon an archetypal vertebra. In the 1820's, Geoffroy extended his ambitious plan to include annelids and arthropods under that same rubric. ...Vertebrates support their soft parts with an internal skeleton, but insects must live within their vertebrae (a reality, not a metaphor, for Geoffroy). This comparison led to... the claim that a vertebrate rib must represent the same organ as an arthropod leg - and that insects must therefore walk on their own ribs!

Iconography becomes even more revealing when processes or concepts, rather than objects, must be depicted—for the constraint of a definite “thing” cedes directly to the imagination. How can we draw “evolution” or “social organization,” not to mention the more mundane “digestion” or “self-interest,” without portraying more of a mental structure than a physical reality? If we wish to trace the history of ideas, iconography becomes a candid camera trained upon the scholar's mind.

Details are all that matters: God dwells there, and you never get to see Him if you don't struggle to get them right.