Why do we sign our names? When did autographs first acquire value? How can a squiggle both enslave and liberate? Signatures often require a witness — as if the scrawl itself is not enough. What other kinds of beliefs and fantasies justify our signing practices? And how have they influenced digital culture, metaphors of animal life, and conversations about biological and climatological “signatures”?

Signature addresses these questions and more as it roams from a roundtable on the Greek island of Syros, to a scene of handwriting analysis conducted in an English pub, from a wedding in Moscow, where guests sign the bride’s body, to a San Franciscan tattoo parlor interested in ideas associated with “primitivism” and their legacy in anthropology .

The history of signatures encompasses ancient handprints on cave walls, the branding of slaves, Victorian autograph hunters, a forgotten medical habit of signing patients’ bodies, hip-hop lyrics, epigenetics, legal challenges to electronic signatures, ice cores harvested from Greenland, and tales of forgery and autopens.

A signature is unique. Autographs are a way of extending the self, scattering its presence throughout the world. At least since Paleolithic times, however, signatures have also been sites of emergent community, where an individual vows allegiance to something greater.