Among the biological materials preserved in the ice, Kwäday Dän Ts’ìnchi’s hair provides one of the most temporally specific windows into his life in the months before he died.

Hair grows at a roughly consistent rate — approximately one to one and a half centimeters per month under normal conditions.

Each segment of hair that grows during a specific period incorporates the chemical signature of the diet and environment experienced during that period.

Because the stable isotopes of carbon, nitrogen, sulfur, and other elements are recorded in the hair’s protein structure as it grows, analyzing different segments of a single hair shaft can produce a sequential record of dietary and environmental changes.

This is what researchers attempted with Kwäday Dän Ts’ìnchi’s hair — analyzing multiple segments from different positions along the hair shafts to reconstruct how his diet and environment had changed in the period leading up to his death.