Stable isotopes can indicate whether a person consumed more terrestrial or marine foods.

Strontium and oxygen signatures can sometimes provide clues about mobility and childhood geography.

Radiocarbon dating can establish the age of occupation, although calibration and contamination must be handled carefully.

DNA can reveal biological relationships and population histories.

Sediment and pollen studies can reconstruct local environmental change.

None of these techniques is a magic answer, but together they turn an old mystery into a testable set of questions.

The sea-level question deserves similar caution.