Biological signatures of history: Examination of composite biomes and Y chromosome analysis from da Vinci-associated cultural artifacts

The study presents a minimally invasive workflow—gentle surface swabbing, low-input whole‑metagenome sequencing, taxonomic profiling, and Y‑chromosome analyses—to recover biological traces from Renaissance‑era artworks and archival letters linked to Leonardo da Vinci. Across artifacts, the authors detect heterogeneous microbial and eukaryotic mixtures forming distinct, reproducible composite “biomes” shaped by substrate, storage, conservation treatments, and handling. Exploratory human analyses using ~90,000 Y‑chromosome markers and partial Y‑STR profiling suggest paternal lineages within the broader E1b1/E1b1b clade across multiple da Vinci–associated items, while controls indicate mixed modern contributions. The work demonstrates both the feasibility and limitations of combining metagenomics with human marker analysis for cultural heritage science, offering a baseline workflow for provenance, authentication, and handling‑history studies.