Every modern human alive today carries genetic signatures of every population their ancestors passed through, mixed with, diverged from, or replaced.

Ancient genomes are like snapshots of those populations frozen at specific points in time.

When geneticists sequence an ancient genome, they can ask questions that would have been unthinkable thirty years ago.

They can determine which modern populations the individual is most closely related to.

They can identify how much ancestry the person shares with archaic humans — Neanderthals, Denisovans, and potentially other populations.

They can estimate, within certain ranges, when population splits occurred and when admixture events happened.