But the possibility that some of those contexts might preserve DNA is real, and the techniques for extracting and analyzing such DNA continue to improve.

Another important research direction is the investigation of population structure within the founding period — the question of whether the people who entered the Americas from Beringia were a single, relatively homogeneous group or whether there was already significant population structure within the founding population before the southward expansion began.

The Beringian standstill model suggests a period of isolation that would have produced some internal differentiation within the founding population; how much differentiation, and how it maps onto the subsequent diversity of Native American peoples, is an active area of research.

The ethical dimensions of ancient genomic research will continue to evolve as well.