Origin: A Genetic History of the Americas

marriage and migration accompanied trading relationships. In combination
with other types of evidence, we might be able to determine whether one or
more individuals from a site came from somewhere else. This information
could potentially tell us a great deal about the ancient cultural practices of
these ancestors.
Answers to these questions interested the tribal representative, who is an
important knowledge holder of their history. They had extensive historical
records and oral traditions, but he had some specific questions that genetic
data might be able to answer. The tribe seemed to me to be a bit less
interested in other questions that I proposed, such as connecting the history
of their tribe to that of the Indigenous peoples of the Americas on a larger
scale, but they were willing to let me investigate them. After a few years of
discussion, we came to an agreement on how the research would be
conducted, how the ancestors’ remains would be treated, how the resulting
information would be shared with the tribe and the scientific community,
and how the raw genetic information would be stored to ensure the proper
respect for the tribe’s sovereignty and privacy.
It had been a long time since I’d worked at the bench, but as I began the
process of decontaminating the surface of the 500-year-old tooth—a soak in
bleach, a rinse with DNA-free water, a 10-minute session in the small
ultraviolet light box on the benchtop—I was relieved to find I still had my
“hands.” Anti-contamination laboratory practices in the ancient lab are
exacting, but I have found that they also translated into excellent
preparation for a coronavirus pandemic. You must never touch your face
with your hands. You must never pass your hands over open tubes, nor
leave tubes or containers with their lids off a moment longer than necessary.
Every time you touch your hands to any surface, you must bleach them
afterward. Every time you finish working in a laboratory space, you must
bleach both the benchtop and the equipment you used. It takes a constant
mindfulness and hours of training to operate in this environment.
Laboratory researchers call anyone who is skilled at working at the bench a
person with “good hands.” In the ancient DNA world, this is mostly
focused on someone who can maintain this mindfulness in preventing
contamination.