Origin: A Genetic History of the Americas

archaeologists as Anzick-1 (the two-year-old) and Anzick-2 (the seven- or
eight-year-old who was buried there later). Anzick-1 was special not only to
his parents and relatives (both in the past and across time), but also to the
scientific community across the world. His remains were dated to between
12,707 and 12,556 years ago, making him the oldest known person in the
Americas—the only person who lived during the Clovis period whose
remains are known to have survived to the present day. His genome was
also the first ancient Native American genome to have been completely
sequenced, and it has given us important insights into the First Peoples’
movements into the Americas.
Anzick-1’s complete nuclear genome—and those from additional
ancient individuals that were sequenced in later years—shows us that
shortly after the LGM the family tree of the First Peoples split into two
major (and one minor) branches.
The minor branch, which diverged between 21,000–16,000 years ago, is
currently represented by a single genome from a woman who lived on the
Fraser Plateau in British Columbia—known as the Big Bar Lake site to
archaeologists—about 5,600 years ago. The fact that her lineage split before
the two other major branches may reflect the divergence of her ancestors
from other First Peoples as they were moving southward out of Alaska.
One major branch, which included Anzick and his relatives, became the
ancestors of many Native peoples of the present-day United States and
everywhere south of that. This branch is referred to by geneticists as SNA
(Southern Native Americans). The other branch, which is ancestral to
populations of northern North America, including the Algonquian, Salishan,
Tsimshian, and Na-Diné, is referred to by geneticists as NNA (Northern