Your DNA can help scientists tell the history of migration patterns across post-colonial United States, a new study revealed.
Researchers from Ancestry, a Utah-based genealogy company, collected more than 77,000 spit samples taken from customers in a span of five years. They also gathered information about the customers' family trees.
All these genetic data were used by Ancestry to trace and map out more than 60 genetic communities that emerged in the US from the 1800s to the 1900s.
"We're all living under the assumption that we are individual agents," said study lead author Catherine Ball. "But people actually are living in the course of history."
Figuring Out Migration Patterns
Prior to the Ancestry study, scientists have had a clear picture of what pre-colonial migration patterns looked like in North America. However, the arrival of European settlers in the continent made everything more complicated.
The new report changes everything, said Ball. Because of their large trove of genetic data, she and her colleagues were able to map out the structure of migration patterns in the country, as well as annotate the structure with the people they were descended from.
The team began by pulling out subsets of closely related people based on the thousands of spit samples they collected. In this analysis, the individual appears as a dot while the genetic relationship appears as sticks.
Shifts in Migration
Ancestry researchers then teamed up with a Harvard historian to help corroborate historical observations and understand why communities migrated in ways they did.
Apparently, race and religion had powerful impacts in preventing the "gene flow."
From these maps, they found that genetic communities were similar from Louisiana to Maine. The shift in communities happened when descendants of French colonists known as Acadians moved to Louisiana after the French and Indian War.
There were also Germans in Iowa, Irish Catholics in the Eastern Seaboard, and Mennonites in Kansas.
The Value of Genetic Studies
DNA studies that map out genetic communities have real applications for medical research.
For instance, a lymphoma study that focuses on patients in Miami will not have the same results as a study in Minnesota. This happens because populations have different genetic makeups, and these variations can be valuable in building personalized immunotherapy drugs, cancer treatments, and other gene-targeted treatments.
Meanwhile, Ancestry is planning to integrate the findings of its study into test results, which is expected to launch in spring 2017.
Details of the study are published in the journal Nature Communications. You can view the mapped-out results of the Ancestry study below.