Good Lord, talk about massaging the data...
Detecting DNA for Native Americans is particularly tricky because there is an absence of Native American DNA available for comparison. This is in part because Native American leaders have asked tribal members not to participate in genetic databases.
“The tribes have felt they have been exploited,” explained Lawrence Brody, a senior investigator with the Medical Genomics and Metabolic Genetics Branch at the National Institutes of Health. “The amount of genetic data that is available from Native Americans is sparse.”
To make up for the dearth of Native American DNA, Bustamante used samples from Mexico, Peru, and Colombia to stand in for Native American. That’s because scientists believe that the groups Americans refer to as Native American came to this land via the Bering Straight about 12,000 years ago and settled in what’s now America but also migrated further south. His report explained that the use of reference populations whose genetic material has been fully sequenced was designed “for maximal accuracy.”