With AncestryDNA (FTDNA)They compare the DNA to one of the most comprehensive and unique collections of DNA samples from people around the world who have taken the test, to identify any overlaps. The overlaps are presented on the maps to show the different matches to our family. DNA matching is a confidence percentage in numbers from 0-100%. This helps to identify which matches to focus on—the higher the confidence the more likely that they are more closely related to our family. The confidence levels are determined by the amount of common DNA two people share with one another. They measure over 700,000 markers in the DNA to analyze the number and length of continuous strands that align.
A feature unique to AncestryDNA is called DNA circles. It shows connections between individuals and family groups who share DNA with you. These circles also contain descendants of your ancestors who you don’t directly share DNA with. Therefore, this feature allows you to extend relative matches beyond what traditional DNA matching can do.
In September 2018, Ancestry updated its ethnicity estimates. As part of the update, my results got a lot more specific. The introduction to the new results are found in this report: “Today, we announce that Ancestry will deliver ethnicity estimates with increased precision to its customers, through a new algorithm that analyzes longer segments of genetic information, marking an important evolution in the way we interpret DNA data. Having built and expanded our DNA reference panel, we have a better understanding of genetic signatures globally, can break down geographic ethnicity estimates with greater specificity and give you a more detailed picture of your origins.”
NOTE: The text and diagrams has been copied from or paraphrased from DNA results from Ancestry.com (© 1997-2018 Ancestry)