Among its many features, Roberta Estes’ acclaimed book, DNA for Native American Genealogy includes step-by-step instructions, with illustrations, on how to use DNA testing at the four major DNA testing companies to further your genealogy and confirm or identify your Native American ancestors. Among the many other topics is a discussion of Population Genetics and how ethnicity is assigned, as well as an explanation of the differences between Ancient and contemporary Native American DNA. The following except discusses the geographic trends for the Ancient DNA found on both the North and South American continents.