DNA ancestry companies generate revenues in the region of $1bn a year, and the company 23andMe is said to have sold 10 million DNA ancestry kits to date. Although evidently popular, the science behind how DNA ancestry tests work is mystifying and difficult for the general public to interpret and understand. In this accessible and engaging book, Sheldon Krimsky, a leading researcher, investigates the methods that different companies use for DNA ancestry testing. He also discusses what the tests are used for, from their application in criminal investigations to discovering missing relatives. With a lack of transparency from companies in sharing their data, absent validation of methods by independent scientists, and currently no agreed-upon standards of accuracy, this book also examines the ethical issues behind genetic genealogy testing, including concerns surrounding data privacy and security. It demystifies the art and science of DNA ancestry testing for the general reader.

'Sheldon’s book represents a much needed historical, technical, and ethical treatment of this rapidly evolving and growing industry. It tackles a complex topic that many are fascinated by but few have the educational background to appreciate un-shepherded fully, and does so in a way that is accessible and easy to internalize by the very lay readers who have literally built the entire industry with their demand. His book is not only timely, but way, way overdue … this book is in my view instrumental for anyone considering a genetic ancestry test. If you are a lay consumer of genetic ancestry testing products, it has my highest recommendation for you.'

Tony N. Frudakis - Ph.D., Forensic Scientist, Albuquerque Police Department DNA Laboratory, and Founder DNAPrint Genomics, Inc. (1999)

'This book has it all - science and technology, history, ethics, law, and interesting stories of genealogy. It is classic Krimsky - a truly scholarly endeavor made incredibly approachable. Krimsky goes into sufficient depth to empower the reader with the background necessary to appreciate and understand DNA ancestry fully. The book is comprehensive, describing the key discoveries leading to the modern science of ancestry, including the history and development of the multiple generations of technologies used to achieve the resolution of understanding we have today. Applications of the technology’s uses and misuses are covered, as well as privacy and ethical considerations. Krimsky is a terrific storyteller of individual cases, where people found out they weren’t who they thought they were. He remains in the background throughout as a balanced and unbiased observer. A most interesting and timely book that will inform, entertain, and empower the millions who have had or are considering a consumer DNA test.'

David R. Walt - Harvard Medical School

'How do private companies, like Ancestry.com and 23&me, use DNA to determine your ancestry? How does this differ from forensic DNA used by police and the FBI? And should we be worried about some or all of this? In this compelling book, Sheldon Krimsky provides clear, informative, and nuanced answers to all these questions and more.'

Naomi Oreskes - Henry Charles Lea Professor of the History of Science and Affiliated Professor of Earth and Planetary Sciences, Harvard University

'Understanding DNA Ancestry introduces readers to the vast panoply of complications that can face those who are interested in the sources of their ancestors. Such readers may be surprised that results from different genetic ancestry companies can vary in their conclusions about the results. Test-takers may sometimes confront unexpected surprises that they had never known about co-existing family members, or discover that an assumed relationship may not be genetically based. They will also learn that some ancestry companies help the FBI in identifying criminals using those companies’ DNA sequencing collections. Furthermore, eager readers may realize that they are learning more than they knew about genetics. Entering these new studies raises questions about whether supposed classical races of peoples have a genetic basis at all. Professor Krimsky has a long career in preparing detailed collections that have been important to science.'

Jonathan Beckwith - Professor Emeritus, Harvard Medical School, Department of Microbiology (and a geneticist)

'In the last three years, there has been a sharp surge in genetic ancestry testing, not only in the US, but across the globe. There are now more than seventy companies promoting an array of such offerings, which range from recreational to medical to forensic uses and claims. Sheldon Krimsky has provided an illuminating social history of these developments, with lucid prose that explains the uses and limits of such testing. But caveat emptor: many consumers will be dismayed to learn that the seductive lure and broad claims commonly outstrip the capacity of these tests to provide clear and replicable results.'

Troy Duster - Chancellor's Professor Emeritus, University of California, Berkeley

'Sheldon Krimsky has written an illuminating description in amazingly simple language on a most difficult but essential subject - ancestry. Krimsky’s explanations of how DNA ancestry works and what it means for modern society are essential contributions to how we, as humans, understand our own variation. Understanding these important aspects of our variation is critical to our worldview and the place of our species in the modern world.'

Robert DeSalle - American Museum of Natural History, New York

‘I do wish more of the people who purchase these tests understood the assumptions and limitations of the technique, perhaps through reading books like this.’

Helge Moulding Source: NetGalley

‘… a well-researched book on the industry of ancestry analysis, as well as exploring how ancestry analysis data can be used beyond constructing family trees … I recommend Understanding DNA Ancestry …’

Allyson Dyar Source: Goodreads

‘The book is interesting for philosophers of science and ethicists, but also for geneticists and the general public who want to know more about the practice of ancestry testing and what they can learn from such tests. I would also recommend it to anyone interested in questions surrounding race and its relation to biology.’

Kristien Hens Source: Metascience