BOOK REVIEW: DNA USA: A Genetic Portrait of America by Bryan Sykes

A human geneticist has dipped his DNA testing kit into the great melting pot, exploring the genetic history, genealogy and anthropology of Americans. Sykes travels across the country meeting ordinary people and creating portraits of their chromosomes that reflect from whence their ancestors hailed. All the volunteers are given pseudonyms drawn from Hollywood movies, but the stories of their heritage are engagingly real.

As the author of The Seven Daughters of Eve and other books, Sykes is an old hand at writing about genetics for the general public. His experience shows as he deftly introduces highly technical information in reader-friendly ways.

He spends most of the first third of this new book on the ancestry of various immigrant groups, telling their tales through DNA found in mitochondria and on the Y chromosome. Mitochondrial DNA is passed from mother to child, and Y chromosomes trace paternal lines. Sykes has studied human history extensively through these two genetic lenses. Consequently, he focuses there and doesn’t tackle recent genetic tests that sample all of a person’s DNA until Chapter 11.

During his journey, Sykes encounters people who embrace DNA testing as a way to clear up messy genealogical records. He also meets skeptics, who see the technology as a way to discredit their cultural heritage. Sykes doesn’t shy away from these criticisms, presenting a well-balanced view of the disparate attitudes.

W.W. Norton & Co., 2012, 369 p., $27.95