Sykes (Human Genetics/Oxford Univ.; Saxons, Vikings, and Celts: The Genetic Roots of Britain and Ireland, 2006, etc.) combines history, science, travel and memoir in one grand exposition of what it means to be an “American.”
America, writes the author, is “where the genes of three great continents converge.” Initially, it was Asian forebears that peopled the new world. Through analysis of mitochondrial DNA, the origins of Native Americans can be traced to three mother clusters arriving from Siberia and a fourth from Polynesia. The arrival dates, based on mitochondrial DNA mutation rates, establish a range of about 16,000 to 20,000 years ago. Unfortunately, high-handed methods toward Native tribes have created a rift that persists today, for what the scientists were doing was destroying beliefs that these natives have existed here forever. Not so for Americans of European or African descent. They know they came from elsewhere and are eager for all the details, as witness the thriving genealogy industry. Geneticists can use mitochondrial DNA as well as y-chromosome analysis, along with the latest DNA chip technologies, including “chromosomal painting.” The latter allows experts to pinpoint selected blocks of genes on individual chromosomes that reflect a European, Asian or African ancestor. Traveling cross-country by train and car with his son and back again with a female assistant, Sykes gathered saliva samples for painting analysis. In a graceful text, the author delivers rich images of the American landscape, conversations with strangers, and historic asides on the waves of immigration, the Indian diasporas and the various federal laws that shaped the movements of people across the continent. In the end, Sykes provides the revelations of those salivary analyses: For the most part we are a motley crew, so much so as to give the lie to any idea that there are pure races or ethnicities.
For that reason alone, the book should be celebrated. But Sykes should also be applauded for his skills as a storyteller, science expositor, travel companion and compassionate human being.