This is absolutely
the book to read if you're interested in genetic history, either your own or humanity's. Reich zooms out tens and hundreds of thousands of years ago, far past most Big History books, discussing how the latest research on recent discoveries of ancient DNA has begun to make sense of the vast movements of peoples in the dim unremembered mists of time from before we have written records. The rapid pace of technological advancement in genetics research, to the point where we can reconstruct detailed models of peoples we know only from scattered bone fragments, is challenging a lot of what we thought we knew about the past (did humans really evolve solely in Africa? how many waves of migration from Asia to the Americas? how recently did modern racial categories form?), and as astonishing as it is to imagine that we can track the migration and reproductive patterns of long-vanished ethnicities and even extinct subspecies like Neanderthals and Denisovans, genetics has advanced to the point where we can even identify "ghost populations" in our modern genomes - long-dead ancestors who have left no trace of language, settlement, or literature, but whose migrations and mixings live on in our DNA. The rapid pace of discovery in this field means many specific conclusions might be in flux, but as Reich shows, the wealth of knowledge unlocked by DNA sequencing means fields like history and anthropology already have plenty to chew on. I haven't found this kind of rigorous, sustained investigation of the deep roots of our ancestry anywhere else.
