A compelling portrait of a people thought lost to time…a remarkable account of humanity's quest to rediscover its ancient origins, using modern methods to illuminate the world as it was before the advent of written history. For Ms. Spinney, this distant and obscure past holds lessons for the future, as the preservation and purity of language is increasingly a contemporary concern.

Michael Patrick Brady, Wall Street Journal

Fluid... a global scientific odyssey.

Anjana Ahuja, The Guardian "Best Science and Nature Books of 2025"

Beguiling and revelatory…Spinney is a stylish and erudite writer; it's the rare science book that quotes Keats, Seamus Heaney, and Ismail Kadare. She also has a keen sense of the romance of her subject.

Laura Miller, Slate

An impressive piece of work . . . Rewarding.

Dennis Duncan, Washington Post

Laura Spinney tells engaging tales of archeologists traipsing through fields, linguists working toward professional vindication and many others active in the search for understanding of how these ancient languages traveled, fragmented, warred and traded to eventually became the dominant Indo-European languages today.

Rich Hunt, Scientific American

Proto is a rich and well-researched study of language development across thousands of miles and tens of thousands of years. But most importantly, it shows that we are more connected than we might have been led to believe.

Zuzanna Lachendro, The New Statesman