What if part of what makes us human comes from an ancient virus? In this episode, we explore groundbreaking research revealing how retroviral DNA—once thought to be genetic junk—played a critical role in the evolution of myelin. Myelin, the protective sheath around nerve fibers, supercharged the speed of nerve signals and made complex vertebrate brains possible. Scientists have now discovered a specific genetic element, called RetroMyelin, embedded in our DNA by a virus hundreds of millions of years ago.

This viral legacy appears not only in humans but across species—from fish to mammals—suggesting it was a pivotal evolutionary leap. Without this ancient genetic hitchhiker, the rapid, efficient brain communication we take for granted might never have evolved.

Join us as we break down what myelin is, how this discovery reshapes our understanding of brain evolution, and why viruses might be more deeply woven into the story of life than we ever imagined. Whether you’re into neuroscience, genetics, or just love a good twist in the history of evolution, this episode delivers a mind-expanding journey through time, science, and the surprising ways the past still lives inside us.