Scharf: Dispersal refers to the idea of life spreading far, far beyond its point of origin. It's the same kind of process that we see play out on the Earth where a species migrates to some new environment and then undergoes changes. A single species becomes many species because its descendants necessarily adapt to environments that they find themselves in. The sheer scale of the landscape in which a spacefaring species will find itself must change it. It will cause it to speciate. It will cause it to become maybe multiple species.