I often think of the many SF stories that assume FTL starships. How sad it would be for our future if the light speed barrier cannot be broken. To reach the nearest stars at sub-light speeds would take many years, and we would likely have to travel much further than the nearest stars to find a habitable planet. To take advantage of time dilation, ships need to expend prodigious amounts of energy to accelerate to high fractions of c. What society would bother to build interstellar ships? Isn’t there a way to spread through the galaxy at near-light speed, and without building space ships? The solution, I think, is to avoid sending people or any object with mass through space. Send only information. Send information about our DNA. We need only to establish contact with a near neighbor species, learn how to communicate, and then transmit instructions for how to grow a human in a test tube. Presumably, the other species would reciprocate, so that we could grow specimens of their species here on Earth. To be sure, the specimens would have no memory or culture from their native worlds, but they would have interesting properties. I’m sure the aliens would be very interested in studying these specimens. We could also send some “I Love Lucy” episodes to teach our expatriate relatives what it is like to be human. Hopefully, the neighbor species would eventually find other near neighbors, and transmit their DNA instructions plus our DNA instructions to them. In that manner, hop by hop, our DNA would spread across the galaxy. How fast might it propagate? C/2 is a believable number. Figure 100,000 years transmit time, plus 100,000 years of those instructions sitting on a shelf waiting for someone to dare execute them. To be sure, creating alien DNA would have risks, and many would deem those risks unacceptable. Yet, given the passage of thousands of years, it is a virtual certainty that someone will be curious enough (or foolish enough) to do it. It might be difficult and expensive for aliens to reproduce the environmental conditions needed for specimens of our species to survive. Therefore, it would be convenient for them to modify our genes to create specimens that aren’t 100% human, but which can survive in the unmodified alien environment. As the DNA instructions get transmitted and retransmitted to more and more places, the genetic engineering would become tedious. Therefore, it would be easier for everybody to use genes capable of surviving in nearly any environment. In other words, they could settle on a galactic standard gene set. I imagine something like the genes of a water bear (Tardigrade), grafted onto the genes that give us intelligence. The result would not quite be a pan-galactic-species but perhaps a pan-galactic-phylum of intelligent species, with each world populated by a mixture of all those species. The whole concept could be viewed as the next phase of evolution. How long might it take to evolve a galactic phylum? Just plucking a number out of the air, let us say 100 galactic transversals at and average speed of c/2, or twenty million years. That is damn fast on the evolutionary scale. The sad part would be the havoc it rains on the heads of science fiction writers. How constraining, if no individual is ever transported to an alien world. How unsatisfying it would be to never having culture clash with culture. Instead having them all semi-independently evolving into a monoculture while never once meeting face to face, and never once launching an interstellar space ship. Considering how hard it is to have a truly new idea in this world, I'm expecting to hear that this subject has been explored before.