In the hunt for antimatter galaxies, the tools that we are currently using look for gamma rays that would be emitted due to annihilation events, because everything else about these galaxies is predicted to be the same emission-wise. The hypothesis is that these annihilation events would occur along matter-antimatter boundaries. However, why would we even assume that these boundaries exist? If there are entire galaxies composed of antimatter, how do we know that there would be these events at all? It could be true that these galaxies exist in virtual isolation from matter due to the vast distances between galaxies. Furthermore, the very same annihilation events should theoretically occur in a mostly matter galaxies. For example, there are large clouds of antimatter within our own galaxy. Would not the number of annihilation events in a galaxy that were say 90% matter and 10% antimatter be *exactly* the same as in a galaxy that is 90% antimatter and 10% matter? Wouldn't there be no difference in the emitted gamma rays?