In alien environments, some have suggested that the greater the genetic differences the less chance we would be at risk. Is this true? [I‘ve never looked into this idea.]I agree that mass migration to other bodies is not viable (can’t just float a wind-powered vessel across the ocean), the other problem is that if we manage to go to a body that has even primitive life, that life may be very toxic to us by either the minerals they store within themselves, or by epidemics/pandemics and so forth. We have problems with disease here, let alone finding a whole new reservoir of them elsewhere for which we’ll have no way to battle. Shades of the Andromeda Strain.
What happens if we land on a body populated with left-handed proteins? A veritable planet of mad-cow disease?