Cixin Liu's The Dark Forest explores this idea, mostly to point out that there is no acceptable method to choose who gets evacuated and who stays behind. The author argues through his characters that any attempt at evacuation would create immediate and violent conflict between humans.
See also Seveneves[1], where a similar evacuation does indeed have some downsides. It's also a theme in one of my favorite Ted Chiang stories, "Mono no Aware"[2].
Seveneves and the Dark Forest series are literally the last two (sets of) books I read and they are so wonderful. The last book in the Dark Forest series in particular has some of the most mind-blowing concepts I've encountered in SciFi.
Conceivable, but not remotely available at the moment, or on the horizon. Not to mention, evacuation to where? The whole solar system would be thrown into disarray, and we don’t know of any Earth-like planets in other systems. We’d be toast, end of story. Maybe in a few hundred years, and given a lot of warning we could save some small fraction of humanity.
Shotgun approach: anywhere we think we might have even a remote hope of colonizing, prioritized and weighted (in terms of number of passengers) by likelihood of success.
It's amusing to think on two such populations of this human diaspora surviving to eventually reunite one day, probably tens of thousands of years after the original colonization event faded from their collective cultural memories.
This is almost the plot to the Killzone franchise: as in, separate populations of human colonists at war with each other, long after they forgot their common ancestry.
> After studying the ambiguous number blocks for hours, the discovery is made that these fragments are compatible DNA strands which have been recovered from different worlds all over the galaxy. The crew eventually believe that they have discovered an embedded genetic pattern that is constant throughout many different species, and it is speculated that this was left by an early race that pre-dates all other known civilizations. This would ultimately explain why so many races are humanoid.
Pretty sure if today's scientists had access to a dozen alien populations, DNA analysis would be one of the first things they set about. I'm not a trekky, but I would think that this should have happened chronologically much earlier in the canon.
>I'm not a trekky, but I would think that this should have happened chronologically much earlier in the canon.
Unfortunately, that was a two-part afterthought and the canon in that respect was never really explored. You could set an entire season or series around it, and Star Trek had a lot of dropped ideas with potential like that.
Where do you want to go if planets are thrown off orbit? You need to plan that years or most likely decades before. We also have no evidence that we are capable of surviving off Earth long term.