Well, at the genetic level, we are already merging
Which is largely irrelevant, given that humans are not that diverse genetically (but are very good at spotting small differences that they then see as significant in some way or other).
Culturally, we can make our presence felt across the world through media and internet, and we can absorb other cultures through it as well.
But only to those who want to, or happen to, listen. And while I think it is a real boon that people around the world can find common interests -- as on here and any number of interest-specific websites -- it also brings with it a danger -- not a new one, but one which will be seen in more varied guises -- the danger that "cultures" will interact badly (perhaps, eventually, violently with each other).
In the very-much-not Good Old Days, it could be hard being a visible minority in a society, identified by physical appearance (now called 'race'), religion, gender, sexual orientation or, even, occupation. (In some places, this past is still with us.) In a xenophobic or bigoted society, it was obviously disadvantageous, to put it mildly, to respectively look different to the "norm", to worship (or not) in a different way, etc., to the neighbours. But the "good" (on the basis of "there's a hint of water in that glass" optimism) side of this was that in most places, this both only affected relatively small numbers of people and that, because of this, could be policed (though often it wasn't).
Look to today and the forthcoming future, particularly in societies that take little notice (until they suddenly do, or are suddenly encouraged to do) of their neighbours. In normal times, the vast majority of people probably don't care what their neighbours look like, which is good in itself, and have no idea what is going on inside their neighbours' heads. They may not know or (more likely) care that some of their neighbours have common interests -- i.e. some sort of cultural connection -- with people of the same mind around the country, around the world.
This is, of course, fine in 99.999% (or more) of cases: it matters not that one person likes reading SFF while their neighbours' interests include sport, gardening, walking, meditating, watching the TV, cooking, etc. They
may notice -- or not -- if a neighbour is a fervent advocate of a political or religious idea, and may notice more if a neighbour gets loud or violent after consuming too much alcohol (which they do "far too often!").
But as we have seen, our current connected world brings together people with altogether less pleasant interests, often within the privacy of their own homes. Sometimes, though not always, these interests can "easily" (or falsely) be associated with other markers (such as fervency of expressed political and religious views). However, sometimes the interests burst into view from, "apparently", nowhere: even those who know of the general direction someone's thoughts may be taking usually assume that it will go no further than being a loud bore on their chosen subject, not into violent, perhaps deadly, action.
Of course, "the authorities" may know about
some of this, by trying to monitor sites and channels which encourage movement towards the more violent expressions of belief (of whatever kind). But I, as a member of the general public -- and you and others like us -- have no idea. Which may be just as well, because we aren't looking around us wondering who might want to harm us.
But imagine the situation changes. It doesn't matter how -- more atrocities, or the success of rabble-rousers, or something else entirely -- but the situation, the "environment", alters; subtly at first, but then gains momentum. We become suspicious of each other, particularly of those we don't know well (which will be just about everyone else). We can't identify those of whom we are, essentially, afraid. They don't, as they might have done in the past (where such suspicions have led to sometimes great and terrible effect), look different or have a different declared faith to ours; "they" -- They, THEY -- could be anyone.
Now tell me that this is an improvement on what most of us currently experience.
Note that I am not wearing a tinfoil hat: I am deliberately painting a very dark future, one that I hope and expect will not become ours. I just don't want people to have the false idea that the future -- the real one, not as seen in dystopian fiction -- is bound to always be an improvement on our past and present.
) but this seems (anecdotally, I know) to be borne out by the rather large number of good-looking female actors and the like who are obviously a genetic mix. Good examples might be Nicole Scherzinger and Halle Berry. (Just my opinion, natch!)
