hmmm, isaac asimov wrote two trilogies on this subject
The robot series beginning with "Caves of Steel"
and
"Foundation" series.
In both, mankind eventually populated other worlds. But after that occurs, those worlds become independent cultures. Eventually, they won't entertain visitors from Earth because they have wiped out many of our diseases in their worlds where there are far fewer people.
I suspect that if this were possible, the people in those new worlds would become very different from those on this world in a short period of time.
Think of the comparison between America and the old world.
It's possible that after the first ship lands there - if the second or third ships don't arrive within a few decades, they wouldn't be welcome.
Asimov's not the only one to hit that. I don't recall the author, but there was a story where a gal from a colony world got a scholarship to M.I.T., but she had to come up with the entry costs. Her friends did a massive campaign, because the screening, quarantine, and purging routines came to a hundred thousand 'stars' (which I estimated to be about $3 each). It was totally unnecessary, medically, but it was Earth's way of responding to what the established colonies made visitors go through. During the course of the story she trips over a program working on building immunity to every known human disease into the human genome... which is okay, but there's an inside cabal also mixing in "improvements" to the species, like faster reflexes, tougher bones, more durable joints, better eyesight....
In the story it took about five generations before the colonists got hardnosed about Earth visitors and the diseases, which about corresponds to the time it would get to be self-sufficient with its own space capability.
At any rate, there was an argument how far the changes/additions should go before the result would still be human, and a plot arose to steal some of the material when the biotechs were finished, so the colony worlds wouldn't get shut out as a separate species. So I think we're more likely to 'evolve' by tinkering than by standard track.
Of course then are are the tales where the engineering goes further, creating aquamen for watery worlds, "dwarves" for mountain worlds... and "elves" for some forest worlds -- and the argument there is whether they've just gotten aesthetic versus functional, and whether they're dooming the race(s) to future strife.
If they were going to turn me into a dwarf, I wouldn't go -- elf, yes.
