Interestingly, the only Trek series which ever seem to have dealt with this (even if only on a very basic level) was Voyager.
Many of the Alpha quadrant species have coexisted with each other ever since they were warp capable.
But that would have little, if any, bearing on how life, even sharing some common roots, would vary based upon thousands upon thousands of years of evolutionary modification due to different atmospheric conditions, different suns, different gravities, different planetary rotational rates, etc, etc. The biology doesn't drive the environment, the environment drives the biology.
There's also that TNG episode about a master race seeding planets with their genetic template, which answers why most sentient life in the quadrant was bipedal and breathes oxygen. Doesn't explain why the rest of the galaxy was also bipedal, though.
Yeah, well.. we know the REAL reason that everyone was "just like us," of course... because the series were made for us, and the creature were, by and large played by us.
Still doesn't make it make practical sense, of course.
(Species 8472 was tri-pedal, and Voyager and TNG made numerous mention of species they've interacted with off screen that were quadripeds or other strange body types which would be difficult and expensive to show on screen).
Yeah, and those species would not serve on a starship with human's either.
Which takes us back to the original point... you wouldn't go for "airlocked quarters" for crew with dramatically different life-support requirements, for the simple reason that it would be impractical.
I mean, if given a choice of serving on a ship where you could move around safely and comfortably, or where you couldn't leave your own cabin without the equivalent of a spacesuit (or at least SCUBA gear) on... which would you choose? And where would you be most effective?
And if you were asked to go live on a ship where the lighting was all in dim red with much of the signage in infrared, and this was the case everywhere except for your cabin, 24 hours a day, 7 days a week, 365 days a year... oh, except that the day was only eleven and 3/4 hours long, and the local calendar was broken up into sixteen-day "weeks" and a year was four and a third of our years... and atmospheric temperature was 115 with 100% humidity at all times... and there was a perpetual "background noise" which helped the rest of the crew feel comfortable, but which sounds like fingernails on a blackboard to YOU... would you be happy?