AFAIK it all boils down to the fact that during embryonal development our cells, which at that point were just a blob of undifferentiated autonomous chemical machines, somehow managed to unanimously agree upon the cardinal directions (up-down, left-right, front-back) for future development - and thanks to this, we don’t have toes growing out of our ears.
Gravity is what makes this happen. Guess what probably is a concern in space?
You know that we’ve gestated various animals in weightless conditions on the ISS, yes? They look normal.
We have? Do you have a source for that? That would be amazing. :)
Toe ears?