At least, I assume so. The more science that backs up whatever is convenient for the purposes of telling a great science fiction, the better. That's why I love books such as "The Physics of Star Trek" by Lawrence Krauss, and "The Science Of Star Wars" by Jeanne Cavelos.
A couple of weeks ago, I blogged about the interesting scientific assertion that genitalia (at least in beetles) evolve much more quickly than other parts. Apparently, it's a matter of what intrigues and pleases the female of the species.
It seems that blood and lungs and genes and DNA evolve in humans. That's a matter of survival in a harsh environment. Of course, we've heard about blood doping, and the suggestion that training at high altitudes can give endurance athletes a competitive advantage.
Aliens from harsher environments than ours could plausibly be considered supermen. If their gravity were heavier (as with my Great Djinn from Tigron) they could leap higher and further. If their air were thinner, they'd seem far more athletic in our rich air.
One has to remember the obverse of this. If these aliens are going to take a human wife home with them, she is going to have problems with their thin air and heavy gravity (as my Djinni-vera does in "Forced Mate".)
Another bit of useful trivia is the effect of weightlessness (space travel) on the human body. For instance, bones lose mass, everywhere except the skull, and some of that unnecessary calcium finds its way to the kidneys where it creates "stones". The Johnson space center in Houston has an astounding display of astronaut kidney stones.
For that reason, gymnasium scenes about spaceships make a lot of sense... and I do have a few of those. Exercise is very important if your alien or human interstellar traveler is going to stay in shape, and reasonably comfortable in the bathroom.
I'll just point out a couple of interesting features of the study of Himalayan Tibetans as reported by Susanna Baird. The Tibetans live almost 3 miles about sea level, but are otherwise closely related to the Han Chinese who live nearby as the crow flies (probably not a crow!) but 3 miles lower.
Time scale. This rapid evolution (of more than 30 genes) is estimated to have taken "the evolutionarily brief span of 2,750 years."
If one has a premise that ones aliens are forgotten human colonists, they'd have had to have left Earth at least in 750 BC. (Or over 100 generations ago.)