>>8669410>higher gravity planets causing people born on them to be shorterThat's not typically how things work. Environmental conditions don't cause mutations to appear, they just act as a screen for determining if certain mutations that already exist in the population will become ubiquitous. That ubiquity is determined by whether or not individuals with the trait reproduce more than those that don't, and increase the prevalence of that trait in the next generation. Humans are weird because we have mechanisms to extend life for all but the most severe genetic conditions. There are examples of natural selection in humans, but they mostly involve things that we can't control, like disease resilience and traits that make women more likely to miscarry.
If anything the miscarriage part might make the most sense for the high gravity thing, since that provides a clear differential selective pressure that's mostly out of our medical control.
