Earlier quoted context omitted.
You cannot, for instance, fire someone for being black. These characteristics are protected in the sense that discrimination against them in certain areas is illegal.
Ok, but then the US Air Force would not hire anyone shorter than 64 inches or taller than 77 inches. Your height is a part of your genetics, you can't change it. Why are people outside of this range not protected? Am I oversimplifying something here?
1. The "Genetic Information Nondiscrimination Act" specifically bans using "Genetic Information" in certain circumstances, which is generally understood to mean e.g. DNA testing. Discriminating on height does not fall into this.
2. You could still fall into issues with e.g. the Civil Rights Act of 1964 by having a height requirement if e.g. far more men than women fall into that height range, however there are exceptions[A] built into that act when a job has specific requirements, one being you can ask for "male models" to model clothing targeted at men.
A: https://en.wikipedia.org/wiki/Bona_fide_occupational_qualifi...