So, how possible are plastic bones? Take clorox by Stephen L. Gullet for example, organisms use chlorine as a defense mechanism, which eventually accumulated in the atmosphere (1%),which caused plants to be made out of PVC. If I were to take this to a next level and made creatures have plastic bones, what kind of chlorine concentration would I need? Is it even possible? And what plastic would their bones be made out of?
Real human bones are made of polymers, that's plastic.
Actually most living tissue on this planet is either metallic based or a type of biological plastic
Even the fat under your skin is a polymer, so is your salive and...similar liquids
There's more metal and plastic in your head when compared to the average portable computer.