Coevolution
Like parallel evolution, sometimes there is a need to develop similar traits for survival. Other times, the need to evolve comes directly as a result of the species you’re evolving alongside. This happens with predator and prey as well as host and parasite pairings in nature. Think of the Turtle for example.
It is clear that if you look at this slow-moving creature, it’s not much of a threat to anyone. If left unattended, the turtle will die easily in nature. Yet the turtle’s ancestors seemed to realize this, which is where the shell came from. Now, the turtle can keep a lot of its problematic issues while also remaining protected by its shell.