What is an example of the struggle for existence?

An example of the struggle for existence can be observed in a predator-prey relationship, such as that between wolves and deer. Wolves rely on hunting deer for food, while deer must evade wolves to survive and reproduce. This competition drives both species to adapt their behaviors and physical traits; for instance, faster deer may escape more effectively, while wolves may develop better hunting strategies. This ongoing interaction highlights the natural selection process and the constant struggle for survival in ecosystems.