Why does survival of the fillest not
mean that the strongest or biggest
survive? Can you think of examples
where not being strong and big is an
advantage?

Survival of the Fittest means that animals best suited to a certain area will survive, not that the largest will survive. An example of this is the mouse.

Explanation:

When an animal adapts to live longer, they are adapting to their predators and their environment. For smaller animals, like mice, being big might mean that hawks are able to find them easier, leaving only the small mice to reproduce. I hope this helps!