The phrase "survival of the fittest" describes a central idea in the theory of evolution, but it slightly simplifies reality. Here are some main points that explain why the strong survive in nature:

1. Adaptation and adjustment to the environment:
The most successful animals are those that are able to adapt to changes in their environment. This includes developing physical traits or behaviors that help them survive, such as speed, resilience or intelligence.
2. Competition for resources:
In nature there is competition for resources such as food, water and shelter. An animal that is stronger or more skilled in competition can survive and thrive in harsh conditions.
3. Urge to procreate:
Animals that manage to survive are also likely to reproduce, ensuring future generations of their beneficial traits.

4. Living in groups:
Sometimes the strong survive not only thanks to their personal strength but also thanks to living in groups. Animals like wolves or dolphins use group work to hunt and protect themselves.
5. Protection from predators:
Strong or agile animals can avoid or fight predators, increasing their chances of survival.
6. Health and heredity:
The strong tend to be healthier, which allows them to survive harsh conditions and live longer.
7. Learning opportunities and transfer of knowledge:
Smart animals manage to develop new techniques and skills, which increases their chances of survival.

Summary:
Therefore, the importance is not only in physical strength but also in the ability to adapt, be smart, work in groups, and utilize the existing resources. The strong survive not only because of their strength, but also because of other qualities that help them survive in the changing environment.