Animals cooperate with each other in order to increase their own fitness.

However, there is also some evidence that alarm calls can increase individual fitness as well.

A gene may increase fitness in some habitats, but not others.

Thus, paying into their care will increase the dominant male's overall fitness in the future.

However, the underlying principle is always to increase their overall fitness.

At least 95 percent, she added, increase fitness, flexibility and endurance.

And many people who want to increase their fitness crave a general formula.

Purpose: To help students see the value of regular, sustained exercise in increasing their physical fitness.

These relationships suggest that males do so in order to indirectly increase their own fitness.