It’s easy to associate the word fitness to a healthy and active lifestyle. In other way, an ecological one, results in Biological Effectiveness a simply balance between an organism’s life (survival) and the number of descendants left (fertility). Varies over time influenced by chance and environmental characteristics. Numerically, according to the weather and the environment, the fitness is measured with a different parameters, more suitable to the situation of the environment, something like to choose the car with the most appropriate features for the type of track that will be driven in (city, circuit, or mountain):
Ro for permanent and stable environments (saturated). Grow to the maximum regardless of the time.
ʎ for permanent but variable environments. Grow to the maximum per unit of time and thought in the long term.
r for ephemeral and unstable environments. Grow to the maximum per unit of time and thought in the short term.