In a game system one must wonder why bother to have rules to for reproduction and a lifespan. In truth, it is not needed. Unless you intend on creating a world with a dynamic population of species. A world that once the last of a species has been killed they are then extinct.
But population plays a bigger role in the real world than people give it credit. A population that grows to quickly can face issues of starvation, disease and the overuse of resources like water supplies. A population the does not grow quickly enough can be outpaced by their competitors. These issues can lead to war or even crime.
Dragons, the canon of fantasy rpgs, are often the target of adventures for the fame and fortune contained withing their lair. But what if this was the last dragon? Using the classic western dragon archetype, that being a powerful force of destruction, do you still seek the end of an entire species?
I'm not trying make a moral point. I am trying to raise the questions of the role that a population plays in the greater scheme of life and to this end I feel the need to justify the existence of a creature in the Red Ash World Engine.
As a game mechanic Red Ash will use life span and its stages of life, plus the rules for reproduction to determine the population points that a species has during the creation processes and the pace that a population can grow. Implementing these new rules will require me to remake the defined species and this will take some time.