Significant changes in methods. Please read.

All setters methods were removed. Changes to the field variables can only be made via HARD changes, that take place in specific animals or plant methods (such as tree(), grass(), deer(), etc.).
Also, all methods but the getters and getRandomCode()have been encapsulated. No one but GenePool needs access the the other methods. In fact, GenePool should only be accessed in the Ecosystem's initialization.