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diagram rendered with 1-D Chaos Explorer The simple logistic
equation is a formula for approximating the evolution of an
animal population over time. Many animal species are fertile
only for a brief period during the year and the young are born
in a particular season so that by the time they are ready to eat
solid food it will be plentiful. For this reason, the system
might be better described by a discrete difference equation than
a continuous differential equation. Since not every existing
animal will reproduce (a portion of them are male after all),
not every female will be fertile, not every conception will be
successful, and not every pregnancy will be successfully carried
to term; the population increase will be some fraction of the
present population. Therefore, if "An" is the number of animals
this year and "An+1" is the number next year, then An+1 = rAn
where "r" is the growt