Those who know the land depend on certain constants. One
constant we all recognize is that nature is cyclic. The sun
comes up in the east and goes down in the west. Seasons come and
go in the same order every year and this progression brings with
it certain weather patterns.  Animals and plants behave
accordingly. There is a time to be born and a time to die -
times of activity and times of rest - lean times and times of
plenty.  Vegetative succession - from old fields to shrubs to
forest, for example - repeats itself every time a fire or
tornado occurs. And once a cycle is complete, it starts over
again.  Another constant is that while all these cycles
constantly repeat themselves, some changes are occurring that
seldom or never do - at least not for thousands or millions of
years. For example, we are not likely to ever see dinosaurs
again. The passenger pigeon, once more abundant than blackbirds
are today, probably won't be back either. Human influence causes
some of these changes, but not others.  In recen