Andrew wonders how long habitat will remain for our beloved mollusks and it
is good that we worry.  But all is not lost.  I am beginning to pick up
signals from demographers that counter this pessimism.  Recently I
encoutered the statement that the human population will never again double.
All human populations are aging and birth rates have fallen alarmingly.  The
US rate is now 1.98, well below the 2.1 need to maintain population size and
the same is basically true for Europe.  Asian and African rates are falling
and death rates from HIV are serious problems.  Long term population may be
headed down!