A. World Population Growth: see text figs [human population* & exponential model* &  sigmoid-curves*]
               Unlimited population growth (exponential growth) assumes unlimited resources (?)
               zero population growth occurs when per capita birth rate = death rate
               carrying capacity is the maximum population size that a particular environment can support.

    EARTH...   what is its carrying capacity?     and      how will it be achieved?

     population projection rates?     &  U.N. World Projection figures  &    U.S. Census data tables*
                             Country Projections*               &    Industrial vs. Non-industrial

      Replacement Level Fertility -                     World Replacement Level Fertility (1996)
           a definition...
  *                     U.S. Fertility 1900 to 2000*      population #'s based on RLF's
                                                                         Fertility & Contraception (2000)
*  a look at U.S. fertility 1940-2005
      Population Pyramids -                               
a definition...
Age Structure Diagrams*
World population pyramids
Individual country pyramids
transformation with a DNA vector
      Quick population estimates                        The U.N. Population Database
      World Population Clock site
      U.S. Population Clock site
                        Campbell Concept Activity: Age Structure Pyramids*
      Unique World Population Facts