Most  populations  tend  to
   overproduce  offspring,  but  due  to  limited  resources, individuals
   struggle  for  existence  and  populations  remain stable in size over
   time.
<P>
   Members  of  the  population  exhibit  herotable  variation  in  their
   characteristics.
<P>
   Those  individuals  with  heritable  traits  best  suited to the local
   environment will generally produce more offspring - natural selection.
<P>
   Over  the  generations,  heritable  traits  that  enhance survival and
   reproductive   success   tend   to   increase  in  frequency  among  a
   population's individuals. The population adapts to its environment and
   evolves.
<P>
<P>
<P>
<P>
<P>