摘要:Variation is the spice of life.
In humans, plants, and
animals, genetic variation
within species is immense.
This variation, or genetic diversity,
is a result of different mixes of genes
and is fundamental to the adaptation
and survival of species. When the
environment of a species changes¡ª
because of the occurrence of a new
disease or fluctuations in rainfall
patterns, for example¡ªthe small gene
variations occurring in a population
are essential for its adaptation. The
more diverse the population, the more
likely that individuals will exist that
can cope with a changed environment
or withstand a new pest or disease.