Benefits And Costs Of Migrating Species January 19, 2001 Whether
by choice or chance, when humans have gone to new places, other
species new to those lands have often journeyed with them. While
some migrations can impose heavy social costs -- such as the
introduction of new diseases -- the benefits are often enormous.
- The potato traveled from the Andes to Europe, North America
and elsewhere, as did the tomato; soybeans probably reached the
Americas from China; exotic plants and animals have made their
way around the world thanks to collectors; and when Europeans
migrated overseas, they took along wheat, barley, rye, cattle,
pigs, horses, sheep and goats. - Today, introductions of
isolated species to new habitats are occurring with stunning
rapidity -- as global imports of agricultural products and
industrial raw materials have shot from $55 billion in value in
1965 to $480 billion in 1990, according to the World Resources
Institute. - Yet only a tiny proportion of alien species
establish new populations and