The original home of fully three-fourths of our domestic animals was the
continent of Asia, where, also, the first home of man himself is placed.
It seems quite probable that nearly all of these animals were first held
as captives by the early peoples for food supply, and that their other
uses developed later. As the races spread to the continent of Europe and
thence over the habitable world, their animal servants spread with them,
and others were added, adapted to varying climatic and other conditions.
Our own continent--North America--has added only the turkey and the
cochineal insect, while South America has contributed the alpaca, llama,
and guinea-pig. No new domestic animals have been developed during the
last two thousand years; and the natural conclusion is that all must
have come into use at various stages from the very earliest period of
man down to the time of the Christian Era.