Herd of reindeer, Rangifer tarandus,
during annual roundup by Laplanders in
northern Sweden. The
same species is
known as caribou in North America.
Order Artiodactyla, family Cervidae.
Some 10,000 years ago, at the time
people developed agricultural methods,
they also began the domestication
of mammals. Dogs were certainly
among the first to be domesticated,
probably entering voluntarily into their
human dependence. The dog is an
extremely adaptable and genetically
plastic species derived from wolves.
Much less genetically variable and certainly
less social than dogs is the
domestic cat, probably derived from an
African race of wildcat. Wildcats look
like oversized domestic cats and are
still widespread in Africa and Eurasia.
Domestication of cattle, buffaloes,
sheep, and pigs probably came much
later. It is believed the beasts of burden—
horses, camels, oxen, and llamas—
probably were subdued by early
nomadic peoples. Certain domestic
species no longer exist as wild animals,
for example, the one-humped
dromedary camel of North Africa and the llama and alpaca of South America.
All truly domestic animals breed in
captivity and have become totally
dependent on humans; many have
been molded by selective breeding to
yield characteristics that are desirable
for human purposes.
Brown rat, Rattus norvegicus, living all
too successfully beside human
habitations. Brown rats not only
great damage to food stores but also
spread disease, including bubonic plague
carried by infected fleas, that
greatly influenced human history in
medieval Europe), typhus, infectious
jaundice, Salmonella food poisoning, and
rabies. Order Rodentia, family Muridae.
Some mammals hold special positions
as “domestic” animals. The elephant
has never been truly domesticated
because it will seldom breed in
captivity. In Asia, adults are captured
and submit to a life of toil with astonishing
docility. Reindeer of northern
Scandinavia are domesticated only in
the sense that they are “owned” by
nomadic peoples who continue to follow
them in their seasonal migrations
(Figure 30-28). The eland of Africa is
undergoing experimental domestication
in several places. It is placid, gentle,
and immune to native diseases and
produces excellent meat.
Activities of mammals can in some
instances conflict with human activities.
Rodents and rabbits are capable of
inflicting staggering damage to growing
crops and stored food (Figure
30-29). We have provided an inviting
forage for rodents with our agriculture
and convenienced them further by
removing their natural predators.
Rodents also carry various diseases.
Bubonic plague and typhus are carried
by various rodents, including house
rats and prairie dogs. Tularemia (rabbit
fever), is transmitted to humans by the
wood tick carried by rabbits, woodchucks,
muskrats, and other rodents.
Rocky Mountain spotted fever is carried
to humans by ticks from ground
squirrels and dogs; Lyme disease is
transmitted by ticks from white-tailed
deer. Trichina worms and tapeworms
are acquired by humans who eat the
meat of infected hogs, cattle, and other
In the introduction to this section,
we alluded to the discouraging
exploitation of whales as one example
of our inability to reconcile human
needs with preservation of wildlife.
Extermination of a species for commercial
gain is so totally indefensible
that no debate is required. Once a
species is extinct, no amount of scientific
or technical ingenuity will bring it
back. What has taken millions of years
to evolve can be destroyed in a decade
of thoughtless exploitation. Many people
are concerned with the awesome
impact we have on wildlife, and there
is more determination today to reverse
a regrettable trend than ever before. If
given a chance, mammals will usually
make spectacular recoveries from
human depredations, as have the sea
otter and the saiga antelope, both once
in danger of extinction and now