Evolution—The Theory and Its Supporting Evidence - The Changing Earth: Exploring Geology and Evolution - page 482

TABLE 18.2 Expanded Linnaen Classifi cation Scheme (the animal classifi ed in this example is the coyote, Canis latrans )
Kingdom Animalia—Multicelled organisms, cells with nucleus (see Chapter 19); reproduce sexually; ingest preformed organic
molecules for nutrients
Phylum Chordata—Possess notochord, gill slits, dorsal hollow nerve cord at some time during life cycle (see Chapter 21)
Subphylum Vertebrata—Those chordates with a segmented vertebral column (see Chapter 21)
Class Mammalia—Warm-blooded vertebrates with hair or fur and mammary glands (see Chapter 22)
Order Carnivora—Mammals with teeth specialized for a diet of meat (see Chapter 23)
Family Canidae—The doglike carnivores (excludes hyenas, which are more closely related to cats)
Genus Canis —Made up only of closely related species—coyotes and wolves (also includes domestic dogs)

Species Iatrans —Consists of similar individuals that in nature can interbreed and produce fertile offspring

Classifi cation—A Nested Pattern
of Similarities
Carolus Linnaeus (1707-1778) proposed a classifi cation sys-
tem in which organisms are given a two-part genus and spe-
cies name; the coyote, for instance, is Canis latrans. Table 18.2
shows Linnaeus's classifi cation, which is a hierarchy of catego-
ries that becomes more inclusive as one proceeds up the list.
The coyote ( Canis latrans ) and the wolf ( Canis lupus ) share

numerous characteristics, so they are members of the same
genus, whereas both share some, but fewer, characteristics
with the red fox ( Vulpes fulva ), and all three are members of
the family Canidae (

Figure 18.13). All canids share some
characteristics with cats, bears, and weasels and are grouped
together in the order Carnivora, which is one of 18 living
orders of the class Mammalia, all of whom are warm-blooded,
possess fur or hair, and have mammary glands.

◗

Subphylum - Vertebrata

Class - Mammalia

Order - Carnivora

Family - Canidae

C. lupis

C. latrans

Coyote Wolf

Genus - Canis latrans

Vulpes vulpes

C. lupis

Coyote

Species - latrans

Red fox

Wolf

Coyote

◗ Figure 18.13 Classifi cation of Organisms Based on Shared Characteristics All members of the
subphylum Vertebrata—fi shes, amphibians, reptiles, birds, and mammals—have a segmented
vertebral column. Subphyla belong to more inclusive phyla (singular, phylum ), and these in turn belong
to kingdoms (see Table 18.2). Among vertebrates, only warm-blooded animals with hair or fur and
mammary glands are mammals. Eighteen orders of mammals exist, including the order Carnivora
shown here. The family Canidae includes only doglike carnivores, and the genus Canis includes only
closely related species. The coyote, Canis latrans , stands alone as a species.