CLASSIFICATIONChapter 14

Finding Order in Diversity

TAXONOMY•Discipline of

classifying organisms & give each a name

WHY CLASSIFY?

1. To name organisms 2. To group them in a logical

way

WHY CLASSIFY?

3. Classification makes life easier.

CLASSIFICATION

• Organisms are put into groups that have biological significance

SCIENTIFIC NAMES

1. Give Biologists a way to communicate

2. Many organisms may have several names. Ex: Cougar: mountain lion, puma or catamount.

Photo courtesy Texas Parks and Wildlife Department © 2004

Felis concolor

BINOMIAL NOMENCLATURE

• Developed by Carl Linnaeus– Swedish botanist

• Two-name naming system

BINOMIAL NOMENCLATURE

• First name: Genus– first letter is capitalized– italics or underlined

– Share important characteristics

Homo sapien

Ursus arctos

Grizzly bear picture is reproduced with permission from WWF. © 2004 WWF- World Wide Fund For Nature (Formerly World Wildlife Fund). All Rights Reserved. www.panda.org.

• Second name: species– first letter is lower-case – Italics or underlined

– One particular kind of organism

Homo sapien

Ursus arctos

BINOMIAL NOMENCLATURE

LEVELS OF CLASSIFICATIONDomain

KingdomPhylumClassOrderFamilyGenus

Species

LEVELS OF CLASSIFICATION

• Domain– largest & most inclusive

• Species – smallest & most specific

CLASSIFICATION & RELATIONSHIPS

• The more shared levels, the more related

What do the scientific names of the polar, grizzly & panda bears tell you about their similarity to each other?

Ursus maritimus

Ursus arctos

Ailuropoda melanoleuca

Pictures reproduced with permission from WWF. © 2004 WWF- World Wide Fund For Nature (Formerly World Wildlife Fund). All Rights Reserved. www.panda.org.

Organism Cat Wolf Fly

Kingdom Animalia Animalia Animalia

Phylum Chordata Chordata Arthropoda

Class Mammalia Mammalia Insecta

Order Carnivora Carnivora Diptera

Family Felidae Canidae Muscidae

Genus Felis Canis Musca

Species F. domesticus

C. lupus M. domestica

EVOLUTIONARY CLASSIFICATION

• Organisms are grouped into categories that represent relationships

• Phylogeny (Evolutionary Tree): Evolutionary relationships among organisms.

Not all features are inherited from a common ancestor

• Convergent evolution: Similarities evolve in organisms not closely related

• Due to living in similar habitats

• Ex: Wings of a bird and insect

CLADOGRAM

A B C D E F

Speciation: formation of two new species from one

Clade or lineage

TIME

CLADOGRAM: Vertebrates

Fur & MammaryGlands

Jaws

Lungs

Claws or Nails

Feathers

HagfishFish

FrogLizard

Pigeon

MouseChimp

Derived characteristic: Evolved in one group but not another

Matching:MammalsAnimals with backbonesInsectsAll animals

A.

B.

C. D.

C

BD

A