TAXONOMYFinding Order in Diversity

TAXONOMY: Discipline of classifying organisms and giving them universally accepted names

British buzzard (hawk)

American buzzard (vulture)

WHY CLASSIFY? To name organisms and to group them in a logical manner

HOW TO CLASSIFY?

○ Usually by structure and appearance

○ Phylogeny and habitat can be factors

○ Using common names is confusing because many organisms have several different common names ● Cougar AKA mountain lion, puma,

catamount○ Scientific names eliminate confusion

● Cougar AKA Felis concolor

Assigning Scientific Names

○ Carolus Linnaeus was a Swedish botanist ○ He developed binomial nomanclature ○ Binomial Nomenclature: A two word naming

system

Carolus Linnaeus

○ The first part of the scientific name is the genus

○ The second part of the scientific name is the species

○ Genus is capitalized, species is not

○ Both words are italicized or underlined

Assigning Scientific Names

Homo sapien

Canis lupus

Gnathia marleyi

Assigning Scientific Names

Aptostichus stephencolberti

Aptostichus barackobamai

Aptostichus angelinajolieae

Aleiodes shakirae

Litarachna lopezae

Aegrotocatellus jaggeri

Aleiodes falloni

DOMAINKINGDOMPHYLUM

CLASSORDERFAMILYGENUSSPECIES

CATEGORIES OF CLASSIFICATIONMost Broad

Most Specific

The more taxonomic levels that two organisms share, the more closely related they are

CATEGORIES OF CLASSIFICATION

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

THINKING CRITICALLY

QUESTIONS

What type of animal is Musca domestica? a. Flyb. Catc. Wolf

QUESTIONS

Which two organisms are most closely related?

a. Fly and catb. Fly and wolfc. Cat and wolf

QUESTIONS

At which classification level does the evolutionary relationship between cats and wolves diverge?

a. Kingdomb. Familyc. Phylum

Ursus maritimus

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

Ailuropoda melanoleuca

What if you don’t know what an organism is?

○ One way to identify an unknown organism is to use a dichotomous key

○ Dichotomous key: an identification tool that uses pairs of contrasting descriptions

○ Each description will either identify an object or send you to another pair of descriptions

DICHOTOMOUS KEYS

Before you use a key: ○ Look over all the traits of your organism○ Identify key features and terms○ Try to narrow down what you’re looking at○ Always start your search for the correct

scientific name at the beginning of the key

DICHOTOMOUS KEYS

1. a. If it runs on gas Go to 2b. If it doesn’t run on gas Walking

2. a. If it is on land Go to 3b. If it’s not on land Boat

3. a. If it has four wheels Car b. If it has two wheels Motorcycle