TAXONOMY: Discipline of classifying organisms and giving them universally accepted names
British buzzard (hawk)
American buzzard (vulture)
○ 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
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