Taxonomy and Classification

Keeping track of species

• Taxonomy: describing and naming an organism.

• Over 1.75 million species have been named and it is estimated that there are between 4 to 100 million on the Earth.

• Taxonomy is not new, cultures have been naming plants and animals around them for 1000’s of years.

“Watch out—there’s a bear behind that rockOR

“Watch out--there is a large, furry, four-legged creature with long claws, plantigrade locomotion, a big mouth set in a short, stout muzzle, attached to a round head containing small eyes and short triangular ears behind that rock!”

Q. What is the largest wild felid (cat) in the United States?

Mountain LionCougarPanther

Leon ColoradoPuma

Catamount

Answer: All of the above

Puma concolor (Linneaus 1771)

Latin name means: Cat of uniform color

Binomial Nomenclature

Standard system for naming things, using two names. Called a scientific name or Latin name

Carolus Linnaeus described and named over 7,700 animals and over 4,400 plants using Latin names in his book Systema Naturae.

Scientific name does not replace, but instead further defines common name.

Early naming of species1st word was a noun: Genus (capital

letter)

2nd word was an adjective: species (lowercase)

Genus + species = scientific name of an organism.

Always italicize or underline each word separately!!

Procyon lotor– Pro = early– Cyon = dog– Lotor = washing

Spermophilus tridecemlineatus– Sperm = seed– Philus = loving– Tridecem = 13– Lineatus = line

May tell you where it was first discovered:– Didelphis virginiana “2 wombs from Virginia”– Sylvilagus floridanus “wood-hare of Florida”

Or who discovered it:– Lepus townsendii “hare” discovered by “Townsend”

Scientists with a sense of humor

• Aha (a wasp), • Batman (a fish), • Ochisme (a kissing bug),

• Oops (an arachnid),

• Iyaiyai (a fossil fly),

• Sayonara (a fish),

• Stupidogobius (a fish),

• Agra sasquatch ( a carabid beetle with big feet)

• Heerz lukenatcha (braconid)

• La cucuracha (a moth)

• Pison eu (a stinging wasp)

• Polemistus chewbacca (Guess who this is named after?)

• Reissa roni (a microbomboid fly)

Shortcuts

• Shortened genus name very common, ex: E. coli

• Shortened species refers to several species,

ex: Lactobacillus sp.,

Australopithecus sp.

Taxonomic hierarchy

Kingdom Phylum

ClassOrder

Family Genus Species

(sometimes two species names)

How do I remember that?Use a Mnemonic memory device.

• Kingdom

• Phylum

• Class

• Order

• Family

• Genus

• Species

• Kings

• Play

• Chess

• On

• Fine

• Gold

• Sets

Or•Kids•Prefer•Cheese •Over •Fried •Green •Spinach

For example...Human taxonomy

• Kingdom Animalia: multi-celled, no cell wall, heterotrophic

• Phylum Chordata: notochord, spine

• Class Mammalia: warm-blooded, nurse young, no feathers

• Order Primata: five fingers, thumb, collarbone

• Family Hominidae: no tail, bipedal, s-shaped spine

• Genus Homo: not Australopithecus (Man, alike).• Species sapiens: not erectus or habilis (wise,

knowing)

Homo sapien sapien: modern man

Taxonomic goals

Place organisms into logical categories – system must be capable of being used for

information retrieval, so anyone in the world can properly identify any organism.

Place organisms into categories that show ancestor-descendant relationships, also called phylogeny.

Evolutionary Trees • Biologists use the work

of taxonomists to create trees of life based on the evolutionary relationships of the animals.

• Also called cladograms, there are several different types.

18

First prokaryotes 3.75 billion years ago

Single-celled eukaryotes2 billion years ago

Similarities Used to Group Organisms

Cladograms

Taxonomy is evolving

• New discoveries in genetics are leading to changes in the classification of organisms.

• Connections are being discovered and differences are becoming more apparent.

New direction for taxonomists…