Classification and Taxonomy Classifying Organisms Taxonomy the science

Classification and Taxonomy

Classifying Organisms • Taxonomy: the science of describing, naming, and classifying organisms

Ways to Classify Organisms • • Unicellular vs. multicellular Prokaryote vs. eukaryote Autotroph vs. heterotroph Linnean system and binomial nomenclature (today)

Old Systems of Classification • Aristotle (Greek, 2400 years ago): classified only as plant or animal

…but where does this stuff go?

A better system • Carolus Linnaeus (1707 -1778) • “Father of Taxonomy” • His work is the basis of classification systems used today

Modern Classification • Can classify all life into 3 main domains – Most general/most inclusive category – Bacteria, archaea, eukarya (written in chart)

Characteristics of Domain Bacteria • • • Prokaryote Small Unicellular Have cell wall Example: E. coli

Characteristics of Domain Archaea Prokayote Small Unicellular Have cell wall Live in harsh environments • Example: Pyrococcus abyssi • • • Some of the first Archaea were found in the hot springs of Yellowstone Park

Characteristics of Domain Eukarya • • • Eukaryote Small or large Uni. or multi. Some have cell walls Ex: protists, fungi, plants, animals

Be ready to answer! • How did Aristotle classify organisms? • Who came along and improved Aristotle’s method? • Which domain of life has organisms that live in very harsh environments? • Which domain are humans contained in? • Which 2 domains have prokaryotes?

Domains can be broken into 6 kingdoms

The 6 kingdoms: • Kingdom Eubacteria (“true” bacteria) – Prokayote – Unicellular – Includes autotrophs and heterotrophs

The 6 kingdoms: • Kingdom Archaebacteria (“ancient” bacteria) – Prokayote – Unicellular – Autotrophs (chemosynthesis), heterotophs

The 6 kingdoms: • Kingdom Protista (protists) – Eukaryote – Majority are unicellular – Autotrophs, heterotophs

The 6 kingdoms: • Kingdom Fungi – Eukaryote – Majority are multicellular – Heterotrophs

The 6 kingdoms: • Kingdom Plantae (plants) – Eukaryote – Multicellular – Autotrophs

The 6 kingdoms: • Kingdom Animalia (animals) – Eukaryote – Multicellular – Heterotrophs

“Domain” and “kingdom” are still too broad. We continue to break organisms into more and more specific categories. Same information, just presented in a different way

Classification of Humans Domain: Eukarya Kingdom: Animalia Phylum: Chordata Class: Mammalia Order: Primates Family: Hominidae Genus: Homo Species: Homo sapeins

Guess the organism!

To remember the order: • • Domain Kingdom Phylum Class Order Family Genus Species Dear King Phillip came over for great spaghetti

Classifying organisms • Taxon: any particular group within a taxonomic system – “Taxa” is plural – Examples of taxa: • • Kingdom Phylum Class etc.

In order, the taxa go from general to specific. • • Domain Kingdom Phylum Class Order Family Genus Species General Specific

Same genusvery closely related Species- the most unique

Be ready to answer! • Which kingdom has “true” bacteria? • Which kingdom has organisms like Volvox, a protist? • Which kingdom has mushrooms? • Which kingdom has organisms that are ALL autotrophs? • Which kingdom has “ancient” bacteria? • Which kingdom has ants?

Why do scientists use Latin to classify and name organisms?

HERE’S AN EXAMPLE WHY. What is this?

This organism can be called a: • • Cougar • Mexican lion • • • Mountain lion • • Deer tiger • • Mountain • screamer • Puma • • Florida • panther • • Catamount • • Panther Silver lion Devil cat Indian devil Sneak cat King cat Mountain devil Red tiger Deercat Fire cat Plain lion • • Grey lion Caracajou Klandagi Catawampus Quinquajou Long Tail Swamp lion

Problem! • There at least 50 common names for the cougar. The same issue arises with many other organisms!

Why classify with a scientific name? • Since common names vary, scientific names ensure you’re talking about the correct organism • Some names are misleading (“jellyfish”)

Scientific naming system • Binomial nomenclature- a two-part name system for writing scientific names. Based on Latin.

Rules • Genus name written first – ALWAYS capitalized • Species name is written second – NEVER capitalized – NEVER by itself • Both words are italicized if typed, underlined if handwritten

Find the errors! • Taxidea Taxus • procyon lotor • Delphinidae Delphis

Sidenote with an example: • Cannis vulpes is a fox – Writing C. vulpes is acceptable. – Writing Cannis v. is not. – Writing vulpes (by itself) is BAD…need genus + species.