Taxonomy The science of naming organisms.

Aristotle – Simple Classification Plant or animal? If an animal, does it –Fly –Swim –Crawl Simple classifications Used common names

Carolus Linnaeus – Scientific Names Described organisms with two word names, instead of polynomials Developed Binomial Nomenclature BI – 2NOMIAL - Name First word = Genus Second word = species EX: Balenopora physalus – Felis catus Blue Whale - Domestic Cat

Why binomial nomenclature? Much easier than a 10+ word name under old “polynomial system” Same name no matter where you go Less confusion Binomial = SCIENTIFIC NAME = Latin

Scientific Names You Should Know Homo sapiens Cannis familiaris Panthera leo Panthera tigris Panthera pardus

Taxonomic hierarchy Names organisms and their relationships from very broad to very specific – Like an umbrella

All organisms classified in a hierarchy Kingdom (broadest) (most organisms) Phylum Class Order Family Genus Species (most specific)(least organisms)

EACH LEVEL IS CALLED A… PHYLA or TAXA (taxon – pl)

DICHOTOMOUS KEY SERIES OF QUESTIONS (WITH 2 OPTIONS) THAT LEADS TO THE IDENTIFICATION OF AN ORGANISM. BROAD TO SPECIFIC

ACTIVITY CLASS GROUP MALE / FEMALE »LONG HAIR / SHORT HAIR »CURLY / STRAIGHT »LIGHT HAIR / DARK HAIR »DRESS SHOES/ATHLETIC SHOES

What is a species anyway? Biological species concept –SPECIES - group of actually or potentially breeding natural groups that are reproductively isolated from other groups. »Ernst Mayr, 1924 BSC’s problems –Hybrids Sterile offspring of two different species –Asexual organisms

How many are out there? Scientists currently estimate that –There are 10 million species worldwide –Over 5 million live in the tropics –Most unnamed species are small or microscopic

Why is taxonomy useful? Helps prevent confusion among scientists Helps to show how organisms are related Can be used to reconstruct phylogenies – evolutionary histories – of an organism or group

A note on Cladograms Graph showing when different groups diverged from a common ancestral line Based on Derived Traits Hypothesized ancestry – probable evolution Recent common ancestors – adjacent branches

Bird Cladogram

Fan-like Model Uses: Fossil information Anatomonical studies Genetic studies Cladistic studies Identifies relationships between modern & extinct species

The 6 kingdoms Prokaryotes (Used to be 1 kingdom, Monera) –Archaebacteria –Eubacteria Eukaryotes –Fungi –Protista –Animal –Plantae

Overview of the 6 kingdoms Archaebacteria –Unicellular –Live in extreme environments –Prokaryotic Eubacteria –Unicellular –Prokaryotic –“Common bacteria”

Overview of the 6 kingdoms Protista –Eukaryotic –Unicellular or colonial –Lots of different life styles Fungi –Cell walls made of chitin –Eukaryotic –Multicellular –External heterotrophs

Overview of the 6 kingdoms Plantae –Eukaryotic & Multicellular –Cell walls made of cellulose –Autotrophic Animalia –Eukaryotic & Multicellular –No cell walls –Internal heterotrophs