The Science of Classifying Organisms Taxonomy The Science of Classifying Organisms

The Need for a System For many years, scientists and other naturalists used common names to describe organisms confusing because there were either multiple organisms with the same common name (e.g. “rose”), or a single organism with many common names (e.g. Chinook, Spring, King, Tyee salmon). *Check out these slides …..

What would you call this animal? Cougar, Puma, Mountain Lion, Panther, Wild cat, Catamount, Florida Panther, American Lion, Deer Tiger, Brown Tiger, Night Screamer Central and S America, western USA and Canada with remnant population in Florida

Sea Lion? Antlion? Lion? Photo Credits Sea Lion: Bill Lim Ant Lion: Amphioxus Lion: law_keven Sea Lion? Antlion? Lion?

Which one of these is NOT actually a bear? Photo Credits Panda: Chi King Koala: Belgianchocolate Black Bear: SparkyLeigh

Consider this……….. Are all “Grey Wolves” gray? Are all “Black Bears” black? Grey wolves can be white, black and any shade of gray. Black bears can also be brown or gray

Linnaeus to the Rescue After trying other systems, scientists settled on a system developed by the Swedish botanist Carolus Linnaeus. This system was called Binomial Nomenclature which means “two-name naming”.

Binomial Nomenclature Each organism gets its own two-part scientific name – usually derived from Latin. E.g. “cougar” = Puma concolor The first word is called the genus and the second word is called the species. The first letter of the genus is always capitalized. The first letter of the species is always lower case The name is either italicized or underlined.

The Genus Genus refers to a group of closely related species Puma jagouaroundi Puma concolor

Panthera onca Panthera tigris Panthera leo Puma concolor

Binomial Nomenclature Structure Binomial nomenclature gives information about the natural relationships of organisms It shows exactly where an organism sits in the vast complexity of life Today, use genetic analysis for classifying organisms

Naming and Organizing are part of the same process Linnaeus also created a system where we place all organisms into a few *large* groups - KINGDOMS - and then those groups are further divided into smaller groups

Grouping Kingdom Phylum Class Order Family Genus Species Each group gets smaller and more specific – just think of the way you file things on your computer into folders and subfolders

Seven Levels of Classification Kingdom Phylum Class Order Family Genus Species Animalia Chordata Mammalia Carnivora Felidae Panthera tigris Narrower Broader

To help you remember the list Kids Play Catch Over Farmer Grey`s Stable Kingdom, Phylum, Class, Order, Family, Genus, Species

The Kingdoms There are currently 5 kingdoms – all organisms can be placed into one of those 5 Classification into a kingdom is based on certain criteria Cell type Number of cells Nutrition

Kingdom Monera Prokaryotic (do not have a nucleus) Unicellular Autotrophic (produces own energy) or Heterotrophic (obtains energy from food consumed) Eubacteria = common bacteria (E. coli, Salmonella) Archaebacteria = “ancient bacteria”, exist in extreme environments

Kingdom Protista Eukaryotic (have a nucleus) Most are unicellular Can be autotrophic or heterotrophic Most live in water Include animal-like (heterotrophs) and plant-like (autotrophs Examples: Ameba, paramecium, euglena, algae Photo of Ameba by PROYECTO AGUA **/** WATER PROJECT Catch-all group for eukaryotes which don’t fit into other categories

Kingdom Fungae Eukaryotic (have a nucleus) Multicellular (most) Heterotrophic (mainly decomposers) Cell walls have chitin Lack motility Photos by nutmeg66

Kingdom Animalia Eukaryotic (have a nucleus) Multicellular Photo by Tambako the Jaguar Eukaryotic (have a nucleus) Multicellular Heterotrophic (must consume food) Motile (some only in certain stages of life) Lack cell walls Ex: birds, insects, worms, mammals, reptiles, humans Photo by Eduardo Amorim

Kingdom Plantae Eukaryotic (cells have nucleus) Multicellular Autotrophic (can make own food; photosynthesis) Cell walls have cellulose Photo by hira3