Classification

There are 13 billion known species, but … There are 13 billion known species, but … Represents only 5% of all organisms that ever lived! Represents only 5% of all organisms that ever lived! New organisms are still being found and identified New organisms are still being found and identified Species of Organisms

What is Classification? Classification is the arrangement of organisms into orderly groups based on their similarities Classification is also known as taxonomy Taxonomists are scientists that identify & name organisms

Benefits of Classifying Accurately & uniformly names organisms Accurately & uniformly names organisms Prevents misnomers (starfish & jellyfish aren't really fish!) Prevents misnomers (starfish & jellyfish aren't really fish!) Uses same language (Latin or some Greek) for all names Uses same language (Latin or some Greek) for all names Sea”horse”??

Confusion in Using Different Languages for Names

Latin Names are Understood by all Taxonomists

Early Taxonomists 2000 years ago, Aristotle was the first taxonomist 2000 years ago, Aristotle was the first taxonomist He divided organisms into plants & animals He divided organisms into plants & animals He subdivided them by their habitat ---land, sea, or air dwellers He subdivided them by their habitat ---land, sea, or air dwellers Factors used to classify objects into a group are called CRITICAL ATTRIBUTES.

Early Taxonomists John Ray, a botanist, was the first to use Latin for naming John Ray, a botanist, was the first to use Latin for naming Names were very long detailed descriptions telling everything about the plant Names were very long detailed descriptions telling everything about the plant

Carolus Linnaeus 18th century taxonomist Classified organisms by their structure Developed naming system which is still used today

Carolus Linnaeus Called the “Father of Modern Taxonomy” Called the “Father of Modern Taxonomy” Developed the modern system of naming known as binomial nomenclature Developed the modern system of naming known as binomial nomenclature Two-word name (Genus & species) Two-word name (Genus & species)

Standardized Naming Genus species Genus species Usually Latin Usually Latin Italicized in print Italicized in print Capitalize genus, but NOT species Capitalize genus, but NOT species Underline when writing Underline when writing Turdus migratorius American Robin

Binomial Nomenclature

Corn Plantae Spermatophyta Magnoliophyta Liliopsida Cyperales Poaceae Zea (Genus) mays (species) Pioneer 32 D 99

Rules for Naming Organisms The International Code for Binomial Nomenclature contains the rules for naming organisms The International Code for Binomial Nomenclature contains the rules for naming organisms All names must be approved by International Naming Congress (International Zoological Congress) All names must be approved by International Naming Congress (International Zoological Congress) This prevents duplicated names This prevents duplicated names

Classification Groups Taxon ( taxa-plural) is a category into which related organisms are placed Taxon ( taxa-plural) is a category into which related organisms are placed There is a hierarchy of groups (taxa) from broadest to most specific There is a hierarchy of groups (taxa) from broadest to most specific Domain, Kingdom, Phylum, Class, Order, Family, Genus, species Domain, Kingdom, Phylum, Class, Order, Family, Genus, species

Classification: Day 2 Critical attributes can be used to categorize objects

What word do these have in common? stick hair ball man wheel high motion poke down water pen soda back light short key wall precious steady cart slow cool house fat stool powder ball pinchairslow fountainstop stone go catfoot

Broadest, most inclusive taxon Broadest, most inclusive taxon Three domains Three domains Archaea and Eubacteria are unicellular prokaryotes (no nucleus or membrane-bound organelles) Archaea and Eubacteria are unicellular prokaryotes (no nucleus or membrane-bound organelles) Eukarya are more complex and have a nucleus and membrane- bound organelles Eukarya are more complex and have a nucleus and membrane- bound organelles Domains

Archaea live in harsh environments and may represent the first cells to have evolved. Sewage treatment plants, thermal vents, etc.

Eubacteria, some of which cause human diseases, are present in almost all habitats on earth. Many bacteria are important environmentally and commercially. Example: E. coli live in the intestines of animals

Economic importance of bacteria include 1) Medication – insulin 2) Food production – cheese, sauerkraut 3) Forensics – increase suspect DNA samples Diseases caused by bacteria include 1) tuberculosis 2) meningitis 3) food poisoning (botulism) 4) strep throat (staphylococcus)

Domain Eukarya is Divided into 4 Kingdoms Protista (protozoans, algae…) Protista (protozoans, algae…) Fungi (mushrooms, yeast …) Fungi (mushrooms, yeast …) Plantae (multicellular plants) Plantae (multicellular plants) Animalia (multicellular animals) Animalia (multicellular animals)

Hierarchy of Taxonomic Groups Domain Kingdom Phylum (Division – used for plants) Class Order Family Genus Species BROADEST TAXON

King Phillip Came Over From Great Spain

Protista (protists) Most are unicellular Most are unicellular Some are autotrophic (plant-like), while others are heterotrophic (animal-like) Some are autotrophic (plant-like), while others are heterotrophic (animal-like) ex: paramecia, ameba, diatoms ex: paramecia, ameba, diatoms

Fungi Multicellular, except yeast Multicellular, except yeast Absorptive heterotrophs (digest food outside their body & then absorb it) Absorptive heterotrophs (digest food outside their body & then absorb it) Cell walls made of chitin Cell walls made of chitin

Plantae Multicellular Multicellular Autotrophic Autotrophic Absorb sunlight to make glucose – Photosynthesis Absorb sunlight to make glucose – Photosynthesis Cell walls made of cellulose Cell walls made of cellulose

Animalia Multicellular Multicellular Ingestive heterotrophs (consume food & digest it inside their bodies) Ingestive heterotrophs (consume food & digest it inside their bodies) Feed on plants or animals Feed on plants or animals

Taxon Each genus contains a number of similar species, with the exception of Homo which only contains modern humans (Homo sapiens) Each genus contains a number of similar species, with the exception of Homo which only contains modern humans (Homo sapiens) evolutionary relationships Classification is based on evolutionary relationships

Basis for Modern Taxonomy Homologous structures (same structure, different function) Homologous structures (same structure, different function) Similar embryo development Similar embryo development Similarity in DNA, RNA, or amino acid sequences (proteins) Similarity in DNA, RNA, or amino acid sequences (proteins)

Homologous Structures show similarities in mammals.

Similarities in Vertebrate Embryos Developing young are immersed in an aquatic environment whether in an egg or a uterus, so similarities exist.

Cladogram Diagram showing how organisms are related based on shared, derived characteristics such as feathers, hair, or scales

Dichotomous Keys Used to identify organisms Used to identify organisms Characteristics given in pairs Characteristics given in pairs Read both characteristics and either go to another set of characteristics OR identify the organism Read both characteristics and either go to another set of characteristics OR identify the organism

Example of Dichotomous Key 1a Tentacles present – Go to 2 1b Tentacles absent – Go to 3 2a Eight Tentacles – Octopus 2b More than 8 tentacles – 3 3a Tentacles hang down – go to 4 3b Tentacles upright–Sea Anemone 4a Balloon-shaped body–Jellyfish 4b Body NOT balloon-shaped - 5