1 Classification

2 There are 13 billion known species of organisms There are 13 billion known species of organisms This is only 5% of all organisms that ever lived!!!!! This is 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

3 What is Classification? Classification is the grouping of objects or information based on similarities. (aka taxonomy) Taxonomy is a branch of biology that groups and names organisms based on their characteristics Taxonomists are scientists that identify & name organisms

4 Benefits of Classifying Accurately & uniformly names organisms Accurately & uniformly names organisms Prevents misnomers such as starfish & jellyfish that aren't really fish Prevents misnomers such as starfish & jellyfish that 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”??

5 Confusion in Using Different Languages for Names

6 Latin Names are Understood by all Taxonomists

7 History of Classification Systems: - The way we classify organisms changes as we gather information about: DNA/protein analysis Embryology- study of an organism’s early stage of life Anatomy (body parts)/morphology (form) Phylogeny- evolutionary history of an organism

8 Early Taxonomists 2000 years ago, Aristotle was the first taxonomist 2000 years ago, Aristotle was the first taxonomist Aristotle divided organisms into 2 groups: plants & animals Aristotle divided organisms into 2 groups: plants & animals He subdivided them by their habitat. He subdivided them by their habitat. PlantsAnimals herbsshrubstreesairlandwater

9 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 His names were very long descriptions telling everything about the plant His names were very long descriptions telling everything about the plant

10 Carolus Linnaeus 1707 – th century taxonomist Classified organisms by their structure Developed naming system still used today

11 Carolus Linnaeus Called the “Father of Taxonomy” Called the “Father of 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)

12 Standardized Naming Ex. Homo sapiens Most names are in Latin. Most names are in Latin. 1 st word= genus (capitalized) 1 st word= genus (capitalized) 2 nd word= species (lower case)- usually descriptive 2 nd word= species (lower case)- usually descriptive Both words must be italicized or underlined (if handwritten). Both words must be italicized or underlined (if handwritten). Turdus migratorius American Robin

13 Binomial Nomenclature Which TWO are more closely related?

14 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 Congresses (International Zoological Congress) All names must be approved by International Naming Congresses (International Zoological Congress) This prevents duplicated names This prevents duplicated names

15 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

16 Current System (with human classification): Domain (3) – group of similar kingdoms (Eukarya) Kingdom (7) – group of similar phyla (Animalia) Phylum- group of similar classes (Chordata) Class- group of similar orders (Mammalia) Order- group of similar families (Primates) Family- group of similar genera (Hominidae) Genus- group of similar species (Homo) Species- a group of organisms that can interbreed and produce fertile offspring in nature (H. sapiens)

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

19 Binomial Nomenclature Which TWO are more closely related? Snowshoe hare Lepus americanus Black Bear Ursus americanus

20 Dumb King Phillip Cried Out “For Goodness Sake!”

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

22 Phylogenetic Tree Phylogenetic tree- diagram that shows an organism’s evolutionary history A B C D E F Which 2 organisms are most related? A&B or A&C A&C or C&D

23 Dichotomous Keys Used to identify organisms Used to identify organisms Identification key that contatins pairs of contrasting descriptions Identification key that contatins pairs of contrasting descriptions 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

24 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

25 Can you make your own dichotomous key?