1 Classification Chapter 17

2 Almost 2 million species of organisms have been described Almost 2 million species of organisms have been described Thousands more are discovered each year Thousands more are discovered each year The total number of species ranges from 5 to 30 million The total number of species ranges from 5 to 30 million Species of Organisms

3 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

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 Early Taxonomists 2000 years ago, Aristotle was the first taxonomist 2000 years ago, Aristotle was the first taxonomist Aristotle divided organisms into plants & animals Aristotle divided organisms into plants & animals He subdivided them by their habitat -- He subdivided them by their habitat -- Ex) land, sea, or air dwellers

8 Carolus Linnaeus 1707 – th century taxonomist Classified organisms by their form and structure Developed 7 levels of classification Developed naming system still used today

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

10 Standardized Naming Binomial nomenclature uses: Genus species Genus species Latin or Greek Latin or Greek 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

11 Binomial Nomenclature

12 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

13 Hierarchy-Taxonomic Groups Domain Kingdom Phylum Class Order Family Genus Species BROADEST TAXON

14 King Phillip Came Over For Good Spaghetti!

15

16 Two Modern Systems Six Kingdom System Three Domain System

17 The Six Kingdoms:

18 The prefix archae - comes from the Greek word "ANCIENT" Unicellular & Prokaryotic Some are autotrophic and some are heterotrophic Live in extreme environments Sewage treatment plants, thermal vents, etc. KingdomArchaebacteria

19 Kingdom Eubacteria Cause human diseases, are present in almost all habitats on earth Many bacteria are environmentally and commercially.Many bacteria are important environmentally and commercially. Live in the intestines of animals

20 Kingdom Protista  “The odds and ends kingdom”  Dumping ground of organisms that don’t fit into the other kingdoms  Eukaryotic  Unicellular or Multicellular Ex) Algae, Slime molds, Diatoms, and Protozoa

21 Kingdom 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) Decomposers Decomposers Ex) yeast, mold, mildew, & mushrooms Ex) yeast, mold, mildew, & mushrooms

22 Kingdom 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

23 Kingdom Animalia Kingdom 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

24

25 Broadest, most inclusive taxon Broadest, most inclusive taxon Three domains: 1.Archaea 2.Eubacteria are unicellular prokaryotes (no nucleus or membrane-bound organelles) 3.Eukarya are more complex and have a nucleus and membrane- bound organelles Domains

26 Domain Eukarya Domain Eukarya includes: Protista (protozoans, algae…) Protista (protozoans, algae…) Fungi (mushrooms, yeasts …) Fungi (mushrooms, yeasts …) Plantae (multicellular plants) Plantae (multicellular plants) Animalia (multicellular animals) Animalia (multicellular animals)

27

28 Skills Practice 1. List the levels of classification from most broad to most specific. 2. What type of organisms are found in the kingdom Archaebacteria? Are these organisms unicellular or multicellular? 3. What 4 kingdoms are in the Domain Eukarya? 4. What is the difference between an autotroph and a heterotroph? Give an example of each.

29 evolutionary relationships: Classification is based on evolutionary relationships: 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 sequence of Proteins Similarity in DNA, RNA, or amino acid sequence of Proteins

30 Homologous Structures show Similarities in mammals.

31 Similarities in Vertebrate Embryos

32 Phylogenetics- the analysis of the evolutionary or ancestral relationships among a taxon (group). Phylogenetic diagram (tree)- a branching tree that indicates how closely related species are.

33

34

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

36 Primate Cladogram

Let’s Create A Cladogram from the following: Derived Characters segmentedjawshairplacentamulticellularlimbs kangaroo earthworm amoeba lizard cat sponge salmon

38 Dichotomous Keying 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

39 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

40