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 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 ---land, sea, or air dwellers He subdivided them by their habitat ---land, sea, or air dwellers

8 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

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

10 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)

11 Standardized Naming Binomial nomenclature used Binomial nomenclature used 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

12 Binomial Nomenclature

13 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

14 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

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

16 King Phillip Came Over For Good Soup!

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18 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

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

20 Eubacteria, some of which cause human diseases, are present in almost all habitats on earth. Many bacteria are important environmentally and commercially. Live in the intestines of animals

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

22 Protista Most are unicellular Most are unicellular Some are multicellular Some are multicellular Some are autotrophic, while others are heterotrophic Some are autotrophic, while others are heterotrophic

23 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

24 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

25 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

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28 Taxons Most genera contain a number of similar species, with the exception of Homo that only contains modern humans Most genera contain a number of similar species, with the exception of Homo that only contains modern humans evolutionary relationships Classification is based on evolutionary relationships

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30 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 sequence of Proteins Similarity in DNA, RNA, or amino acid sequence of Proteins

31 Homologous Structures show Similarities in mammals.

32  Show that functionally similar features can evolve independently in similar environments  Analogous structures can be used for the same purpose and can be superficially similar in construction, but are not inherited from a common ancestor.

33 Phylogenic Species Concept  Phylogeny is the evolutionary history of a species.  The phylogenic species concept defines a species as a cluster of organisms that is distinct from other clusters and shows evidence of a pattern of ancestry and descent.  A phylogenetic tree is a graphical representation of the evolutionary relationship between taxonomic groups.

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35 Similarities in Vertebrate Embryos

36 Molecular Clocks  A molecular clock is a model that is used to compare DNA sequences from different species to estimate how long the species have been evolving since a common ancestor.  The differences between the genes indicate the presence of mutations.  The more mutations that have accumulated, the more time that has passed since divergence.

37 Cladogram Diagram showing how organisms are related to a common ancestor based on shared, derived characteristics such as feathers, hair, or scales

38 Primate Cladogram

39 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

40 Example of Dichotomous Key 1a Tentacles present – Go to 2 1b Tentacles absent – Go to 6 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

41 Viruses  A virus is a nonliving strand of genetic material within a protein coat  The protein coat is called a capsid  No organelles to take in nutrients or use energy  Cannot move  Cannot replicate on their own (requires host cell)  Most viruses range in size from 5 to 300 nanometers.

42 Viruses  Common viruses include:  Human Immunodeficiency Virus(HIV) – causes AIDS  Tobacco Mosaic Virus – disease in tobacco plants  Influenza Virus – causes the flu  Bacteriophage-infects bacteria  Rhinovirus-common cold

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