Taxonomy Biology 8(A) Taxonomy Learning Objectives • Define taxonomy • Understand the importance of a standardized taxonomic system Taxonomy Taxonomy – the branch of biology that classifies and names living things • Uses characteristics of organisms and a universal system – Every organism has a specific name – Organisms are assigned to levels of classification Common Name vs. Scientific Name Common name – name given to an organism by the people of a certain area • Causes great deal of confusion • Examples: – Mountain lion – Puma – Cougar Linnaeus’ System Carolus Linnaeus – Swedish botanist who developed new classification system that revolutionized taxonomy Contributions • Created two-word (binomial) scientific naming system • Suggested that organisms with similar structures be placed in same taxonomic group Common Name vs. Scientific Name Scientific name – standard name accepted by all scientists Binomial nomenclature – scientific naming system using Latin language • First name – genus • Second name – specific name • Both names – species – Felis concolor or Felis concolor – F. concolor or F. concolor Levels of Taxonomy Kingdom Phylum Class Order Family Genus Species Taxonomy Levels of Classification • Kingdom • Phylum • Class • Order • Family • Genus • Species Classification of Humans: • Animalia • Chordata • Mammalia • Primates • Hominidae • Homo • Homo Sapiens Taxonomy Levels of Classification • Kingdom • Phylum • Class • Order • Family • Genus • Species Levels of Classification • Kings • Play • Chess • On • Fancy • Glass • Squares Taxonomy Importance of a standardized taxonomic system • Needed to orderly classify vast diversity of organisms • Allows for universal understanding • Ability for similarities to be compared • Show common ancestry Taxonomy Learning Objectives • Define taxonomy • Understand the importance of a standardized taxonomic system Classifying Organisms Biology 8(B) Classifying Organisms Learning Objectives • Categorize organisms using a hierarchical classification system based on similarities and differences shared among groups – Using characteristics of major groups – Using dichotomous keys Classifying Organisms Taxonomy – the science of classifying organisms Taxonomists use a seven level classification system • Kingdom • Phylum • Class • Order • Family • Genus • Species Classifying Organisms Comparing the classification of a domestic housecat and a mountain lion: Mountain Lion Domestic Cat Kingdom Animalia Animalia Phylum Chordata Chordata Class Mammalia Mammalia Order Carnivora Carnivora Family Felidae Felidae Genus Felis Felis Specific name concolor domesticus Classifying Organisms Comparing the classification of the wolf and a polar bear: Wolf Polar Bear Kingdom Animalia Animalia Phylum Chordata Chordata Class Mammalia Mammalia Order Carnivora Carnivora Family Canidae Urisdae Genus Canis Ursus Specific name lupis maritimus Taxonomic Groups All living organisms are grouped into one of a few major categories. • Most widely accepted classification system used by taxonomists groups organisms into six major groups or kingdoms – – – – – – Archaea Bacteria Protista Fungi Plantae Animalia Archaea Archaea – single-celled microorganisms Image by Wing-Chi Poon [CC-BY-1.0] • Examples: – Methane-producing archaea – Sulfur-producing archaea – Thermophiles Characteristics • Microscopic • Many live in extreme environments • Unicellular prokaryotes • Unique cell wall • Autotrophs or heterotrophs Bacteria Bacteria – single-celled microorganisms • Examples: – – – – E. coli Salmonella Streptococcus Staphylococcus Characteristics • Microscopic • Unicellular prokaryotes • Cell wall made of peptidoglycan • Autotrophs or heterotrophs Protista Protista – most diverse kingdom • Examples: – – – – Algae Paramecia Amoeba Diatoms Characteristics • Unicellular or multicellular • Eukaryotes • Autotrophic or heterotrophic • Some have cell walls • Many are microscopic • Many are aquatic • Some are motile Fungi Fungi – similar to plants but not photosynthetic Characteristics • All eukaryotes – Some unicellular – Most multicellular Image by Maciej Lewandowski [CC-BY-1.0] • Examples: – Mushrooms – Yeasts – Molds • Cell wall made of chitin • Absorb nutrients • Many are saprobes • All sessile Plantae Plantae – both vascular and nonvascular plants Characteristics • All eukaryotes – Most multicellular – Some unicellular Image by Eric Guinther [CC-BY-1.0] • Examples: – – – – Mosses Ferns Conifers Flowering plants • Cell wall made of cellulose • Photosynthetic autotrophs • Contain chloroplasts • Sessile Animalia Animalia – most complex kingdom • Vertebrates • Invertebrates Image by Eric Guinther [CC-BY-1.0] • Examples: – – – – Mammals Birds Insects Worms Characteristics • Multicellular (eukaryotes) • No cell walls • Heterotrophic • Most are motile Taxonomic Groups Group (Kingdom) Archaea Bacteria Protista Fungi Plantae Animalia Major Characteristics Examples Prokaryotes, cell wall, may live in extreme environments, unicellular, autotrophs or heterotrophs Prokaryotes, cell wall made of peptidoglycan, unicellular, autotrophs or heterotrophs Methane-producing archaea, thermophiles E. coli, salmonella Eukaryotes, unicellular or multicellular, Algae, paramecia, euglena, autotrophs or heterotrophs, some have cell wall, diatoms many are microscopic Eukaryotes, most are multicellular, cell walls, Mushrooms, molds, yeasts absorbs nutrients through cell wall, sessile Eukaryotes, most are multicellular, cell walls composed of cellulose, photosynthetic, autotrophs Eukaryotes, multicellular, heterotrophs, most are motile Ferns, mosses, conifers, flowering plants Mammals, birds, insects, worms, sponges What kingdom does this organism belong to? A new organism is discovered by a microbiologist. The organism is unicellular, lacks chloroplasts, and has no cell wall. Into which of the six kingdoms should this organism be placed? Group (Kingdom) Archaea Major Characteristics Examples Bacteria Prokaryotes, cell wall made of peptidoglycan, unicellular, autotrophs or heterotrophs Protista Eukaryotes, unicellular or multicellular, autotrophs or Algae, paramecia, euglena, diatoms heterotrophs, some have cell wall, many are microscopic Fungi Eukaryotes, most are multicellular, cell walls, absorbs nutrients through cell wall, sessile Mushrooms, molds, yeasts Plantae Eukaryotes, most are multicellular, cell walls composed of cellulose, photosynthetic, autotrophs Ferns, mosses, conifers, flowering plants Animalia Eukaryotes, multicellular, heterotrophs, most are motile Mammals, birds, insects, worms, sponges Prokaryotes, cell wall, may live in extreme environments, Methane-producing archaea, unicellular, autotrophs or heterotrophs thermophiles E. coli, salmonella What kingdom does this organism belong to? An organism is found growing on your bathroom wall. It is multicellular, and does not appear to be moving. What kingdom do you think it belongs in? Group (Kingdom) Archaea Major Characteristics Examples Bacteria Prokaryotes, cell wall made of peptidoglycan, unicellular, autotrophs or heterotrophs Protista Eukaryotes, unicellular or multicellular, autotrophs or Algae, paramecia, euglena, diatoms heterotrophs, some have cell wall, many are microscopic Fungi Eukaryotes, most are multicellular, cell walls, absorbs nutrients through cell wall, sessile Mushrooms, molds, yeasts Plantae Eukaryotes, most are multicellular, cell walls composed of cellulose, photosynthetic, autotrophs Ferns, mosses, conifers, flowering plants Animalia Eukaryotes, multicellular, heterotrophs, most are motile Mammals, birds, insects, worms, sponges Prokaryotes, cell wall, may live in extreme environments, Methane-producing archaea, unicellular, autotrophs or heterotrophs thermophiles E. coli, salmonella What kingdom does this organism belong to? Rana pipiens is an organism about the size of your hand. Its cells are eukaryotic and it eats other members of its own kingdom. It is an excellent swimmer. What kingdom does Rana pipiens belong in? Group (Kingdom) Archaea Major Characteristics Examples Bacteria Prokaryotes, cell wall made of peptidoglycan, unicellular, autotrophs or heterotrophs Protista Eukaryotes, unicellular or multicellular, autotrophs or Algae, paramecia, euglena, diatoms heterotrophs, some have cell wall, many are microscopic Fungi Eukaryotes, most are multicellular, cell walls, absorbs nutrients through cell wall, sessile Mushrooms, molds, yeasts Plantae Eukaryotes, most are multicellular, cell walls composed of cellulose, photosynthetic, autotrophs Ferns, mosses, conifers, flowering plants Animalia Eukaryotes, multicellular, heterotrophs, most are motile Mammals, birds, insects, worms, sponges Prokaryotes, cell wall, may live in extreme environments, Methane-producing archaea, unicellular, autotrophs or heterotrophs thermophiles E. coli, salmonella Cladograms Clade – group of related organisms Cladogram – branching diagram showing evolutionary descent C B A Properties of cladogram • Each split represents appearance of new trait(s) • Related organisms are closer together new trait(s) new trait(s) Cladograms Cladogram – branching diagram showing evolutionary descent What can be determined from this cladogram? Lemurs Lorises Tarsiers New world Old world Apes • Primates share Monkeys Monkeys common ancestor • Humans more closely related to apes than to monkeys • Lemurs lack traits common to monkeys Humans Cladograms Cladogram of a group of animals Tuataras Lizards Snakes Crocodiles Birds What can be determined from this cladogram? • Tuataras are not lizards • Birds share common ancestor with reptiles • Snakes are more closely related to lizards than crocodiles Image modified from Benchill [GNU] Dichotomous Key Dichotomous key – tool used to identify organisms • Also called classification key • Helps user observe similarities and differences among organisms • Each step presents a level of identification – Only one of the statements in a step can be true about a single organism Dichotomous Key What is the scientific name of this seashell? Seashell Dichotomous Key Image by Shellnut (Own work) [CC-BY-SA-3.0] 1a Cone-shaped 1b Not cone-shaped Go to 2 Go to 5 2a Outside surface smooth 2b Outside surface rigid Go to 3 Go to 4 3a Surface solid color 3b Surface spotted Conus californicus Conus spurius 4a Surface one color 4b Surface has contrasting stripe Calliostoma supragranulosa Calliostoma annulatum 5a Holes along shell margin 5b No holes along shell margin Haliotis refuscens Go to 6 6a Purple in color 6b Not purple in color Janthina janthina Littorina obtusata Dichotomous Key What is the scientific name of this seashell? Seashell Dichotomous Key Image by Hans Hillewaert (Own work) [CC-BY-SA-3.0] 1a Cone-shaped 1b Not cone-shaped Go to 2 Go to 5 2a Outside surface smooth 2b Outside surface rigid Go to 3 Go to 4 3a Surface solid color 3b Surface spotted Conus californicus Conus spurius 4a Surface one color 4b Surface has contrasting stripe Calliostoma supragranulosa Calliostoma annulatum 5a Holes along shell margin 5b No holes along shell margin Haliotis refuscens Go to 6 6a Purple in color 6b Not purple in color Janthina janthina Littorina obtusata Dichotomous Key What is the scientific name of this seashell? Seashell Dichotomous Key 1a Cone-shaped 1b Not cone-shaped Go to 2 Go to 5 2a Outside surface smooth 2b Outside surface rigid Go to 3 Go to 4 3a Surface solid color 3b Surface spotted Conus californicus Conus spurius 4a Surface one color 4b Surface has contrasting stripe Calliostoma supragranulosa Calliostoma annulatum 5a Holes along shell margin 5b No holes along shell margin Haliotis refuscens Go to 6 6a Purple in color 6b Not purple in color Janthina janthina Littorina obtusata Dichotomous Key Is this animal a vertebrate or invertebrate? If it is a vertebrate, what class does it belong in? Vertebrate Animal Dichotomous Key Image by Dario Sanches (Own Work) [CC-BY-SA-2.0] 1a Spinal column present 1b Spinal column absent Go to 2 Invertebrate 2a Fins and gills present 2b Fins and gills absent Fish Go to 3 3a Scales present 3b Scales absent Reptile Go to 4 4a Feathers present 4b Feathers absent Bird Go to 5 5a Hair or fur present 5b Hair or fur absent Mammal Amphibian Dichotomous Key Is this animal a vertebrate or invertebrate? If it is a vertebrate, what class does it belong in? Vertebrate Animal Dichotomous Key 1a Spinal column present 1b Spinal column absent Go to 2 Invertebrate 2a Fins and gills present 2b Fins and gills absent Fish Go to 3 3a Scales present 3b Scales absent Reptile Go to 4 4a Feathers present 4b Feathers absent Bird Go to 5 5a Hair or fur present 5b Hair or fur absent Mammal Amphibian Dichotomous Key Is this animal a vertebrate or invertebrate? If it is a vertebrate, what class does it belong in? Vertebrate Animal Dichotomous Key 1a Spinal column present 1b Spinal column absent Go to 2 Invertebrate 2a Fins and gills present 2b Fins and gills absent Fish Go to 3 3a Scales present 3b Scales absent Reptile Go to 4 4a Feathers present 4b Feathers absent Bird Go to 5 5a Hair or fur present 5b Hair or fur absent Mammal Amphibian Classifying Organisms Learning Objectives • Categorize organisms using a hierarchical classification system based on similarities and differences shared among groups – Using characteristics of major groups – Using dichotomous keys