Monday, November 21, Taxonomy & Classification Packet #32 © Ryan Barrow 2008

Monday, November 21, Diversity How are organisms related? How are organisms different? How and why do we divide organisms into groups? © Ryan Barrow 2008

Monday, November 21, Classification Provides scientists with a means for sorting and grouping these organisms for easier study Names and orders organisms in a logical order. Process of assigning organisms into groups based on their similarities or relationships. © Ryan Barrow 2008

Systematics Scientific study of the diversity of organisms and their evolutionary relationships. Biodiversity The variety of living organisms and the ecosystems they form. Taxonomy Branch of systematics The science of naming organisms and assigning them to groups Classification II

Classification III Why important? Allows biologists from countries of different languages an opportunity to communicate.

Monday, November 21, Nomenclature In order to keep track of millions of species that have been discovered and classified, a system of naming (nomenclature) has been developed that uses the scheme of classification as its basis. System of naming uses two names Binomial nomenclature Devised by Carolus Linnaeus in the 18th century Genus--First letter always capitalized species--all letters are lowercase Latin Homo--Human sapian--Wise © Ryan Barrow 2008

Taxonomy Taxons The “formal” grouping at a particular level Domain Kingdoms Phylums Class Order Family Genus Species Monday, November 21, 2016 © Ryan Barrow 20087

Three Domain Classification System Archaea Eubacteria Eukarya

The Six-Kingdom Classification System Archaebacteria Eubacteria Protista Fungi Plante Animalia

Introduction to the Three Domain System Domain Archae Kingdom Archaebacteria Has combination of bacteria-like and eukaryotic- like genes May be more closely related to Domain Eukarya Does not have the enzyme RNA polymerase

Phylogeny Monday, November 21, 2016 © Ryan Barrow

Phylogeny One goal of systematics is to reconstruct phylogeny The evolutionary history of a group of organisms from a common ancestor Monday, November 21, 2016 © Ryan Barrow

Phylogeny II Homologous Structures Homology The presence, in two or more species, of a structure derived from a common ancestor Homologous structures suggest a common ancestor Homoplasy Superficial similar characteristics that are not homologous Structures that have evolved independently. Used to classify organisms in the same taxa Monday, November 21, 2016 © Ryan Barrow

Phylogeny III Systematists first examine the characteristics in the largest group Characteristics indicate the most remote common ancestry. Plesiomorphic characters/characteristics Shared ancestral characters/characteristics Features that were present in an ancestral species and remain present in all groups descended from that ancestor Suggest a common distinct ancestor Synapomorphic characters Shared derived characters Traits found in two or more taxa that first appeared in their most common ancestor Indicate a more recent common ancestor Monday, November 21, 2016 © Ryan Barrow

Phylogeny IV Molecular Biology/Systematics Uses methods for comparing macromolecules for assessing evolutionary relationships. Including shared derived characteristics Studies of ribosomal RNA may indicate phylogenies Nucleotide and amino acid sequences may be used as molecular clocks Mitochondrial DNA may also indicate phylogenies Monday, November 21, 2016 © Ryan Barrow

Homologous Genes Monday, November 21, 2016 © Ryan Barrow

Taxa & Evolutionary Relationships Monophyletic taxon Includes all the descendants of the most recent common ancestor Paraphyletic taxon Consists of a common ancestor and some, but not all, of its descendents Polyphyletic Group Organisms have evolved from different ancestors Monday, November 21, 2016 © Ryan Barrow

Comparing & Contrasting Evolutionary Systematics to Phylogenetic Systematics (Cladistics) These are approaches used to analyze and interpret data Evolutionary Systematics Classical evolutionary taxonomy Allow paraphyletic taxons Based on shared ancestral characters as well as shared derived characters. Monday, November 21, 2016 © Ryan Barrow

Comparing & Contrasting Evolutionary Systematics to Phylogenetic Systematics (Cladistics) Phylogenetic Systematics Cladistics Use shared derived characters to reconstruct phylogenies Illustrate branching between taxa Branching points are called nodes Ancestral and derived characters are used to construct cladograms Monday, November 21, 2016 © Ryan Barrow

Cladistics II Devised by German biologists Willi Hennig Four tenets Speciation is the only quantifiable feature of evolution All taxa must be monophyletic Clade Consists of a common ancestor and all its descendants All evolutionary relationships must be measured in terms of recency of common decent Rank of a taxon is automatically determined by the age of the common ancestor Monday, November 21, 2016 © Ryan Barrow

Cladistics III Cladists use the principle of parsimony Choose the simplest explanation to interpret the data When interpreting cladograms, the relationships among taxa are determined by tracing along the branches back to the most recent common ancestor (node). The cladogram indicates which taxa shared a common ancestor and how recently they shared that ancestor. Monday, November 21, 2016 © Ryan Barrow

Monday, November 21, Important Vocabulary Autotroph Organism that obtains organic food molecules without eating other organisms. Two classes Chemoautotroph Produce food/energy from chemicals found in their environment Photoautotrophs Produce food/energy from light via photosynthesis Heterotroph An organism that obtains organic food molecules by eating other organisms or their by-products. © Ryan Barrow 2008

Monday, November 21, Important Vocabulary Prokaryote An organism (cell) that lacks membrane bound organelles Eukaryote An organism (cell) with a membrane- enclosed nucleus and other organelles These cells are present in plants, fungi, animals--hence these organisms are called eukaryotes © Ryan Barrow 2008

Monday, November 21, Kingdoms The class will be introduced to the 6 Kingdom System © Ryan Barrow 2008

Monday, November 21, Kingdom Archaebacteria “archae” means ancient Extremely old group These bacteria survive in extreme environments Structure/Shape Prokaryotes Rods Spirilla (spiral) Cocci © Ryan Barrow 2008

Monday, November 21, Kingdom Archaebacteria Nutrition Autotrophs Reproduction Asexual Reproduction © Ryan Barrow 2008

Monday, November 21, Kingdom Archaebacteria Examples Chemoautotrophs Methanogens Live in the deep areas of the ocean where there is no sunlight Thermophiles Photoautotrophs Halophiles Live in some of the most extreme conditions Great Salt Lake (Utah) Dead Sea Salt content is extremely high in these bodies of water © Ryan Barrow 2008

Monday, November 21, Kingdom Eubacteria Known as the “disease causing agents” Only a few of these organisms actually cause diseases Structure/Shape Prokaryotes Rods Spirilla (Spiral) Cocci Bacilli © Ryan Barrow 2008

Monday, November 21, Kingdom Eubacteria Nutrition Autotrophs Heterotrophs Oxygen Requirement Aerobic Require oxygen for respiration Anaerobic Does not require oxygen Movement Via flagella Also found on sperm © Ryan Barrow 2008

Monday, November 21, Kingdom Eubacteria Examples Rickettsias Carried by ticks, fleas or flies Causes Rocky Mountain Spotted Fever Cyanobacteria Converts Nitrogen gas into ammonia, nitrates or nitrites Remember the Nitrogen Cycle? Found in the rice patties of Asia (where rice is grown) Rice feeds 75% of the human population Some species produce toxins dangerous to humans © Ryan Barrow 2008

Monday, November 21, Kingdom Eubacteria Examples Clostridia Clostridium tetani Causes tetnus Clostridium perfringens Causes gas gangrene Causes food poisoning A spore-forming, toxin-producing bacterium that can contaminate meat left at room temperature. The ingested cells release toxin in the digestive tract, resulting in cramps and diarrhea Clostridium botulinum Causes botulism Used in botox injections © Ryan Barrow 2008

Monday, November 21, Clostridum perfringens © Ryan Barrow 2008

Gas Gangrene Monday, November 21, © Ryan Barrow 2008

Monday, November 21, Kingdom Protista Details to come in Packet #6 © Ryan Barrow 2008

Monday, November 21, Kingdom Fungi Considered as the “kingdom of lower plants Organisms live as parasites, symbionts or saphrophytes Structure/Shape Unicellular or Multicellular Heterotrophs Contain cell walls with no cellulose Reproduction Asexual and/or Sexual Reproduction © Ryan Barrow 2008

Monday, November 21, Kingdom Fungi Some are pathogenic to humans and plants because they release poisonous toxins Superficial Mycoses Ring worm Caused by Tinea nigra Subcutaneous Mycoses Lesions that appear at the site of inoculation/infection Ergot (Plants) Fungus that infects various cereal plants © Ryan Barrow 2008

Monday, November 21, Kingdom Fungi Examples Phylum Zygomycota Bread mold Phylum Ascomycota Yeasts Yeast infection anyone? Positive impacts of Fungi Source of antibiotics Penicillin Source of vitamins and enzymes Used in the production of alcohol, vinegar and cheese. © Ryan Barrow 2008

Kingdom Fungi Division Zygomycota Monday, November 21, © Ryan Barrow 2008

Monday, November 21, Kingdom Fungi Division Ascomycota © Ryan Barrow 2008

Monday, November 21, Kingdom Plante Structure/Shape Mainly autotrophs Exception Venus Fly Trap Eukaryotes Multicellular Have cell walls that contain cellulose © Ryan Barrow 2008

Monday, November 21, Kingdom Plante Reproduction Sexual Gametophytes Display “alternation of generations” Cells alternate between haploid and diplod states Definition to come later Asexual African violets © Ryan Barrow 2008

Monday, November 21, Kingdom Animalia Structure/Shape Heterotrophs Eukaryotes Multicelluar Have members without cell walls Reproduction Sexual Humans Asexual Hydra © Ryan Barrow 2008

Monday, November 21, Interaction Between Organisms Food Chain The pathway along which food is transferred from trophic level to trophic level starting with producers Green plant absorbs sunlight Herbivore consumes plant Carnivore consumes herbivore Several more carnivores may be here Final Link--saprophyte organism © Ryan Barrow 2008

Food Chain Monday, November 21, 2016 © Ryan Barrow

Monday, November 21, Food Web Interconnected feeding relationships Map of various food chains connected together © Ryan Barrow 2008

Monday, November 21, Players of the Food Web I Organisms in the Food Web can be categorized as follows Producer Responsible for trapping sun’s radiant energy Green Plants; algae © Ryan Barrow 2008

Monday, November 21, Players of the Food Web II Consumer Include Herbivores Primary consumer 1st to trap energy trapped by producers Carnivores Secondary consumers Do not have direct access to plant energy Omnivores May either be primary or secondary consumers Primary when they eat plant matter Secondary when they eat animal matter © Ryan Barrow 2008

Monday, November 21, Players of the Food Web III Decomposers Include saprophytic fungi and bacteria Responsible for breaking down dead carcasses to simpler forms to be used by other living things Recyclers © Ryan Barrow 2008

Food Web Monday, November 21, © Ryan Barrow 2008

Monday, November 21, Kingdoms… To be Continued More on Kingdoms Protista, Plante & Animalia to come. © Ryan Barrow 2008