Scientific Classification

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Scientific Classification

• Whats In a Name??

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What are some ways you are classified?

• gender
• age
• social security number
• income
• state/area of residence
• profession

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Why Classify??

• Human nature- we love to put things in their
  place!
• Organization
• Identification
• Less Confusion
• Show Relationships

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Modern Classification

• Linnaeus
• Binomial nomenclature
• Taxon (taxa)
• phylogenetics- the tracing of evolutionary
  relationships

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Haeckel (1894)Three kingdoms Whittaker (1959) Five kingdoms Woese (1977)Six kingdoms Woese (1990)Three domains
Protista Monera Eubacteria Bacteria
Protista Monera Archaebacteria Archaea
Protista Protista Protista Eukarya
Plantae Fungi Fungi Eukarya
Plantae Plantae Plantae Eukarya
Animalia Animalia Animalia Eukarya
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Early history of life

• Solar system 12 billion years ago (bya)
• Earth 4.5 bya
• Life 3.5 to 4.0 bya
• Prokaryotes 3.5 to 2.0 bya stromatolites
• Oxygen accumulation 2.7 bya photosynthetic
  cyanobacteria
• Eukaryotic life 2.1 bya
• Muticelluar eukaryotes 1.2 bya
• Animal diversity 543 mya
• Land colonization 500 mya

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Bacteria

• Kingdom Monera?
• Domain Bacteria
• Domain Archaea
• Prokaryotic- no membrane-bound organelles,
  microscopic
• Shape
• cocci (sphere)
• bacilli (rod)
• helical (spiral)

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Archaea Vs. Eubacteria

• Domain Archaea
• no membrane- bound organelles (prok.)
• no peptidoglycan
• do not respond to antibiotics
• extremophiles
• chemoautotrophs, heterotrophs
• 3 main groups methanogens, extreme halophiles,
  extreme thermophiles

• Domain Eubacteria
• no membrane-bound organelles (prok.)
• peptidoglycan in cell walls
• growth inhibited by antibiotics
• diverse metabolism
• 5 main groups spirochetes, chlamydias, gram,
  cyanobacteria, proteobacteria

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Prokaryotes

• Decomposers unlock organics from corpses and
  waste products
• Symbiosis symbiont/host mutualism (, )
  parasitism (, -) commensalism (, 0)
• Disease opportunistic normal residents
  of host cause illness when defenses are weakened
  Kochs postulates criteria for
  bacterial disease confirmation
• exotoxins bacterial proteins that can produce
  disease w/o the prokaryote present (botulism)
  endotoxins components of gram -
  membranes (Salmonella)

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Enter Eukaryotes- Domain Eukarya

• nucleus
• membrane-bound organelles
• larger in size than prokaryotic cells
• fungus, plant, and animal cells

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Kingdom Protista (Domain Eukarya)

• Ingestive (animal-like) protozoa
• Absorptive (fungus-like)
• Photosynthetic (plant-like) alga

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Kingdom Plantae (Domain Eukarya)

• bryophytes (mosses), pteridophytes (ferns),
  gymnosperms (pines and conifers) angiosperms
  (flowering plants)
• Plants multicellular, eukaryotic,
  photosynthetic autotrophs
• Terrestrial colonization
• Vascular tissue
• The seed
• The flower

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Gymnosperms (Kingdom Plantae)

• Cone-bearing plants
• Lack enclosed chambers (ovaries) for seeds
• Ovules and seeds develop on specialized leaves
  called sporophylls
• Ginkgo, cycads, and conifers
• All are evergreens
• Needle-shaped leaves
• Vascular tissue refinement tracheids water
  conducting and supportive element of xylem

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Angiosperms (Kingdom Plantae)

• Most diverse and geographically widespread of all
  plants
• Flowering plants(Phy Anthophyta)
• Monocots 1 embryonic seed leaf (lilies, palms,
  grasses, grain crops)
• Dicots 2 embryonic seed leaves (roses, peas,
  sunflowers, oaks, maples)
• Vascular tissue refinement vessel elements/fiber
  cells

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Kingdom Fungi (Domain Eukarya)

• Heterotrophic by absorption (exoenzymes)
• Decomposers (saprobes), parasites, mutualistic
  symbionts (lichens)
• Hyphae body filaments
  septate (cross walls)
  coenocytic (no cross walls)
• Mycelium network of hyphae
• Chitin cell walls (polysaccharide)

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Fungi Diversity, I

• Phy Chytridiomycota aquatic fungi chytrids
  lineage closest to protists
  (flagella)
• Phy Zygomycota Rhizopus (food mold)
  mycorrhizae mutualistic with plant roots
  zygosporangia resistant structure (freezing
  and drying)

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Fungi Diversity, II

• Phy. Ascomycota sac fungi
  yeasts, truffles, morels, Sordaria
  asci sexual spores
  conidia asexual spores
• Phy. Basidiomycota club fungus
  mushrooms, puffballs, shelf fungus, rusts
  basidiocarps produce sexual spores

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Kingdom Animalia (Domain Eukarya)

• heterotrophic
• most are mobile
• ingestion followed by digestion
• multicellular (most have tissues)
• lack cell walls
• sexual reproduction
• 35 phyla- most are marine

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Animal phylogeny diversity

• Monophyletic colonial flagellated protist
  ancestor
• 1- Parazoa-Eumetazoa dichotomy sponges
  (Parazoa) no true tissues all other animals
  (Eumetazoa) true tissues
• 2- Radiata-Bilateria dichotomy Cnidaria (hydra
  jellyfish sea anemones) Ctenophora (comb
  jellies) radial body symmetry all other
  animals bilateral body symmetry (also
  cephalization)

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Summary

• 3 Domains- but textbooks are behind Bacteria,
  Archaea, and Eukarya
• 6 kingdom system in most texts Eubacteria,
  Archaea, Protista, Fungi, Plantae, Animalia
• classification now based on evolutionary history