Classification

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Classification

• Chapter 7

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Classification

• Classification of organisms
• Systematics (Taxonomy)
• The study of the kinds and diversity of organisms
  and of the evolutionary relationships among them
• Nomenclature
• The assignment of a distinctive name to each
  species

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Classification

• Taxonomic Hierarchy
• Carolus Linnaeus
• Father of taxonomy
• Recognized that different species could be
  grouped into broader categories based on shared
  characteristics
• Taxon
• Any grouping of animals that shares a particular
  set of characteristics

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Classification

• Linnaeus recognized five taxonomic categories
• Later scientists added three other categories
• Domain (Broadest)
• Kingdom
• Phylum
• Class
• Order
• Family
• Genus
• Species (Most specific)

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Classification

• Nomenclature
• Binomial system
• Problems
• Common names vary
• Crayfish, crawdad, crawfish
• Many common names refer to higher taxonomic
  categories
• Pillbugs

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Classification

• Binomial nomenclature two part naming system
• Each species has a two word name.
• The first word is the Genus and is always
  capitalized
• The second word is the species and is never
  capitalized
• The two words are always either underlined or
  written in italic
• Genus species or Genus species (G. species)
• All words are Latin

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Classification

• Molecular approaches
• Protein and DNA
• Relatedness is based upon commonality
• Common ancestor will be more similar
• Mitochondrial DNA
• Nuclear DNA

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Classification

• Domains
• Archaea
• Prokaryotic microbes that live in extreme
  environments
• Eubacteria
• True bacteria
• Eukarya
• All eukaryotic organisms

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Classification

• The 5 Kingdoms
• Monera
• Protista
• Fungi
• Plant
• Animal

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Classification

• Kingdom of Life
• Monera
• Prokaryotic and unicellular
• Most are heterotrophs
• Bacteria and cyanobacteria make up this kingdom

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Classification

• Protista
• Unicellular or colonies of cells, eukaryotes
• Autotrophs and heterotrophs
• Algae and amoebas are included in this kingdom

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Classification

• Fungi
• Mostly multicellular, eukaryotes
• All are heterotrophs
• Cell walls
• Molds, mildews, mushrooms, and yeasts

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Classification

• Plant
• All are multicellular and eukaryotic
• All are autotrophs
• Cell walls
• Mosses, ferns, cone and flower bearing plants

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Classification

• Animal (Anamalia)
• All are multicellular and eukaryotic
• All are heterotrophs
• Motile
• Mollusk, Annelid, Arthropods, Echinoderms, Fish,
  Amphibians, Reptiles, and Mammals

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Classification

• Animal systematics
• Monophyletic group
• A single ancestral species and all of its
  descendants
• Characters anything that has a genetic basis
  and can be measured
• Polyphyletic group
• Individuals that cannot be traced back to a
  single species
• Paraphyletic group
• Some but not all members of the lineage

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Classification

• Evolutionary systematics
• Resemblance
• Homologies common ancestor
• Analogies evolutionary pressure
• Numerical taxonomy
• Using math to calculate similarity

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Classification

• Phylogenetic systematics (Cladistics)
• Cladogram depicts a sequence in the origin of
  derived characteristics
• Differentiate between analogies and homologies

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Classification

• Symplesiomorphies A character shared by a
  number of groups, but inherited from ancestors
  older than the last common ancestor
• Plesiomorphies an ancestral or primitive
  character
• Outgroup a group that is not included within
  the other group
• Derived Characters characters arriving since
  common ancestry
• Synapomorphies apomorphies shared by all members

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Classification
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Classification

• Patterns of organization
• Symmetry
• Describes how parts of an animal are arranged
  around a point or axis

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Classification

• Asymmetry
• The absence of a central point or axis around
  which body parts are equally distributed
• Ex. Corals, sponges

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Classification

• Radial symmetry
• The arrangement of body parts such that any plane
  passing through the central oral-aboral axis
  divides the animal into mirror images
• Ex. Sea Anemone

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Classification

• Bilateral symmetry
• Arrangement of body parts such that a single
  plane, passing between the upper and lower
  surfaces and through the longitudinal axis of an
  animal, divides the animal into right and left
  mirror images
• Cephalization
• The formation of an anterior end
• Usually results in a head

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Classification

• Unicellular level of organization
• Single celled organisms
• Provide all necessary life functions
• Colonies
• Cellular aggregates
• Some interdependence or division of labor

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Classification

• Diploblastic organization
• Simplest tissue level of organization
• Two layers of cells
• Ectoderm
• Outside layer analogous to epidermis
• Endoderm
• Inside layer analogous to gastrodermis

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Classification

• Triploblastic organization
• Three layers of embryonic tissues
• Mesoderm
• New layer
• Supportive, contractile, and blood
• Organ-system level organization

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Classification

• Types of body cavities
• Acoelomate
• Without body cavity
• Pseudocoelomate
• False body cavity
• Not entirely lined with mesoderm
• Coelomate
• Body cavity surrounded by mesoderm

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Classification

• Higher Animal Taxonomy
• Protosomes early cleavage pattern and
  determination
• Mouth develops from blastopore
• Platyhelminthes
• Nematoda
• Mollusca
• Annelida
• Arthropoda
• Deuterostomes anus develops from blastopore
• Echinodermata
• Hemichordata
• Chordata