History of Classification

1
History of Classification

• Taxonomy Branch of biology that names groups
  organisms according to their characteristics
  evolutionary history.
• Aristotle Greek philosopher 2000 years ago,
  classified organisms as plants or animals.
• Animals Land dwellers, water dwellers, air
  dwellers.
• Plants Soft stems, soft woody stems, hard
  woody stems.
• Aristotles classifications were not adequate.

2
Linnaeuss Classification System

• Carolus Linnaeus Swedish naturalist, devised a
  system of grouping organisms into hierarchical
  categories by using morphology more than 200
  years ago.
• Morphology categorized by organisms form and
  structure.
• Greek meaning Morph meaning form
  Logos meaning word.
• Linnaeuss categorization scheme 7 levels of
  organization each more specific than the last.
• Allows organisms to be grouped with similar
  organisms.
• Linnaeuss concentrated on morphology and focused
  on features influenced by genes of common
  ancestry.

3
Linnaeuss Nested Hierarchy

• 7 levels of organization (largest to smallest)
• Kingdom Animal or Plant.
• Subset-Phylum Animal or Division Plant
• Subset-Classes
• Subset-Order
• Subset-Family
• Subset-Genus
• Subset-Species
• Classification Hierarchy of Organisms page 338

4
Binomial Nomenclature

• Linnaeus system,all organisms have a 2 part name
  known as binomial nomenclature.
• Scientific name or species name represent the
  genus and species identifier.
• Genus First part of the name capitalized,
  italics, underlined.
• Species Second part of the name descriptive
  word lower case, italics, underlined, written
  in Latin because it is the same in every
  language.
• Example Homo sapiens means man wise.
• Additional levels have been added to Linnaeuss
  system by taxonomist because of variations in
  some species.
• Botanists split species of plants into subsets
  called varieties.
• Zoologists split some species of animals into
  geographical areas called subspecies.

5
Modern Phylogenetic Taxonomy

• Phylogeny Evolutionary history
• Modern taxonomists use morphology, chromosomal
  characteristics, nucleotide, amino acid
  sequences, embryological development.
• These features are entirely inherited.
• These features with fossil records give reliable
  information to the phylogeny of an organism.
• Phylogenic tree drawing page 343

6
Systematic Taxonomy

• Branch of biology which is the cornerstone of
  phylogenic taxonomy.
• This branch organizes the diversity of living
  things by their evolution.
• Phylogenic Trees Family trees show the
  evolutionary relationships thought to exist among
  groups of organisms.
• Phylogenic trees are subject to change if any
  hypothesis shows new information.
• Phylogenic trees are constructed by comparing
  fossil records, morphology, embryological
  patterns of development, similarity of
  chromosomes.

7
Fossil Record Morphology

• Fossils provide clues to evolutionary history.
• Fossils provide a framework to a phylogenic tree.
• Systematic taxonomists seek to confirm the
  information provided.
• Morphology is studied compared to other
  organisms.
• Homologous features suggest descent from a common
  ancestor.
• The greater number of homologous morphological
  features 2 organisms share the more closely
  related they are.

8
Embryological Patterns of Development

• Differences among animal phyla may appear very
  early in embryological development.
• Zygote (fertilized egg) starts development by
  mitosis. ( sex cell division)
• Blastula - ball of cells that form within a
  matter of hours.
• Blastopore Small indentation that forms on the
  outside of the blastopore that eventually will
  form the digestive system.
• Most animal phyla this indentation will be the
  anterior end of the digestive system.
• Echinoderms (star fish sand dollars)
  chordates (vertebrates) the blastopore becomes
  the posterior end of the digestive system.
• This suggest that echinoderms are more closely
  related to vertebrates than other invertebrates.
• Blastula drawings page 344

9
Chromosomes Macromolecules

• Chromosomes DNA Protein in a coiled
  rod-shaped form that occurs during cell division.
• Macromolecules A very large organic molecule
  composed of many smaller molecules. (DNA, RNA,
  Proteins)
• Karyotypes A chart that shows the pairs of
  chromosomes of organisms.
• Amino Acids 20 different monomer building
  blocks of proteins that share a basic structure.
• The number of amino acid differences is a clue to
  how long ago 2 species split from a shared
  evolutionary ancestor.
• Amino acids can be referred to as a (Molecular
  Clock)
• Karyotype chart page 345

10
Phylogenetic Cladistics

• Uses features of organisms called derived
  characteristics.
• Derived Characteristics feature that evolved
  only within the group.
• Example feathers only on birds.
• It is safe to assume that only feathers evolved
  only on birds.
• Cladograms are charts used by cladistic
  taxonomist.
• Cladogram example page 346.

11
Terms that Describe Life

• Autotroph organism that synthesizes organic
  molecules into inorganic molecules. (makes its
  own food)
• Heterotroph organism that obtains organic
  molecules. (eats food)
• Unicellular living thing composed of one cell.
• Multicellular living thing composed of more
  than one cell.
• Prokaryote unicellular organism that lacks a
  nucleus.
• Eukaryote cell that contains a nucleus
  membrane bound organelles.
• Domain broad groups.

12
6 Kingdom System

• All life on this planet exist in these kingdoms
• Archaebacteria - autotroph heterotroph unicellul
  ar, prokaryote
• Eubacteria - autotroph heterotroph,
  unicellular, prokaryote
• Protist - autotroph heterotroph, unicellular
  multicellular, eukaryote
• Fungi - heterotroph , unicellular
  multicellular, eukaryote
• Plantae - autotroph heterotroph ,
  multicellular, eukaryote
• Animalia heterotroph, multicellular, eukaryote

13
3-Domain System

• Domain Archae
• Domain Bacteria
• Domain Eukarya - (Protist, Fungi, Plantae,
  Animalia)

14
Charts

• Draw the phylogenic tree on page 343.
• Draw the blastula, 2 different blastula cross
  sections the blastopore on page 344.
• Look at the karyotype charts on 345.
• Draw the cladogram on page 346.