Phylogeny

1
Phylogeny

• Determined on the basis of similarities in
• Structure
• Breeding behaviors
• Geography
• Chromosomes
• Biochemistry
• All of this evidence allows taxonomists to
  determine relatedness and thus, taxonomy!

2
Cladistics

• Part of Systematics
• Clade evolutionary branch
• Organizes Orgs. In order of evolution
• Defined by novel homologies
• Introduced characteristics called derived
  characters
• Shows evolution of orgs as well as the novel
  characters which define their grouping

3
Cladogram vs. Comparative (Traditional)
Morphology p.452
Derived Characters
lt-- Common Ancestor
? ?
Common Ancestor ?
Common Ancestor ?
4
Cladistics

• A system of classification based on phylogeny
• Uses cladograms
• What does a cladogram tell you?

5
Fan Diagrams

• How are fan diagrams different from cladograms?

6
The 6 kingdom debate

• The discovery of Archaea led one team of
  scientists, led by Carl Woese, to propose a new
  taxa
• DOMAIN (SUPERKINGDOM)
• ABOVE KINGDOM

7
Three Domain System

• 1990s
• Domain is larger classification than Kingdom
• Used Technology to compare Ribosomal RNA
  sequences of organisms from bacteria to animals
• Determined how long organisms had been evolving
  independently
• Shows Evolutionary Relationships
• Uses molecular clock to determine how long ago
  orgs were related
• Based on how many sequences are different ( of
  mutations, order of mutations)

8
Three Domain System

• 1. Domain Bacteria
• Corresponds to Eubacteria Kingdom
• Unicellular Prokaryotic Organisms
• No Nucleus
• Ecologically Diverse live everywhere!
• Metabolically Diverse
• Cell Walls contain substance called Peptidoglycan
  special protein and sugar
• Trait used to distinguish between
• Bacteria and Archaea
• Target of many Antibiotics

9
Three Domain System

• 2. Domain Archaea Ancient Bacteria
• Corresponds to Kingdom Archaeabacteria
• Unicellular, Prokaryotes
• Metabolically Diverse
• No nucleus
• Live in Extreme environments like those of early
  Earth
• Cell walls without Peptidoglycan
• A trait used to distinguish between Archaea and
  Bacteria Domains

10
Three Domain System

• 3. Eukarya
• Contains Kingdoms
• Protista, Fungi, Plantae, Animalia
• Eukaryotic, single or multi-cellular Organisms
• Nucleus
• Most visible life
• Humans are in Domain Eukarya