1. Phylogeny and the Tree of Life
AP Biology
Crosby High School

2. Taxonomy Binomial Nomenclature Hierarchical Classification PhyloCode?
Genus specium
Hierarchical Classification
Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species
PhyloCode?

3. Terminology
Dichotomies
Sister Taxa
Rooted
Basal Taxon
Polytomy

4. Cladistic Analysis Clade Cladogram: Phylogenetic diagram Dichotomies
Monophyletic (“single tribe”)

5. Constructing a Cladogram
Created from Homology not Analogy
More similar Homologies are more closely related
The more complex two structures are the more likely they are homologous
Shared Primitive Character: common to more inclusive taxon
Mammal backbone
Shared Derived Character: unique to defined taxon
Mammal hair

6. Outgroup Comparison Outgroup: Very distant from studied Organisms
Ingroup: Studied Organisms
Which one of these things is not like the other?
Ancestor more recent, not species

7. Molecular Cladograms Constructed from differences in DNA sequences
rRNA used for taxa that diverged from 100s to millions of years ago
mtDNA used for more recent divergences
Insertions and Deletions must be accounted for

8. Parsimony Keep it simple
Requires the least amount of changes or evolutions to occur

9. Phylogenetic Trees are Hypotheses
They are a guess
Most parsimonious = most accepted
Unless evidence proves otherwise
The same evolutionary event occuring more than once in unrelated cases is unlikely
Strongest hypotheses are supported by morph., molec., and fossil record

10. Parsimony

11. DNA Allignment

12. Outgroup Comparison