1. Phylogeny Systematics Cladistics
Modern Classification sorts organisms into groups shows relationships among them
Phylogeny
Systematics
Cladistics

2. Classification and Diversity
- tries to organize all living things into groups
- show how they evolved from earlier life forms
- show relationships to other present forms
- changes with new information
Early Systems
Aristotle - by environment: land, water, air
John Ray (1600s) - in related groups
- short description for each species

3. Linnaeus Carolus Linnaeus – Swedish botanist, 1700s
used physical appearance and structure
7 taxa: from broad to specific
Kingdom – Phylum – Class – Order
- Family – Genus – Species
Binomial Nomenclature
- two names for each
Genus: group to which it belongs
species: 1-2 word description
Ex. Homo sapiens

4. Evidence for Classification
Many forms:
- physical appearance and structure (morphology)
- other present organisms
- fossils
- molecules, especially DNA, RNA, proteins
- embryology patterns
Various organizing diagrams

5. Evidence for Evolutionary Relationships
Physical appearance and structure
Resemblance to other organisms

6. Fossils Embryo Development

7. Phylogeny and Systematics
Taxonomy – sort and name organisms
Phylogeny - Evolutionary history of a group of
organisms - shows common ancestry
Systematics - combines taxonomy with evolution
- organized way to study diversity and relationships

8. Taxonomy – sorting and naming
Species – individual type of organism
Genus – group of related species
Scientific Name = Genus & species
Family – related genera
Order – related families
Class – related orders
Phylum – related classes
Kingdom – related phyla
Domain – Three Domain System

9. Phylogeny – evolution history

10. Simplest relationships make the most likely phylogenetic trees

11. Phylogeny -compares structure
Homologous – similar structure, with adaptations - shows common ancestry

12. Analogous structures Evolved in similar environments
NOT shared ancestry

13. Cladistics
Tries to show evolutionary relationships based on physical traits shared by different groups of organisms

14. Cladograms More shared traits = more closely related Derived character
– more recent branch from evolutionary line
Primitive character
- older, shared by more groups

15. Molecular Systematics
Compares molecules to find relationships

16. Ribosomal RNA
Have shown that fungi are more closely related to humans than to green plants
Student
Mushroom
Tulip
Common ancestor
Figure 15.9B

17. DNA – Compare genes and DNA sequences
- many similar sequences = closely related

18. More shared genes = closer relationship
Human
Chimpanzee
Gorilla
Orangutan
Common ancestor
Figure 15.9C

19. Molecular Clocks Some regions of DNA or proteins
Change at a fairly consistent rate
Can date evolutionary events

20. Five- Kingdoms System Prokaryotes are in one Kingdom – Monera
(Classification is a work in progress!)
Prokaryotes are in one Kingdom – Monera
Eukaryotes are grouped in separate kingdoms
Animals, Plants, Fungi, Protists

21. Bacteria are divided into two kingdoms, based on their chemical nature
Six-Kingdom System
Bacteria are divided into two kingdoms, based on their chemical nature

22. Three Domain System One domain for all eukaryotes
One domain for each of the two kinds of bacteria