1. The Major Lineages of Life
Molecular data challenges 5 Kingdoms
Monera was too diverse
2 distinct lineages of prokaryotes
Protists are still too diverse
not yet sorted out

2. Chapter 26 Phylogeny and the Tree of Life
Phylogeny is the evolutionary history of a species or group of related species
The discipline of systematics classifies organisms and determines their evolutionary relationships
Systematists use fossil, molecular, and genetic data to infer evolutionary relationships
Taxonomy is the ordered division and naming of organisms

3. 3 Domain system Domains = “Super” Kingdoms Bacteria Archaea Eukarya
extremophiles = live in extreme environments
methanogens
halogens
thermophiles
Eukarya
eukaryotes
protists
fungi
plants
animals

4. Classification Old 5 Kingdom system New 3 Domain system
Eukaryote
Prokaryote
Old 5 Kingdom system
Monera, Protists, Plants, Fungi, Animals
New 3 Domain system
reflects a greater understanding of evolution & molecular evidence
Prokaryote: Bacteria
Prokaryote: Archaebacteria
Eukaryotes
Protists
Plants
Fungi
Animals
Archaebacteria & Bacteria

5. Kingdom Protista
Kingdom Fungi
Kingdom Plantae
Kingdom Animalia
Kingdom Archaebacteria
Kingdom Bacteria

6. Kingdoms Fungi Animalia absorptive nutrition ingestive nutrition
Plantae
autotrophs
heterotrophs
Protista
uni- to multicellular
multicellular
Eubacteria
Archaebacteria
prokaryotes
eukaryotes
Single-celled ancestor

7. Finding commonality in variety
Organisms classified from most general group, domain, down to most specific, species
domain, kingdom, phylum, class, order, family, genus, species
use the mnemonic!

8. The Evolutionary Perspective

9. Phylogenies are inferred from morphological and molecular data
To infer phylogenies, systematists gather information about morphologies, genes, and biochemistry of living organisms
Organisms with similar morphologies or DNA sequences are likely to be more closely related than organisms with different structures or sequences

10. Cladistics Cladistics groups organisms by common descent
A clade is a group of species that includes an ancestral species and all its descendants
Clades can be nested in larger clades, but not all groupings of organisms qualify as clades