1. 20
Phylogeny

2. Phylogeny - evolutionary history of a species or group
systematics classifies organisms and determines evolutionary relationships
Taxonomy is the ordered division and naming of organisms 2

3. Kingdom: Animalia Domain: Bacteria Domain: Archaea Domain: Eukarya
Figure 20.3
Species: Panthera pardus
Genus: Panthera
Family: Felidae
Order: Carnivora
Class: Mammalia
Figure 20.3 Linnaean classification
Phylum: Chordata
Kingdom:
Animalia
Domain:
Bacteria
Domain:
Archaea
Domain:
Eukarya 3

4. Linking Classification and Phylogeny
Systematists depict evolutionary relationships in branching phylogenetic trees 4

5. Cladistics Cladistics classifies organisms by common descent
A clade is a group of species that includes an ancestral species and all its descendants 5

6. Order Family Genus Species Felidae Panthera pardus (leopard) Panthera
Figure 20.4
Order
Family
Genus
Species
Felidae
Panthera
pardus
(leopard)
Panthera
Taxidea
taxus
(American
badger)
Taxidea
Carnivora
Mustelidae
Lutra lutra
(European
otter)
Lutra 1
Figure 20.4 The connection between classification and phylogeny
Canis
latrans
(coyote)
Canidae
Canis 2
Canis
lupus
(gray wolf) 6

7. Each branch point (node) represents the divergence of two taxa
Sister taxa (Sister clades) are groups that share an immediate common ancestor 7

8. where lineages diverge Taxon A
Figure 20.5
Branch point:
where lineages diverge
Taxon A 3
Taxon B
Sister
taxa 4
Taxon C 2
Taxon D 5
Taxon E
ANCESTRAL
LINEAGE 1
Taxon F
Figure 20.5 How to read a phylogenetic tree
Basal
taxon
Taxon G
This branch point
represents the common
ancestor of taxa A−G.
This branch point forms a
polytomy: an unresolved
pattern of divergence. 8

9. Figure 20.10a
A valid clade is monophyletic, signifying that it consists of the ancestor species and all its descendants
(a) Monophyletic group
(clade) A 1 B C D
Figure 20.10a Monophyletic, paraphyletic, and polyphyletic groups (part 1: monophyletic) E F G 9

10. Figure 20.10b
A paraphyletic grouping consists of an ancestral species and some, but not all, of the descendants
(b) Paraphyletic group A B C D
Figure 20.10b Monophyletic, paraphyletic, and polyphyletic groups (part 2: paraphyletic) E F G 10

11. Figure 20.10c
A polyphyletic grouping consists of various taxa with different ancestors
(c) Polyphyletic group A B C D
Figure 20.10c Monophyletic, paraphyletic, and polyphyletic groups (part 3: polyphyletic) E F G 11

12. A shared ancestral character is a character that originated in an ancestor of the taxon
A shared derived character is an evolutionary novelty unique to a particular clade 12

13. Lancelet (outgroup) Lamprey Bass Vertebral column Frog Hinged jaws
Figure 20.11b
Lancelet
(outgroup)
Lamprey
Bass
Vertebral
column
Frog
Hinged jaws
Turtle
Four walking legs
Figure 20.11b Constructing a phylogenetic tree (part 2: phylogenetic tree)
Amnion
Leopard
Hair
(b) Phylogenetic tree 13

14. Euglenozoans Forams Diatoms Ciliates Domain Eukarya Red algae
Figure 20.20
Euglenozoans
Forams
Diatoms
Ciliates
Red algae
Domain Eukarya
Green algae
Land plants
Amoebas
Fungi
Animals
Nanoarchaeotes
Archaea
Domain
Methanogens
COMMON
ANCESTOR
OF ALL LIFE
Thermophiles
Figure The three domains of life
Proteobacteria
(Mitochondria)*
Chlamydias
Spirochetes
Domain Bacteria
Gram-positive
bacteria
Cyanobacteria
(Chloroplasts)* 14

15. No limbs Eastern glass lizard Monitor lizard Iguanas ANCESTRAL Snakes
Figure 20.2
No limbs
Eastern glass lizard
Monitor lizard
Iguanas
ANCESTRAL
LIZARD
(with limbs)
Snakes
Figure 20.2 Convergent evolution of limbless bodies
No limbs
Geckos 15

16. Figure 20.1
Figure 20.1 What kind of organism is this? 16