1. The evolutionary history of a species or a group of species
Ch 26 Phylogenetics
The evolutionary history of a species or a group of species

2. Binomial Nomenclature
Linnaeus
Taxonomy: classification
Domains>kingdoms>phyla>classes>orders> families: Genera>Species

3. Canis lupus Order Family Genus Species Felidae Panthera Pantherapardus
Fig. 26-4
Order
Family
Genus
Species
Felidae
Panthera
Pantherapardus
Taxidea
Taxidea
taxus
Carnivora
Mustelidae
Lutra lutra
Lutra
Canis
latrans
Canidae
Canis
Canis
lupus

4. Branch point (node) Taxon A Taxon B Sister taxa Taxon C ANCESTRAL
Fig. 26-5
Branch point
(node)
Taxon A
Taxon B
Sister
taxa
Taxon C
ANCESTRAL
LINEAGE
Taxon D
Taxon E
Taxon F
Common ancestor of
taxa A–F
Polytomy

5. Phylogeny Nodes are ancestors
Polytomy: a branch point from which more than two groups emerge and evolutionary relationships are not clear
Based on DNA

6. What we can and cannot learn
1. no indicator of absolute age
2. can show most recent common ancestor
3. time is proportional to lengths of branches
4. cannot assume how much evolutionary change has occurred in a branch
5. Simply pattern of descent

7. Sorting Homology from Analogy
6. are inferred from morphological and molecular data
Convergent evolution: analogy
Moles: marsupial and placental
Birds and Bats

8. cladistics Common ancestry is the primary classification system
Monophyletic: a taxon is =a clad if it consists of an ancestral species and all its descendents
Paraphyletic: a group of ancestral species and some of its descendents
Polyphyletic: group which includes taxa with different ancestors

9. (a) Monophyletic group (clade) (b) Paraphyletic group
Fig A A A B
Group I B B C C C D D D E E
Group II E
Group III F F F G G G
(a) Monophyletic group (clade)
(b) Paraphyletic group
(c) Polyphyletic group

10. Shared ancestral vs derived characters
Shared ancestral characteristic: originated in the ancestor of the taxon (vertebrates)
Shared derived character: evolutionary novelty unique to a particular clade (hair)

11. Maximum parsimony and Maximum Likelihood
Parsimony: investigate the simplest explanation that is consistent with the facts
Morphologically means a parsimonious tree has the fewest events (shared derived)
Based on DNA: the fewest base changes
Likelihood: assume rates of evolution.complex!!!

12. (a) Percentage differences between sequences
Fig
Human
Mushroom
Tulip
Human
30%
40%
Mushroom
40%
Tulip
(a) Percentage differences between sequences
15% 5% 5%
15%
15%
10%
20%
25%
Tree 1: More likely
Tree 2: Less likely
(b) Comparison of possible trees

13. Molecular Clocks Depends on species Depends on generation time
Accumulated mutations
Assume certain rate of evolution: neutral theory
If most mutations are not harmful then they are not a part of natural selection and have no effect on fitness = a clock

14. 3 Domains
Bacteria: prokaryotes related to chloroplasts and mitochondria
Archaea: diverse group of bacteria that occupy diverse,unlikely environments
Eukarya: true nuclei
Much of lifeon Earth has been single celled

15. EUKARYA BACTERIA ARCHAEA Fig. 26-21 Land plants Dinoflagellates
Green algae
Forams
Ciliates
Diatoms
Red algae
Amoebas
Cellular slime molds
Euglena
Trypanosomes
Animals
Leishmania
Fungi
Sulfolobus
Green nonsulfur bacteria
Thermophiles
(Mitochondrion)
Spirochetes
Halophiles
Chlamydia
COMMON
ANCESTOR
OF ALL
LIFE
Green
sulfur bacteria
BACTERIA
Methanobacterium
Cyanobacteria
ARCHAEA
(Plastids, including
chloroplasts)

16. Horizontal Gene transfer
Eukaryotes arose from an endosymbiosis between an early bacterium and archaean
Meaning eukaryotes are simultaneously most closely related to both
Ring would be better than a tree
Try to do 9 on p 555

17. Fig
Bacteria
Eukarya
Archaea 4 3 2 1
Billions of years ago

18. Fig
Eukarya
Bacteria
Archaea