1. SYSTEMATICS
AND
PHYLOGENY

2. Upon first glance, one would probably classify this as a…________, but…

3. Organizing Life
____________________ is the branch of biology concerned with identifying, naming, and classifying organisms.
Remember?...
Gray Wolf:
________________-Eukarya, _______________-Animalia, _______________-Chordata, ______________-Mammalia, _______________-Carnivora, _______________-Canidae, _______________-Canus, _______________-lupus
What are taxa?
Some describe the groups as being “_____________________” because one group exists within another group.

4. Think of your “global” address
Species:
Panthera
pardus
Genus: Panthera
Family: Felidae
Think of your “global” address
Order: Carnivora
Class: Mammalia
Figure 26.3 Hierarchical classification
Phylum: Chordata
Kingdom: Animalia
Bacteria
Domain: Eukarya
Archaea

5. Taxonomy’s Binomial System
In the mid-eighteenth century, Carolus Linnaeus developed the binomial system of nomenclature to classify organisms
First word is the __________________
The second word is the _______________ ___________________: This refers to one species (of potentially many) within its genus
A species is referred to by the full binomial name (Genus + species)
Genus name can be used alone to refer to a group of related species
What do the Genus and species actually specify?

6. IMPORTANT-

7. Why are scientific names needed?
Lilium canadense
Lilium bulbiferum
What is the difference in these fish?
-Common names vary both locally and globally
-Languages vary
-Similar to the need for the metric system of measurements
Jellyfish
Crawfish
Silverfish

8. –also known as _____________
Classification lists the unique characters of each taxon and is intended to reflect phylogeny, but…
_____________ is an analytical branch of biology that relies on ____________________________________________________ to determine evolutionary history and relationships
–also known as _____________
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
(All): © Sylvia S. Mader

9. Deciphering evolutionary history
It is often represented as a ___________________________:
A diagram indicating lines of descent
Each branching point is a divergence from a ______________ ______________
It represents an organism that gives rise to two new groups. It is also called a ________

10. __________________characters:
Two types of characters used to construct a tree are:
__________________characters:
Present in some members of a group, but absent in the common ancestor
These traits “were not seen previously”
_________________ characters:
Present in all members of a group and present in the common ancestor (ancestral traits)
When inferring evolutionary relationships, it is useful to know in which clade a shared derived character first appeared
Lancelet
Lamprey
Tuna
Figure 26.5 How to read a phylogenetic tree
Salamander
Turtle
Leopard

11. Canis lupus Order Family Genus Species ALL THESE SPECIES ARE HERE
Felidae
Panthera
Pantherapardus
Taxidea
Taxidea
taxus
Carnivora
Mustelidae
Lutra lutra
Lutra
THIS IS THE
OF ALL SPECIES PICTURED HERE
Figure 26.4 The connection between classification and phylogeny
Canis
latrans
Canidae
Canis
TAXA
Canis
lupus

12. Canis lupus Order Family Genus Species Felidae Panthera Pantherapardus
Taxidea
Taxidea
taxus
Carnivora
Weakness of basic phylogenetic tree:
Mustelidae
Lutra lutra
Lutra
Figure 26.4 The connection between classification and phylogeny
Canis
latrans
Canidae
Canis
Can’t be sure otter evolved before wolf
Canis
lupus
Also, sister taxa do not mean one came from another!

13. How do we know that the construction of a phylogenetic tree is the best hypothesis of phylogeny?
One way is through ___________________. This is a method that uses shared and derived traits to hypothesize evolutionary history. This will usually consider the simplest solution, __________________________________, in the evolutionary history of your groups of organisms being studied.
Species
ingroup
lancelet (outgroup)
chimpanzee
crocodile
dog
finch
lizard
frog
tuna
Your groups will be called a _____________________________ and they represent a common ancestor and all of its descendant lineages.
Biologists can construct _______________________________ to visually represent the derived characteristics of your clade.
mammary glands
hair
gizzard
epidermal scales
Traits
amniotic egg
We’ll always need to select an __________________________: a species from an evolutionary heritage that diverged before the lineage we are studying – called the __________________________________
four limbs
vertebrae
notochord in
embryo

14. Fig. 19.6 enlarged brain hair, mammary glands chimpanzee Amniotic egg
common ancestor
hair, mammary glands
chimpanzee
Amniotic
egg
long canine teeth
terrier
feathers
gizzard
finch
four limbs
crocodile
epidermal
scales
lizard
vertebrae
frog
common
ancestor
tuna
lancelet (outgroup)

15. 3. A __________________ group includes taxa with different ancestors.
1. A __________ is a _______________ group. It consists of an ancestral species and ALL of its descendants.
3. A __________________ group includes taxa with different ancestors.
2. A ________________ group consists of an ancestral species and some, but not all of its descendants
CLADES VS. GROUPS A A A B
Group I B B
Figure Monophyletic, paraphyletic, and polyphyletic groups C C C D D D E E
Group II E
Group III F F F G G G

16. CLADE OR NOT? D D D B B B E E E C C C A F A F A F H H H G G G I I I
common ancestor

17. Which species has gone through the most genetic change?
In some trees, the length of a branch can reflect the number of genetic changes that have taken place in a particular DNA sequence in that lineage
Drosophila
Lancelet
Zebrafish
542 mya
Figure Branch lengths can indicate relative amounts of genetic change
Frog
Which species has gone through the most genetic change?
Chicken
251 mya
Human
Mouse

18. Percentage differences between sequences Human 30% 40%
Mushroom
Tulip
Percentage differences between sequences
Human
30%
40%
Mushroom
40%
Tulip
What is maximum parsimony?
What is maximum likelyhood?
Comparison of possible trees
15% 5% 5%
Figure Trees with different likelihoods
15%
15%
10%
20%
25%
Tree 1:
Tree 2:

19. Remember that phylogenetic tree are _____________
Remember that phylogenetic tree are _____________. As new information is found, these hypotheses can be _____________ or ________________. The best hypotheses for phylogenetic trees fit the most data: morphological, molecular, and fossil. This has been applied to infer features of dinosaurs from birds like me.

20. What kind of data allows us to infer phylogenic information?
_______________
_________________
Genes or other DNA sequences are also homologous if they are descended from a common ancestor
_______________ structures: Bones in the forelimbs of mammals
Beware the analogous
__________________ evolution results in this

22. ______________: Good, but incomplete
______________: Good, but incomplete. It is often difficult to determine the phylogeny of a fossil. Typically, hard parts are mineralized. Soft tissued organisms tend to decay before they are buried.
Watch TED-ed:
How to fossilize yourself

23. Analagous scenarios can also exist in molecular data:
Coincidences:
Molecular
homoplasies

24. Molecular Data Systematics assumes: Immunological techniques
___________________ Comparisons
Systematics assumes:
Two species with similar base-pair sequences are assumed to be closely related
Two species with differing base-pair sequences are assumed to be only distantly related
Mitochondrial DNA (mtDNA) often looked at as well because mutation rate is 10x that of DNA
______________ Comparisons
Immunological techniques
Degree of cross reaction used to judge relationship
Amino acid sequencing
Similar sequence in same protein indicates close relationship (cytochrome C)
Molecular _____________
We use non-adaptive nucleotide sequence mutations (neutral)
Assumed constant rate of mutation over time
Fossil record + matching mutation rate = increased strength in hypothesis

25. Embryology and Development can reveals homologies
Both organisms end up developing an anus form from the blastopore.
anus
Vertebrate
(modern bony fish)
blastopore
Anus develops from
blastopore in both
Echinoderm
(sea star)
Similar embryos
Adult
sea star
anus
Later the echinoderm becomes radially symmetrical

26. A Three Domain System
Historically, scientists (after Aristotle’s time) grouped organisms into two kingdoms, plants and animals
In the late 1800’s a third kingdom, the protists, was added.
In 1969, the five kingdom idea was brought forth.
Basis for placement into a kingdom:

27. Tree of Life Showing The Three Domains
fungi
animals
In the 1970’s the idea of domains based on __________became the prominent idea on how to classify organisms
plants
protists
protists
heterotrophic
bacteria
cyanobacteria
common ancestor

28. Three-Domain System
Sequencing of rRNA suggests all organisms evolved along three distinct lineages:
Domain Bacteria Traits:
Domain Archaea
Domain Eukarya

29. How these domains differ from one another