Attention BISC 102 students!
! Please sit with your teams (from tutorial), and near your TA!
! Why? For team discussions + easy access to your TA’s help!
D101/D201 = Vahab

D102/202 = Raime

D105/D205 = Matt

D103/D203 = Melanie

D106/D206 = Heather

D104/D204 = Tim
D107 = Seth

1

Week 4: Phylogenetic relationships
This week we’ll learn:
1. How we use phylogenies when classifying life.
2. How to read phylogenetic trees.
3. What data are useful for building phylogenetic trees.
4. How to build and compare phylogenetic trees.

2

1. How we use phylogenies when classifying life
Mini-review: Linnaean classification system
! Species grouped into increasingly large and inclusive taxa, based on homologies (one e.g. of many)
Species:
Panthera pardus aka leopard
Genus: Panthera (cranial features)
Family: Felidae (retractable claws)
Order: Carnivora (carnivorous teeth)
Class: Mammalia (milk and hair)
Phylum: Chordata (nerve/spinal cord)
Kingdom: Animalia (multicellular chemoheterotrophs) Domain: Eukarya (mitochondria and organelles)

3

1. How we use phylogenies when classifying life
Mini-review: Linnaean classification system
! Species grouped into increasingly large and inclusive taxa, based on homologies (one e.g. of many)
Species:
Panthera pardus
Genus: Panthera (cranial features)
Family: Felidae (retractable claws)
Order: Carnivora (carnivorous teeth)
Class: Mammalia (milk and hair)
Phylum: Chordata (nerve/spinal cord)
Kingdom: Animalia (multicellular chemoheterotrophs) Domain: Eukarya (mitochondria and organelles)

Tip: Use a mnemonic device to remember:
Dumb Kids Playing Catch On Freeways Go Splat

4

1. How we use phylogenies when classifying life
Mini-review: Linnaean classification system
! Species grouped into increasingly large and inclusive taxa, based on homologies (one e.g. of many)
Species:
Panthera pardus
Genus: Panthera (cranial features)
Family: Felidae (retractable claws)
Order: Carnivora (carnivorous teeth)
Class: Mammalia (milk and hair)
Phylum: Chordata (nerve/spinal cord)
Kingdom: Animalia (multicellular chemoheterotrophs) Domain: Eukarya (mitochondria and organelles)

Tip: Use a mnemonic device to remember:
Dutifully Keeping Precious Creatures Organized For Grumpy
5
Scientists

1. How we use phylogenies when classifying life
Mini-review: Linnaean classification system
! Species grouped into increasingly large and inclusive taxa, based on homologies (one e.g. of many)
Species:
Panthera pardus
Genus: Panthera (cranial features)
Family: Felidae (retractable claws)
Order: Carnivora (carnivorous teeth)
Class: Mammalia (milk and hair)
Phylum: Chordata (nerve/spinal cord)
Kingdom: Animalia (multicellular chemoheterotrophs) Domain: Eukarya (mitochondria and organelles)

Tip: Use a mnemonic device to remember:
Dirty Kinky People Can Often Find Great Sex

6

1. How we use phylogenies when classifying life
How does this relate to phylogenetic relationships?
! Each higher taxon contains a larger branch of the “tree”, entirely!
! Notice that derived homologous traits are used to define each taxon
**When we classify living things, we use these trees, and these traits**

7

1. How we use phylogenies when classifying life
How does this relate to phylogenetic relationships?
! Each higher taxon contains a larger branch of the “tree”, entirely!
! Notice that derived homologous traits are used to define each taxon
**When we classify living things, we use these trees, and these traits**

A

B

C

E.g. Choose the smallest taxon that includes cats and:
1. Tigers

8

1. How we use phylogenies when classifying life
How does this relate to phylogenetic relationships?
! Each higher taxon contains a larger branch of the “tree”, entirely!
! Notice that derived homologous traits are used to define each taxon
**When we classify living things, we use these trees, and these traits**

A

B

C

E.g. Choose the smallest taxon that includes cats and:
1. Tigers (C)

9

1. How we use phylogenies when classifying life
How does this