How do you DO classification?

1. Get with a partner to form a team2. Look over the cards you are given for your team3. Every group gets the same set of 8 cards

• Bob• Sue• Deb• Lou• Jen• Cal• Hal• Val

4. Sort the cards into what you believe may be natural groups• Names do not count, use only shapes shown on card

5. Decide who will tell the class how you sorted your groups• What theme unites/defines each group

Warmup!

How do you DO classification?

Sharing our Results

1. This game is a cross-country race in a forest2. All runners enter the forest by a single south entrance3. The finish line is the northern boundary of the forest4. Runners need not exit at any particular place at the finish5. There are many trails through the woods

• Trails only bifurcate (form two branches) at forks• Trails never join together or rejoin after forking

6. Along the trail straightaways are check-in stations7. At each check-in station, a worker has a unique stamp8. Each runner has a card that is stamped as s/he passes a station9. Runners are not allowed to retrace a path10.All runners must finish the race11.Using the punch cards handed in at the finish line:

• Sketch the trail map• Show all station locations (on the straightaways)• Mark the exit used by each runner

The Forest Meet!

Bob Sue Deb Lou Jen Cal Hal Val

x x x x x x x x

x x x x x

x x

x

x x x x

x x

x

x x

x

x x x

x

x

The Forest Meet

Sharing our Results

Bob Sue Deb Lou Jen Cal Hal Val Total

x x x x x x x x 8

x x x x x 5

x x 2

x 1

x x x x 4

x x 2

x 1

x x 2

x 1

x x x 3

x 1

x 1

The Forest Meet

Sharing our Results

The Forest Meet

Sharing our ResultsRunners can finish anywhere along this northern edge

Start

All of the runners passed the circle station, so this

station must be near the start

Bob Sue Deb Lou Jen Cal Hal Val Total

x x x x x x x x 8

x x x x x 5

x x 2

x 1

x x x x 4

x x 2

x 1

x x 2

x 1

x x x 3

x 1

x 1

The Forest Meet

Sharing our Results

The Forest Meet

Sharing our ResultsRunners can finish anywhere along this northern edge

Start

Five of the runners passed the teardrop station, but three did not, so our 8 runners must have divided into two

groups

Sue, Lou, Jen, Hal, ValBob, Deb, Cal

Bob Sue Deb Lou Jen Cal Hal Val Total

x x x x x x x x 8

x x x x x 5

x x 2

x 1

x x x x 4

x x 2

x 1

x x 2

x 1

x x x 3

x 1

x 1

The Forest Meet

Sharing our Results

The Forest Meet

Sharing our ResultsRunners can finish

anywhere along this northern edge

Start

Four runners of the group of five passed the diamond station, but Hal did not, so he split away before

this station

Sue, Lou, Jen, Val

Bob, Deb, Cal

Hal

Because paths do not rejoin, Hal is separated and thus we can draw

him at the finish line

Sue, Lou, Jen, Hal, Val

Bob Sue Deb Lou Jen Cal Hal Val Total

x x x x x x x x 8

x x x x x 5

x x 2

x 1

x x x x 4

x x 2

x 1

x x 2

x 1

x x x 3

x 1

x 1

The Forest Meet

Sharing our Results

The Forest Meet

Sharing our ResultsFinish

Line

Start

Sue, Lou, Jen, Val

Bob, Deb, Cal

Hal

Bob, Deb, and Cal all passed the triangle station so it was along the

path they shared

Bob Sue Deb Lou Jen Cal Hal Val Total

x x x x x x x x 8

x x x x x 5

x x 2

x 1

x x x x 4

x x 2

x 1

x x 2

x 1

x x x 3

x 1

x 1

The Forest Meet

Sharing our Results

The Forest Meet

Sharing our ResultsFinish

Line

Start

Sue, Val

Deb, Cal

Hal

Deb, and Cal passed the star station, but Bob did not, so the group divided

Jen, Lou

Bob

Jen and Lou passed the heart station, but Sue and Val passed the spade

station, so the group of four divided

Bob, Deb, Cal

Sue, Lou, Jen, Val

The Forest Meet

The rest are autapomorphiesBob Sue Deb Lou Jen Cal Hal Val Tot

al

x x x x x x x x 8

x x x x x 5

x x 2

x 1

x x x x 4

x x 2

x 1

x x 2

x 1

x x x 3

x 1

x 1

The Forest Meet

Autapomorphies!

Start

Hal

Bob

Cal Deb Jen Lou Sue Val

Deb, Cal

Jen, Lou Sue, Val

Notice the runners are in alphabetical order. But this is not the only solution

All branches can be rotated:e.g.: Lou before JenSue-Val before Jen-Lou

But Wait!

We have one really-slow runner just exiting!

Here is his card…figure out his pathway

The Forest Meet!

Bob Sue Deb Lou Jen Cal Hal Val Ross

x x x x x x x x x

x x x x x x

x x

x

x x x x

x x

x x

x x

x

x x x

x

x x

The Forest Meet

Sharing our Results

The Forest Meet

Start

Hal

Bob

Cal Deb Jen Lou Sue Val

What did Ross do?What is parsimonious?Are our ideas wrong?

Maybe Ross followed Hal..Then hit a rougue station?

Ross

1. This game is a cross-country race in a forest2. All runners enter the forest by a single south

entrance3. The finish line is the northern boundary of

the forest4. Runners need not exit at any particular place

at the finish5. There are many trails through the woods

• Trails only bifurcate (form two branches) at forks

• Trails never join together or rejoin after forking

6. Along the trail straightaways are check-in stations

7. At each check-in station, a worker has a unique stamp

8. Each runner has a card that is stamped as s/he passes a station

9. Runners are not allowed to retrace a path10.All runners must finish the race11.Using the punch cards handed in at the finish

line:• Sketch the trail map• Show all station locations (on the

straightaways)• Mark the exit used by each runner

The Clade Race!1. This game represents the evolution of some related organisms2. The organisms are believed to be a clade (w/common ancestor)

3. The organisms we are using are all extant (none are fossils)

5. We make few assumptions about the evolution pathway • Cladogenesis divides one species into two species • We assume there is no convergent or parallel evolution

6. Anagenesis is expected to occur between generations 7. Evolution shows its record of changes in the genotype 8. The record of evolution in genotype is shown in the phenotype9. Evolution is permanent; we assume no reversals of states 10. In this study, we are using no fossils of extinct clade members

11. Using the phenotypes observed in the extant organisms:

4. We make no assumptions about possible phenotypes observed

• Sketch the cladogram• Show the location of character state transitions

• Show the relationships among the taxa

How do you DO cladistics?

1. Look at a group of organisms that you think are related

2. Find a not-too-distantly related (primitive?) out-group

3. Select characters that will help to distinguish the organisms

4. Polarize the character states by:• Stratigraphic sequence (fossil sequence)• Developmental sequence (ontogeny recaps phylogeny)• Outgroup comparison

5. Build a data matrix

6. Group by number of synapomorphies (shared derived)

7. Sketch possible cladograms

8. Seek simplest (most parsimonious) cladogram

OG

A

B

C

D

E

OG A B C D E

0 0 1 0 0 1

0 0 0 1 0 0

0 1 0 0 0 0

0 1 1 1 1 1

0 0 1 0 0 0

0 1 0 1 1 0

0 0 0 1 1 0

0 1 0 1 1 0

0 0 0 1 1 0

0 1 1 1 1 1

OG A B C D E

0 0 1 0 0 1

0 0 0 1 0 0

0 1 0 0 0 0

0 1 1 1 1 1

0 0 1 0 0 0

0 1 0 1 1 0

0 0 0 1 1 0

0 1 0 1 1 0

0 0 0 1 1 0

0 1 1 1 1 1

OG

ABCDE

-- wide wing-- long tail

We start with our most-synapomorphic character

OG A B C D E

0 0 1 0 0 1

0 0 0 1 0 0

0 1 0 0 0 0

0 1 1 1 1 1

0 0 1 0 0 0

0 1 0 1 1 0

0 0 0 1 1 0

0 1 0 1 1 0

0 0 0 1 1 0

0 1 1 1 1 1

OG

-- wide wing-- long tail

We continue with our next-most-synapomorphic character

ACDBE

-- heavy leg-- wide body

OG A B C D E

0 0 1 0 0 1

0 0 0 1 0 0

0 1 0 0 0 0

0 1 1 1 1 1

0 0 1 0 0 0

0 1 0 1 1 0

0 0 0 1 1 0

0 1 0 1 1 0

0 0 0 1 1 0

0 1 1 1 1 1

OG

-- wide wing-- long tail

We continue with our least-synapomorphic character

CDBE

-- heavy leg-- wide body

-- large eye

-- long leg-- dark body

A

OG A B C D E

0 0 1 0 0 1

0 0 0 1 0 0

0 1 0 0 0 0

0 1 1 1 1 1

0 0 1 0 0 0

0 1 0 1 1 0

0 0 0 1 1 0

0 1 0 1 1 0

0 0 0 1 1 0

0 1 1 1 1 1

OG

-- wide wing-- long tail

We finish with our autapomorphic character

CE

-- heavy leg-- wide body

-- large eye

-- long leg-- dark body

A -- black eye

D

-- wide neck

-- long wing

B

-- wide wing-- long tail

Finally we format our cladogram with extant taxa at the top

-- heavy leg-- wide body

-- large eye

-- long leg-- dark body

-- black eye-- wide neck-- long

wing

OG E B A D C

-- wide wing-- long tail

What do we do with the swapped out Clade Critter?

-- heavy leg-- wide body

-- large eye

-- long leg-- dark body

-- black eye-- wide neck-- long

wing

OG E B A D C

E’

-- wide wing-- long tail

What do we do with the swapped out Clade Critter?

-- heavy leg-- wide body

-- large eye

-- long leg-- dark body

-- black eye-- wide neck-- long

wing

OG E’ B A D C

dark -- body

A homoplasy…A parallelism or….A convergence E’

-- wide wing-- long tail

Is there an alternative explanation?

-- heavy leg-- wide body

-- large eye

-- long leg-- dark body

-- black eye-- wide neck-- long

wing

OG E’ B A D C

E’

dark -- body

A single evolutionBut two reversals

-- dark body

-- dark bodyR

-- dark bodyR

Twoevolutions

Is it easier to evolve or to lose the characteristic?