Cladistic analysis (Clad Anal 1)

Question 1

What is the aim of cladistics analysis?

Answer 1

To ID plesiomorphic (Ancesterol) state of characters and Apomorphic one (Derived) with relationships between taxa being based on synapomorphies.

Question 2

Apomorphy

Answer 2

derived (evolutionary new) character
state

Question 3

Synapomorphy

Answer 3

Derived CS shared by Ancestors and descendants.

Question 4

Autapomorphy

Answer 4

CS fount in only one OTU

Question 5

Plesiomorphy

Answer 5

CS found outside clade of interest and not useful in systematics.

Question 6

Monophyletic group (clade)

Answer 6

most recent CA and descendent derived from a single ancestral taxon defined by synapomorphies

Question 7

Paraphyletic group

Answer 7

Most recent CA but not all of its descendants. Excludes some members in a group that share this CA

Question 8

Step by step how do you run a Cladistics Analysis?

Answer 8

1. ID transformation series from plesiomorphic to apomorphic state ( a0 –>a1)
2. Code a matrix ( Make the table)
3. Find taxa with the highest # of apomorphic character states.
4. Build cladogram
5. Study distribution of character states in a cladogram (place all on the taxonomic level of the branch)
6. Place apomorphic and autapomorphic stats on the branch to ID mono groups

Question 9

Ad hoc hypothesis

Answer 9

a same derived character state ( observed in 2
taxa (or more) is inherited from CA

Question 10

Parsimony

Answer 10

principle of constructing the simplest possible phylogenetic trees in cladistics.

Question 11

steps = ….

Answer 11

evolutionary transition (equivalent to
number of apomorphies)

Question 12

Answer 12

Question 13

How can we identify and code characters from a morphology?

Answer 13

Several options
* Morpho-anatomical characters
- discrete character = coded as (0) and (1)
e. g. absence (0) or presence (1) of a process

• continuous character = depending on a measure (quantitative)

e. g. size of a process: <1 cm (0); 1 to 5 cm (1); >5
cm (2)

Question 14

Answer 14