7.6,7,8: Cladograms

Question 1

Each line represents a ____

Answer 1

Lineage

Question 2

What are nodes? What do they represent?

Answer 2

• Each branching point

- represent a common ancestor

Question 3

What are clades?

Answer 3

• nodes and all branches from it

Question 4

What do all species of a clade share?

Answer 4

Derived features

Question 5

The ___ is the common ancestor of all species

Answer 5

Root

Question 6

What are sister taxa?

Answer 6

Two clades that emerge from the same node (both share derived trait)

Question 7

What is a basal taxon?

Answer 7

• a lineage that evolved from the root and remains unbranched (no divergence or evolution coming from the root organism)

Question 8

What is synamorphy?

Answer 8

A derived character shared by clade members

Question 9

What is a derived characteristic?

Answer 9

Similarity inherited from most recent common ancestor of an entire group

Question 10

What is an ancestral characteristic?

Answer 10

Similarity that arose prior to the common ancestor

Question 11

Many cladograms and trees include an out group. What is an out group?

Answer 11

• a lineage that is the least closely related to the rest of the organisms

Question 12

What is a monophyletic group?

Answer 12

• includes the most recent common ancestor of the group and all of its descendants (clade)

Question 13

What is a paraphyletic group?

Answer 13

• Includes the most recent common ancestor of the group, but not all its descendants

Question 14

What is a polyphyletic group?

Answer 14

• does not include the most recent common ancestor of all members of the group

Question 15

What is parsimony?

Answer 15

Watered down cheap way of classifying organisms using a tree

Question 16

When do we use the principle of parsimony?

Answer 16

• if there are conflicts among characters

- also use the hypothesis that requires the fewest assumptions (DNA changes)