Lesson test: The shape of history

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The shape of history

1.[3p]
Why can two character-defined groups never overlap partially on a branching history?

Partial overlap would require a species to descend from two different branches

Correct

Characters are always inherited by every descendant

The answer is: Partial overlap would require a species to descend from two different branches

Convergence is impossible

The answer is: Partial overlap would require a species to descend from two different branches

Every character arises only once in the whole tree

The answer is: Partial overlap would require a species to descend from two different branches

2.[2p]
For twenty species there are about $2.2 \times 10^{20}$ unrooted branching patterns. What is the exponent of ten?

CorrectNot quite: 20

3.[3p]
The bat-with-mouse tree needs 8 steps for seven characters. What is its consistency index?

CorrectNot quite: 0.875

4.[3p]
How many steps does the tree grouping bat with bird require for the same seven characters?

CorrectNot quite: 12

5.[3p]
What is long-branch attraction, and why is it worse than ordinary error?

Two fast-evolving lineages match by chance, and adding data makes parsimony more confident in the wrong tree

Correct

Long branches are harder to draw accurately

The answer is: Two fast-evolving lineages match by chance, and adding data makes parsimony more confident in the wrong tree

It makes parsimony slower to compute

The answer is: Two fast-evolving lineages match by chance, and adding data makes parsimony more confident in the wrong tree

It only affects morphological characters

The answer is: Two fast-evolving lineages match by chance, and adding data makes parsimony more confident in the wrong tree

6.[3p]
Why do sequence data test the nested hierarchy independently of anatomy?

Select all that apply

The character is a base or a residue, so there is nothing for the scorer to interpret

Correct

The tree is built by people who never examine the organism

Correct

Sequence characters were never used to build the classical arrangement

Correct

Sequence data cannot converge

The answer is: The character is a base or a residue, so there is nothing for the scorer to interpret, The tree is built by people who never examine the organism, Sequence characters were never used to build the classical arrangement

7.[2p]
Which ankle bone, pulley-shaped at both ends in artiodactyls, confirmed the molecular placement of whales? One word.

CorrectNot quite: astragalus

8.[2p]
The whale case shows that anatomical characters are unreliable and molecular ones are not.

True

The answer is: False

False

Correct

9.[3p]
Match each cause of conflict between trees to what produces it.

Convergence
Incomplete lineage sorting
Horizontal gene transfer
Long-branch attraction

the same pressure shaping unrelated lineages
an ancestral polymorphism sorted differently at different loci
chance matches between rapidly evolving lineages
genes moving between unrelated lineages

Show the answer

Convergence: the same pressure shaping unrelated lineages Incomplete lineage sorting: an ancestral polymorphism sorted differently at different loci Horizontal gene transfer: genes moving between unrelated lineages Long-branch attraction: chance matches between rapidly evolving lineages

1.[3p] Why can two character-defined groups never overlap partially on a branching history?

2.[2p] For twenty species there are about 2.2×1020 unrooted branching patterns. What is the exponent of ten?

3.[3p] The bat-with-mouse tree needs 8 steps for seven characters. What is its consistency index?

4.[3p] How many steps does the tree grouping bat with bird require for the same seven characters?

5.[3p] What is long-branch attraction, and why is it worse than ordinary error?

6.[3p] Why do sequence data test the nested hierarchy independently of anatomy?

7.[2p] Which ankle bone, pulley-shaped at both ends in artiodactyls, confirmed the molecular placement of whales? One word.

8.[2p] The whale case shows that anatomical characters are unreliable and molecular ones are not.

9.[3p] Match each cause of conflict between trees to what produces it.

1.[3p]
Why can two character-defined groups never overlap partially on a branching history?

2.[2p]
For twenty species there are about $2.2 \times 10^{20}$ unrooted branching patterns. What is the exponent of ten?

3.[3p]
The bat-with-mouse tree needs 8 steps for seven characters. What is its consistency index?

4.[3p]
How many steps does the tree grouping bat with bird require for the same seven characters?

5.[3p]
What is long-branch attraction, and why is it worse than ordinary error?

6.[3p]
Why do sequence data test the nested hierarchy independently of anatomy?

7.[2p]
Which ankle bone, pulley-shaped at both ends in artiodactyls, confirmed the molecular placement of whales? One word.

8.[2p]
The whale case shows that anatomical characters are unreliable and molecular ones are not.

9.[3p]
Match each cause of conflict between trees to what produces it.