Ancestral State Reconstruction & Ulwazi Discussion

Question 1

How does ancestral state reconstruction link yo what we’re doing? (2)

Answer 1

• Sheds light into possible drivers of speciation.

• Helps us understand how things/states came to be & what evolutionary processes might have caused them.

Question 2

Where do we start?

Answer 2

Start from ancestor to tips (explain history until now, currently).

Question 3

Phrase to use when explaining?

Answer 3

“Maintained the ancestral state”

Question 4

Things to look for for Ancestral state reconstruction? (4)

Answer 4

● What was the ancestral state.

● Maintenance of the ancestral state vs the Change relative to ancestral state.

● Secondary shift to the ancestral state (so from completely black to white with no maintenance).

● Where you see sister taxa doing the opposite thing (having different states).

●

Question 5

Tips to answering questions on Tree topology & tree incongruence? (6)

Answer 5

• Topology means nothing if there’s no statistical support.

• Use the nodal support, NOT the topology of the tree.

• “It is congruent at this point…, but is incongruent at this point…”

• If node is supported & trees look the same = congruent.

• If node is supported & trees look different = incongruent.

• If node is not supported & trees look different = congruent at this point & so on.

Question 6

mtDNA attributes? (2)

Answer 6

• Fast evolving.
• More structured.

Question 7

mtDNA vs rRNA vs nDNA in terms if evolving rate?

Answer 7

● mtDNA
= fast evolving.

● nDNA
= moderate evolving.

● rRNA
= slow evolving.

Question 8

Character displacement vs Character release?

Answer 8

● Character displacement
= caused by interspecific competition.

● Character release
= lack of competition.

Question 9

Phylogenetic tree: P. semivariegatus attributes? (3)

Answer 9

• Described as different species.
• When naming go with the one discovered first.
• P. punctatus made P. semivariegatus paraphyletic.

Question 10

Taxonomist solutions to P. semivariegatus problem? (2)

Answer 10

● To fix the paraphyletic problem
= change the genus name of the one making them paraphyletic.

● To fix the monophyly problem
= separate the clades via changing genus names.

Question 11

Thing to note about NJ phylogenetic inference?

Answer 11

Reduces branch lengths.