Lecture 4: Phylogenies

Question 1

Four reasons to find phylogenies

Answer 1

1. Tool for making classifications
2. Context for diversity
3. Device for undestanding history
4. Document adaptation

Question 2

Reversals

Answer 2

From the derived to the ancestral; cause some members of a clade to resemble non-clade members e.g. lack of shells

Question 3

Convergences

Answer 3

Cause members of different clades to resemble each other but not their common ancestor e.g. wings

Question 4

Ancestral traits

Answer 4

Might be shared among SOME but not all descendents e.g. worms

Question 5

Parsimony

Answer 5

Assume synapomorphies&raquo_space;> other kinds of similarities (ancestral traits, reversals, convergences)
Then simple methods can be used to find the tree