Phylogenetic Relationships

Phylogenetic Trees

hypothesized evolutionary relations based on share derived traits (synapomorphies)

Derived trait

a new trait that evolved from an old trait

Phylogenetic trees give extinct groups

the same worth as living groups

How does phylogenetic trees should how groups are related?

splits in ancestral populations

True/False: Phylogenetic trees have an implied goal or hierarchy.

False

Can phylogenetic trees be biased and how?

yes, based on data included and how it is presented

Operational Taxonomic Units (OTUs)

species/groups on the tree

What are the Operational Taxonomic Units (OTUs) on this phylogenetic tree?

A, B, C, D, E (outlined in pink)

Nodes & Branches

show relationships

What are the nodes on this phylogenetic tree?

green circles

What are the branches on this phylogenetic tree?

outlined in blue

Terminal Branch

leads to Operational Taxonomic Units (OTU)

Internal Branch

lead to a node

Synapomorphy

a shared derived character; can be mapped into branches

What is the synapomorphy on this phylogenetic tree?

red line

Monophyletic Group

a single common ancestor and all descendants

What is the monophyletic group on this phylogenetic tree?

shaded in purple

Sister Taxa

the next most closely related group to monophyletic group

What is the sister taxa on this phylogenetic tree?

shaded in blue

Out Group

most distantly related of all groups

What is the out group on this phylogenetic tree?

shaded in yellow

What can be traits on a phylogenetic tree?

all of the above

Absence of a trait is not a

synapomorphy

Parsimony

the preferred explanation for patterns in the data is the simplest explanation