2 Flashcards
Paraphyletic clade?
An ancestor and a group of oof taxa but it is not monophyletic because some of the descendants are missing.
Each row in a character matrix is a?
Taxon
The characters (columns) in a character matrix are?
Traits
Outgroups in a character matrix have __ for all characters?
0’s
How to construct a tree from character matrix?
- Outgroup
- Identify two taxa that share most derived characters (sister taxa)
- Synapomorphies
- Identify taxon that shares the most derived characters with sister taxa
- Synapomorphies
Tree to indented classification?
Each time there is an indent, it is a new taxa from earliest to latest speciation event. Always group first, then traits.
- Outgroup
- Synapomorphy
- Outgroup of monophyletic clade
- Synapomorphy
- Group 1 of monophyletic clade
- Group 2 of monophyletic clade
Tree from parentheses representation?
(Latest group, (Later group, (Earliest group 1, group 2)))
Why a phylogenetic tree a hypothesis?
It is based on data.
Tree thinking?
Using data to construct phylogenetic trees and reading phylogenetic trees to determine evolutionary relationships. It can also allow you to understand how different features or traits evolve in different groups.
Pedigree?
Nodes are named people instead of common ancestors since a pedigree is the ancestors of individuals whereas a phylogeny represents the ancestors of populations or species.
How many ancestors are in a pedigree vs a phylogeny?
Two ancestors for pedigree, one for phylogeny.
In a phylogeny, how many direct descendants do you have, always?
Two with each node having one direct ancestor.
Polytomy?
Phylogenetic tree with multiple branches coming from a node.
How does a polytomy happen?
we don’t know how several groups are related since we don’t know their Synapomorphies uniting them. Thus, polytomy showcases a lack of information.
Tetrapods?
All have the same forelimbs
