Ch04&05.1 Flashcards
Define a phylogenetic tree
a hypothesis about evolutionary relationships
What can be flipped or rotated, still make sense, & does not change the phylogenetic tree?
Nodes
Define polytomy
When relationships among three or more groups are unresolved
Define Clade
a group of taxa that descended from a common ancestor. Clades can be nested in clades
Define Monophyletic group
a taxonomic group including all descendants of a common ancestor
Define Polyphyletic group
a taxonomic group including descendants from more than one Ancestor
Define Paraphyletic group
a taxonomic group not including all descendants of a common ancestor
Define Homologous traits
similar traits found in two or more species derived from a common ancestor
Define Analogous traits
similar traits found in two or more species derived from convergent evolution
Define Synapomorphy
a shared derived trait from a common ancestor
Define Homoplasy
repeated evolution of a trait not present in a common ancestor
Define Symplesiomorphy
A derived trait that has arisen so recently that it appears in only one of two sister taxa. Cannot be used for grouping
Define polarity
the direction of evolutionary change
Explain the principle of parsimony
The simplest solution is the preferred solution, which is the one that requires fewer steps
List thing needed to build a tree
1) Taxa of interest = our ingroup
2) An outgroup to establish character polarity
3) Characters
4) A method: parsimony
