Phylogenetics Flashcards
What is phylogeny?
A hypothesis describing the history of descent of a group of organisms from their common ancestor
What does a phylogenetic tree represent?
Depicts the evolutionary descent from a common ancestor
What is a clade?
Monophyletic group that is usually branched that contains a single ancestor and it’s descendants
What is the difference between a branch and a node of a phylogenetic tree?
A branch is a lineage through time; a node is where a lineage splits into two independent lineages
How can you tell which species will have accumulated the least genetic differences using a phylogenetic tree?
whichever species have the most recent common ancestor have accumulated the least genetic differences
What does monophyletic mean?
one common ancestor and all of its descendents
What does paraphyletic mean?
one common ancestor and some of its descendents
What does polyphyletic mean?
a grouping with no recent common ancestor
What is the difference between an ingroup and an outgroup?
the outgroup is a lineage that is closely related to an ingroup (which is the lineage we are interested in) but has branched off below the base of the ingroup on the evolutionary tree
What are ancestral traits? Are they found in ingroups or outgroups?
shared traits that are inherited from a common ancestor
found in both ingroups and outgroups
What are derived traits? Are they found in ingroups or outgroups?
differs from the ancestral form and it arose somewhere on that lineage and was not inherited, only in ingroups
What are some practical applications of having phylogenetic trees that show the evolutionary relatedness?
social justice and pathogen outbreaks
What are phylogenetic classifications?
classifications based on evolutionary relationships of species
What can complicate evolutionary relationships? Why?
convergent evolution, because it can mimic shared ancestry
What is a molecular clock?
A mechanism to estimate the timeline of evolution based on constant rates of change in certain genes
