10.3 Phylogeny Flashcards
Defintion of phylogeny
The grouping of organisms based on their evolutionary relationships using common ancestry
What is phylogenetics?
The study of the evolutionary history of groups of organisms, and how closely related they are to one another
What does phylogeny tell us?
Which group a particular organism is related to, and how closely related these organisms are
What is a phylogenetic tree?
A diagram showing the evolutionary history of groups of organisms. They are branched, which shows which groups have evolved from a common ancestor
What are the advantages of phylogenetic classification over hierarchy classification?
-Phylogenetic classification connects groups based on their evolutionary relationships rather than their characteristics
-Phylogeny produces a continuum rather then discrete groups
-Phylogeny gives a better description of variety present within groups, rather than giving the impression all groups are equal it age. It shows change over time
What is the relationship between phylogeny and classification?
Classification uses the knowledge of phylogeny in order to confirm the classification groups are correct or causes them to be changed
How do you interpret a phylogenetic tree?
-tips represent groups of descendant groups (often species)
-nodes on the tree (where new lines branch off) represent the common ancestors of them descendants
-two descendants that split from the same tree are called sister groups
-the closer the branches, the closer the evolutionary relationships
-present organisms at the top
What are more techniques for classifying organisms based on evolutionary relationships?
- Compare the base sequence of DNA or mRNA - the higher the percentage of similarity in the order of the base sequent the more closely related they are
- Compare the amino acid sequence - specific proteins will be found in different species
- Immunological comparison - similar proteins should bind to similar antibodies
