Phylogenetics II: Interpretation and Application Flashcards
What are phylograms
Cladograms and phylograms are similar, but phylograms work to depict the amount of change
how do dendrograms and phylograms show sister taxa and ancestors
In both diagrams sister taxa/groups share an immediate common ancestor
The position along the branch represents possible ancestors
What can dendrograms do with characters
Characteristics can be mapped onto a cladograms to depict where they show up
what can neutral mutations show us
Not all characteristics evolve at the same rate. Neutral mutations accumulate in parts of the genome and can serve as a molecular clock to estimate when evolutionary events occurred.
What is Homoplasy
Homoplasy or convergence also occurs where similar characteristics evolve in distantly related taxa
Ex flippers evolving in both whales and seals
What is a phylogenetic hypothesis inferred based on
A phylogenetic hypothesis is inferred from available evidence of different homologous characters:
- Morphological
- Genomic
- Behavioural
When is Resemblence expected
Resemblence is the expectation in related animals with shared ancestral characteristics
What are derived characters
New derived characteristics appear over time and persist in subsets of the descendants = shared derived characteristics
What is character mapping
Character mapping:
mapping the emergence of shared characteristics onto the evolutionary tree based on which branches posses these traits and where they plausible would have emerged.
What can dendrograms and character mapping be used for
- to detect order of events
- ex: what was Sars covid being hosted by being used to determine when it jumped to different species
- When things occured
- the background rate of evolution in Aids showing when it jumped to humans
- detecting homoplasy
- ie convergence evolution
What kingdoms did Linnaeus have
in Linnaeus’ system everything was a plant or animal
What is the 6 kingdom view
eventually it changed to 5 or 6 kingdoms: Plants, Animals, Fungi, Protists, Bacteria, and Archaea
what is the three domain view
The 3 domain view of life divides everything into Eukaryotes, Archaea, and bacteria
What is the difficulty with all trees of life going back to prokaryotes
All systems have problems, and it is complicated further due to horizontal gene transfer, and organelles like mitochondria and chloroplasts originating from prokayotes being absorbed into other organisms.
