Phylogenetics Flashcards
Order of Classifcation
Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species
Division
Phylum
Chordata
named after important synapomorphies, the notochord and a dorsal nerve cord
Hagfish
Part of the vertebrata subphylum but do not have vertebra
- share common ancestor with the subphylum but in their evolution they lost it - secondayr loss
Class
After subphylum
ex. mammalia
- Mammary glands - lactogenic
Hair
Middle ear Bones
No renal portal system
Eunucleated red blood cells
Complex integumentary systems
Neocortex region of the brain (sensory perception, cognition, spatial reasoning, language)
Order
Next level after class
order carnivora:
- suborders feliformia (cat-like) and caniformia (dog-like)
Family
Classifcation after order
Canidae are an example
KT or KP Extinction Event
One of the largest mass extinctions
Took out the dinasaurs and made way for the age of mammals
Genus
After Family
ex. Vulpes
part of the bionomial naming
Species
After genus
Second part of bionomial nomenclature
Also has authority - person who discovered
Character
An anatomical, physiological or molecular feature of an organism
Phylogeny
A hypothesis of ancestor descent relationships
Sister Taxa
Two species that are most related to each otehr compared to any other taxa in a tree
Nodes
represent common ancestors in the tree
Plesiomorphy
refers to the ancestral character state
Apomorphy
a chatacter state different than the ancestral state, or derived state
Synapomorphy
a derived character state that is shared by two or more taxa due to inheritcane from a common ancestor
help build tree
autapomorphy
a uniquely derived character state (only one species has the character)
Homology
Similarity in structure, function, physiology, development in different species because of common ancestry
Analogy/Homoplasy/non homology
Similar features but not because of common ancestry
Shark and Whale have fins but is homoplasy because of areverseal, whales and dolphins are mammals that reverted back to the ancestral state
Monophyletic
A group that includes all of the descendants of a common ancestor
also known as clades
Non monophyletic
Any case that doesnt include all the descents of a common ancestor
Paraphyletic
a group that includes some but not all of the decsents of a common ancestor
Polyphyletic
assemblages of taxa that have been erroneously grouped on the basis of homoplasious character
Principle of Parsiomony
Simple explanations are prefereed over more complicated ones
In trees, less evolutionary steps are better than more steops to explain relationshios
Least amount of steps is most parsimonious
Parismony method minizmes the number of evolutionary changes required to explain relationships
Outgroup
provides directionality to a tree and in cladistics defines the ancestral state
Homoplasy - Parallel Evolution
Independent evolution of the derived state
- Same derived trait but derived independtly of eachother
- same ancestral state, same derived trait
Ecotype
A population adapted to local environmental conditions
Homoplasy - Convergent Evolution
Independent evolution of the derived state
- From diff ancestral state, same derived state
Carcinization
The repeated independent evolution of the crab like body plan
Homoplasy - Secondary Loss
Reversion to the ancestral state
Polytomy
A phylogentic split into more than 2 branches (uncertainty)
