Systematics Flashcards
Name the schools of systematics
Taxonomy, Classification, Phylogenetics (cladistics)
Define Taxonomy
School of naming organisms
What is the school of naming organisms called?
Taxonomy
The school of grouping organisms is defined by what term?
Classification
Define Classification
School of grouping organisms.
How does one decipher the evolutionary histories of organisms?
By Phylogenetics, aka cladistics
Define Cladistics
aka phylogenetics. Phylogeny pertains to the evolutionary history of a taxonomic group of organisms
Homology example
Scales and feathers
Define Homology
Comes from the same cell types
or
The character had developed similarly in position or structure.
Which concept developed similarly?
Homology
Analogy example
Lungs and gills
Define Analogy
The parts of separate animals that FUNCTION ALIKE
What functions alike?
Analogy
What looks alike?
Homoplasy
Define homoplasy
Parts that look alike on other animals but aren’t necessarily from the same ancestor. Could be due to convergent evolution.
Examples of homoplasy
the wings of insects, birds, and bats
Define phylogenetics
The study of how organisms are related, usually shown as a cladogram/phylogeny branching diagram
Define Terminal Taxon
The taxon at the very end of a branch. The operational taxonomic units.
Define Ingroup
The terminal taxa that is typically the interested taxa.
The taxa in an ingroup are closely related. They are sister groups, and they share a common ancestor.
Define Outgroup
Taxa that establishes polarity of characters in a group. Closely related to outgroup, usually the first terminal taxon to branch off
Define Node
A point where the branch of a cladogram diverges. They represent theoretical ancestors
Define Most Recent Common Ancestor
Most recent node found at the base of any terminal taxa pair
Define Internode
The branch that is between two nodes/between a node and terminal taxon. They represent changes in character state along a lineage.
What is a Monophyletic group?
A group of taxa that includes one ancestor and all the descendants. Greatest interest groups
Define Clade
Another name for monophyletic group. Which is a branch that includes a single common ancestor and all of its descendants
What is a “Paraphyletic” group?
A group of taxa that includes some but not all descendants of one ancestor.
Antiquated names are in quotation marks.
Little interest groups
What is a group of little interest?
“Paraphyletic” group
Define sister groups
Two monophyletic groups that arose from a single ancestor, closest relative on the tree.
Define Polytomy
When a node branching off has more than two taxa at the end of the branching tree. Tri or polychotomy. Poor resolution of data is represented by a polytomy
Define apoporphy
It’s when the condition and position of a character state evolved from primitive to derived. (Scales and feathers)
Define parismony
When defining character evolution, go for the simplest solution, and the least amount of homoplasy or reversal
Define synapomorphy
An apomorphy unites a monophyletic group while excluding other taxa. Usually uniquely characterizes a given set of terminal groups
Define autapomorphies
An apomorphy occurs along a terminal internode, nowhere else
Define homoplasy
Cannot be simplified due to not having any common ancestors to connect. Character state evolved more than once
Define reversal
Converting a character state to a primitive state from a derived state.
Define Tie
Where a derived character state can be a homoplasy or reversal when using parsimony.
Typically the larger set of taxa after the first branch.
Ingroup
