2. and 3. lesson Classification Flashcards
Systematics
So systematics is a way of diversificate anaminals in a structual way, which describe the relationship between different animals
Taxonomy
Taxonomy is the part of zoology where you´re naming animals and put them into groups based on special classifications.
Taxon
A group of animals, which is somehow connected in the classification so they form a taxonomic unit.
Taxonomy ranks
Taxonomy ranks is the different classifications levels animals has to go through to find its name. Top to bottem we need at least seven ranks. A way to remeber the ranks is the saying? Keap …
The 7 different taxonomic ranks
Kingdom, Phylum, Class, Order, Family, Genus, Species.
Phylogeny
The evolutionary history of any taxon´s origin and its classification, is normally presented as a tree drawing.
Monophyly (subcategory of Phylogeny)
A point in history, where a group of animals (taxon) all has the same common (mono) ancestor.
paraphyly (subcategory of Phylogeny)
When we have a taxon that includes the first ancestors but excludes the descendants.
Polyphyly (subcategory of Phylogeny)
This taxon is a problem, because its joining animals which doesnt have the same most commen ansetors.
fx. fish and dolphins, they both live underwater and have a tail but doesn´t have the same most recent ansector.
Cladistics
Cladistics is a more nuanced way of classify animal into different groups called clades, based on their shared common ancestor.
Crown node
The common ancestor of a crown group in the cladistic classification system
crown and stem groups, clades or taxons
Think about it like a tree, we have the stem groups in the bottom and the crown groups at the top. The stem groups are the instinct groups, the dead branches which have been fallen of the stem.
The stem node
Is the common ancestor of the stem group.
Basal node
Is the common ancestor of the total monophyletic group.
Sister group
A sister group is an extant crown group which is related to the another crown group through an earlier commen ancestor then the stem group.