Phylogenetics 1 Flashcards
What did Linnaeus create
Linnaeus created a heirarchical system of nomenclature
Kingdom ex Animalia
Phylum ex Chordata
Class ex Mammalia
Order ex Primates
Family ex Hominidae
Genus ex Homo
Species ex Sapiens
What was Linnaeus system based on, and what are modern ones based on
- he based it on phenotypic similarity
- modern phylogenetic systematics are based more on genetics and evolutionary relationships
What is used to display phylogeny
a dendrogram, branching evolutionary tree
What are taxa
A taxon (plural taxa) is a species / group of interest
What does a dendrogram show
- The branches are joined by nodes representing common ancestors
- they show how closely things are related
What are monophyletic groups
in monophyletic groups, all taxa share a common ancestor
What are Paraphyletic groups
Paraphyletic groups exclude some descendants of the common ancestor (ex reptiles excluding birds)
What are Polyphyletic groups
Polyphyletic groups include taxa from different lineages (flying vertebrates include bats and birds)
What kinds of homologous characters are used for classification
Various homologous characteristics can be used to classify groups into clades
- morphologic
- genomic
- behavioural
what are derived characters
meanwhile derived characteristics are new characters that arise and are possessed by some groups of descendants
What is important to keep in mind when making dendrograms
Shared ancestral characters are used to classify groups, but the same set of data can lead to multiple hypotheses/trees
More data leads to better results, but generally the simplest is the best assumption
What is taxonomy
The naming of Taxa
What is the principle of Parsimony
The principle of parsimony
= the simplest explanation for something is usually the best
ex assuming since all primates have 5 fingers that the trait evolved once, not many times in each species’ lineage
