Chapter 26 Phylogeny Flashcards
Phylogeny
Evolutionary history of a species or group of related species
Discipline of Systematics
Classifies organisms and determine their evolutionary relationships through a computer program
Taxonomy
Scientific discipline concerned with classifying their evolutionary relationships
Who published a system of taxonomy based on resemblance?
Cardus Linnaeus
Bionomical Nomenclature
2-part names for species and hierarchical classification
Breakdown of bionomical nomenclature
- First of the name: Genus and is capitalized
- Second of the name: Species and is italicized
Taxon
Taxonomic unit at any level of hierarchy
Phylogenetic Tree
Evolutionary history of a group of organisms that can be represented
Sister Taxa
Groups that share an immediate common ancestor
Taxonomic groups from broad to narrow
domain -> kingdom -> phylum -> class -> order -> family -> genus -> species
Homologies
Phenotypic and genetic similarities due to shared ancestry
Morphology
Organisms with similar morphology or DNA sequences are more likely to be more closely related
Homology
Similarity due to shared ancestry
Analogy
Similarity due to convergent evolution
Convergent evolution
Occurs when similar environmental pressures and natural selection produces similar (analogous) adaptations
Homoplasies
Analogous structures or molecular sequences that evolved independently
What doesn’t the phylogenetic tree show?
- not phenotypic similarities
- doesn’t indicate when evolution occured or by how much
- should not be assumed that a taxon evolved from the taxon next to it
Rooted Tree
Includes a branch to represent the last common ancestor of all taxa in the tree
Basal Taxon
Diverges early in the history of a group and originate near the common ancestor
Polytomy
A branch from which more than two groups emerge
Cladistics
Groups of organisms by a common descent
Clade
Group of species that includes an ancestral species and all to descendants
Monophyletic Clade
Clade that consists of the ancestor species and all its descendants
Paraphyletic Clade
Grouping of species that consists of an ancestral species and some, but not all of the descendants
Polyphyletic Clade
Grouping of species that includes distantly related species but doesn’t include most recent common ancestor
Shared Ancestral Character
Character that originated in an ancestor of the taxon
Shared Derived Character
Evolutionary novelty unique to a particular clade
Outgroup
Species or group of species that diverged before and are closely related to the ingroup
What are the 3 domains?
- eukarya
- bacteria
- archaea
What are the 5 kingdoms?
- Monera (prokaryotes)
- Protists
-Plantae
-Fungi
-Animalia
What is horizontal gene transfer?
Movement of genes from one genome to another
Paralogous Genes
As a result from gene duplication
Orthologous Genes
Found in a single copy in the genome and are homologous b/w species
Principle of Maximum Likelihood
States that a tree can be found that reflects the most likely sequence of evolutionary events
Maximum Parsimony
Assumes that the tree that requires the fewest evolutionary events is the most likely