Chapter 26- Phylogeny + Tree of Life Flashcards
Phylogeny
Evo history of a species or group of related species
Systematics
is a discipline focused on classifying organisms and determing their evolutionary relationships
Binomial Nomenclature
sysetm of taxonomy
Binomal
2 part scientific name of a species
Genus
first part of the name
Taxonomic groups ranked BROAD to NARROW
Domain, kingdom, phylum, class, order, family , genus species,
Sister taxa
next to each other, share common ancestor NOT shared by another group
Homologies
Phenotypic and genetic similarities due to shared ancestry
Analogy
similarity due to convergent evolutionary
Cladistics
Organisms are grouped primarily by common ancestory
Clade
group of species that includes an ancestral species and all its descendents
3 groups
mono contains 1 group, paraphyletic contains same but not all descendents, polyphyletic includes distantly realted but NO common ancestor
Shared Ancestral Character
character that originated in an ancestor of the taxon
Shared derived character
evolutionary novelty unique to a particular clade
Maximum Parsmony
most likely to have less events
Maximum Likeloihood
the tree most likely to produce a given set of DNA data-based probability rules
Gene duplication increases….
the number of genes in the genome. providing more opportunities for evolutionary change
2 types of homologous genes
orthologus
paralogus
orthologus genes
homology is the result of a speciation event and occurs between genes found in different species
paralogus genes
the homology results from gene duplication and occurs between gene copies within a species
Molecular Clock
an apporoach used to estimate the absolute time of evolutionary change
Problems w molecular clocks (3)
molecular clocks do not run as smoothly as would be expect if mutatins were neutral
irregularities result from natural selection favoring some mutations over others
if the direction of natural selection changes repeatedly, it may average out over time, making genes more clocklike
HIV 1
most widespread strain in humans
3 domain system
Bacteria, Archea, Eukarya
