Phylogenetics

Analogy

Characteristic similar between organisms due to convergent evolution, not the same evolutionary path

Ancestral

Version of a character found in older ancestors

Basal taxon

Branch on a phylogenetic tree close to the root ancestor

Binomial nomenclature

System of two-part scientific names for organisms

Branch point

Node on a phylogenetic tree where lineages split

Character

Attributes allowing differentiation from others

Character state

Different conditions of a character

Derived

Version found in more recent ancestors/descendants

Genus

Division of family in taxonomic classification

Homology

Similarity in characteristics from shared ancestry

Horizontal gene transfer (HGT)

Transfer of genes between unrelated species

Linnaeus, Carl

Taxonomist who developed hierarchical species naming

Maximum parsimony

Applying the simplest explanation with fewest steps

Monophyletic group

Organisms sharing a single ancestor

Most recent common ancestor (MCRA)

Youngest extinct common ancestor for a group

Phylogenetic tree

Diagram showing evolutionary relationships

Phylogeny

Evolutionary history and relationships of organisms

Polytomy

Branch on a phylogenetic tree with more than two groups

Root

Single ancestral lineage on a phylogenetic tree

Shared ancestral character

Characteristic shared by all organisms on a tree

Shared derived character

Characteristic shared by a specific clade

Sister taxa

Two lineages diverging from the same branch point

Systematics

Field organizing organisms based on evolutionary relationships

Taxon

Single level in the taxonomic classification system

Taxonomy

Science of classifying organisms

Web of life

Phylogenetic model incorporating effects of horizontal gene transfer