NB! This dictionary is under construction

Orthology analysis

Two genes related through a speciation, orthologs, are more likely to have the same function than are two genes originating from a duplication, paralogs. This is because natural selection usually limits the mutational evolution of genes, which may potentially allow the acquisition of new functions, but most often are deleterious for the genes original function. After a duplication, however, there is an extra gene copy that can be mutated without compromising the original function. Consequently, since paralogs are more likely to have evolved different functions, the identification of orthologous genes in other organisms, typically model organisms, provide a good predictor of function of a gene of interest i, e.g., the human genome.

Reconciliation, reconciled tree

A reconciled tree describes a gene tree's, G, evolution inside a species tree, S, marking genetree vertices as speciations (occurring on vertices of S) or duplications (occurring on edges of S; losses are implicit). Formally a reconciled tree is a pair (G, γ) of a gene tree G and a reconciliation γ, which is a function mapping vertices of the implicit species tree S to sets of vertices in G. A graphic representation of a reconciled tree is shown below; the thick line indicates the mapping γ(x) = {u,v,w}.