Figure 1
From: GIGA: a simple, efficient algorithm for gene tree inference in the genomic age
Decomposing a tree with a duplication event into orthologous subtrees (OS's). The example shows part of the methylene tetrahydrofolate reductase (MTHFR in human) gene family. This tree can be decomposed into OS's in two different ways: 1) the fungal MET13/met9 group remains in the same OS as its ancestors, while the MET12/met11 group founds a new OS, and 2) the MET12/met11 group remains in the same OS as its ancestors, while the MET13/met9 group founds a new OS. In both cases, the two OS's are sibling groups, because they contain genes descending from the duplication event, and in both cases the FCE of the more recent OS (the one with only genes from fungi) can be dated relative to speciation events, between the opisthokont common ancestor and the fungal common ancestor in this example. Species are abbreviated with the 5-letter UniProt code: CAEEL (C. elegans, nematode worm), CHICK (G. gallus, chicken), DANRE (D. rerio, zebrafish), DICDI (D. discoideum, cellular slime mold), HUMAN (H. sapiens, human), MOUSE (M. musculus, mouse), SCHPO (S. pombe, fission yeast), YEAST (S. cerevisiae, Baker's yeast).