Figure 1From: A practical approach to phylogenomics: the phylogeny of ray-finned fish (Actinopterygii) as a case studySingle-copy genes are useful markers for phylogeny inference. Gene duplication and subsequent loss may not cause incongruence between gene tree and species tree if gene loss occurs before the first speciation event (a), or before the second speciation event (b). The only case that would cause incongruence is when the gene survived both speciation events and is asymmetrically lost in taxon 2 and taxon 3 (c).Back to article page