Figure 19.4: Lateral Gene Transfer Complicates Phylogenetic Relationships (A) The phylogeny of four hypothetical prokaryote species, two of which have been involved in a lateral transfer of gene x. (B) A tree based only on gene x shows the phylogeny of the laterally transferred gene, rather than the organismal phylogeny. (C) In many cases, a consensus tree based on a “stable core” of genes accurately reflects the organismal phylogeny.