Animals and plants share a common ancestor about 2 billion years ago. While they still share some of their genes, a major part of their genomes evolved independently since then.
In the advanced online edition of Molecular Biology and Evolution, authors Maurino, et. al., explore the evolution of a family of enzymes, called 2-hydroxy acid oxidases, or 2-HAOX, that are involved in breaking down fatty acids in both plant and animals. They traced the evolution of 2-HAOX back to a common ancestor that once gave rise to these enzymes. They built a database of all known 2-HAOX sequences in plants, animals and bacteria and reconstructed phylogenetic trees; they also examined and compare the substrate specificities of different members of this family.
Their data supports the evolution of 2-HOAX from a common ancestral gene. Strikingly, the evolution of this protein family in animals mirrors that in plants, possibly because animals have to break down fatty acids ingested from plants. This provides an example of how the ancestors of plants and animals independently found identical solutions to similar evolutionary challenges.