Phylogenetic tree of ATP-binding cassette subfamily A (ABCA) phylogenetic tree. The ABCA evolutionary history was inferred using the Maximum Likelihood method based on the Whelan and Goldman model and conducted in MEGA5. Bootstrap values > 70% are indicated above branches. The tree is drawn to scale, with branch lengths proportional to the number of substitutions per site. Identified clades are indicated by numbers and delineated by vertical lines. To facilitate the tree description, the clades were split in “clusters” (subgroups described in more detail).