Classification of functional changes in dose-response between orthologous OR pairs.

<p>(A) human-chimp, (B) human-macaque, (C) chimp-macaque and (D) mouse-rat. Using both the potency (EC50) and efficacy (dynamic range) to a particular ligand, an orthologous pair is classified as either indistinguishable, hyper/hypo functional (one OR had both a lower potency and efficacy) or undefined (orthologs were significantly different but potency and efficacy did not change concordantly). Each pie chart refers to the first species in the comparison (<i>e.g.</i> (A) human is ___ to chimp). For visual explanation, see <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1002821#pgen.1002821.s008" target="_blank">Figure S8</a>.