At some point in the past, random mutations created a variant of one receptor gene, located on the X chromosome, producing two different receptor types. (hopkinsmedicine.org)
The researchers found that each nutrition molecule made use of different receptors and common signaling pathways to accomplish this. (ahealthblog.com)
A given receptor can snag a number of different odor molecules, and a given odor molecule can latch onto several different receptors. (discovermagazine.com)