Taster n. : One who tastes; especially, one who first tastes food or drink to ascertain its quality.

Taster n. : That in which, or by which, anything is tasted, as, a dram cup, a cheese taster, or the like.

Taster n. : One of a peculiar kind of zooids situated on the polyp-stem of certain Siphonophora. They somewhat resemble the feeding zooids, but are destitute of mouths. See Siphonophora.

Example:
Why is the gene for being a Taster is very common in the population?

Taxonomy
taster, Mukesh, food, wine taster, food taster, tastes, beverage, implements, WordNet, food tasting, Translations, Unanswered questions, Português, vinhos, 中文, Chinese, Various Artists, band.

Defination from the web:
taster n. One that tastes, especially one who samples a food or beverage for quality. Any of several devices or implements used in ... Dominant gene C for taster gene c for non taster. man who can taste PTC marries a woman who cannot taste PTC and one who can. If this happy couple ...