With nearly a million variations on 400 smell receptors,
everyone senses smell differently
A difference at the smallest level of DNA -- one amino acid
on one gene -- can determine whether you
find a given smell pleasant. A different amino acid on the same gene in your
friend's body could mean he finds the same odor offensive, according to researchers
at Duke University.
There are about 400 genes coding for the receptors in our
noses, and according to the 1000 Genomes Project, there are more than 900,000
variations of those genes. These receptors control the sensors that determine
how we smell odors. A given odor will activate a suite of receptors in the
nose, creating a specific signal for the brain.