Human beings are capable of perceiving around 10,000 different smells. However, half of the genes responsible for this olfactory capacity have been disappearing in a large part of the population during the last million years of the history of the human species. In a study published in PLoS Biology , Doron Lancet and his colleagues at the Weizmann Institute (Israel) analyzed this phenomenon by measuring the ability of different subjects to detect odors such as the scent of eucalyptus, spearmint, banana or sweat. In this way, they identified a gene, OR11H7P , associated with the perception of the smell of sweat . Specifically, this gene affects the olfactory sensitivity to the smell of isovaleric acid , a fatty acid present in human sweat and in wood vinegar.
The researchers concluded that those with a mutation that inactivated the OR11H7P gene pair were unfazed by the smell of sweat even in a crowded, closed room. In contrast, those who were especially sensitive to this unpleasant odor had at least one gene from their partner intact.