What’s the human genome for? It seems that a surprising amount of it is devoted to keeping our breath sweet.
Research conducted jointly by the University of North Carolina at Chapel Hill and Procter & Gamble (P&G) Oral Care has found that more than 9,000 genes — nearly 30 percent of the genes found in the human body — are expressed differently during the onset and healing process associated with gingivitis.
(Thanks to Razib at Gene Expression for that.)
Razib goes on to speculate that: “Perhaps then bad breath and poor oral hygiene are simply a fitness indicator, and kissing evolved as a method for humans to evaluate each other’s health as an ‘honest’ signal?”
George Orwell nailed it, as always: “It is possible to love a murderer, but it is not possible to love a person with bad breath” (in The Road to Wigan Pier somewhere).