Must we stop and smell the flowers?

Apart from passive receptivity, I have had no more opportunity to experience perfumes than any other nose in the average crowd. And even in that chaos, the scents seem to be equally admixed with whatever else clings to us -not all of it encouraging. But I have to believe that the ability to notice different smells, let alone be repulsed or attracted to them, must serve more purpose than merely warning us off things that might be harmful. Why dedicate an entire organ just to avoid rotting carcasses or to pick pleasing flowers -as socially useful as that might be?

Indeed there may be an entire chemical vocabulary entrusted to smells, that enriches the umwelt of the otherwise utilitarian world of the animal kingdom. Given our common origins, why would we be any different?

Of course, except for their behaviour, animals are unable to communicate what they are reading in the odour, and until the very recent identification of olfactory receptor genes, even variations in humans were, by and large, a mystery. And yet, their importance is signalled by the finding that these genes appear to constitute the largest gene family in all the mammalian genomes.

The problem, perhaps, has always been in the attribution. As with animals, if we don’t know that odours are responsible for an action, we wouldn’t think to credit them. If a dog, for example, marks a spot after smelling it, we have no idea what that means. Does it merely suggest that the dog simply likes whatever it was it smelled, or something more? Is the dog leaving a message other than ‘I was here, too’?

You see the difficulty: an odour may engender an action, but neither the signal nor the response can be reliably categorized as anything other than a generic stimulus/response. And given the size of the olfactory receptor gene family, a purposeless, or motiveless reflexive response seems unlikely.

So, how have we made use of this prowess historically? Well, for one thing, we have used odours, to mask odours -a rather recursive, circular activity, it seems. The fact that bathing, at one time was frowned upon -or perhaps difficult to achieve with any regularity for other than the wealthy- usually demanded olfactory disguise amongst those not similarly handicapped. The need to remedy the resultant smell, in itself suggests a nascent awareness of a message, camouflaged as it might be in societal norms.

And, think of the now discredited Miasma theory: that many diseases -the Bubonic Plague springs to mind- were caused by ‘bad air’: smells, in other words. One can certainly understand the conflation of the odour of, say, rotting meat and sickness that might follow ignoring the message inherent in its telltale reek, with the idea that the smell itself might be the cause. Only when germs were identified, and -in the absence of germs- not the air around them, did the idea of smell become merely an indicator, not a cause of disease.

But there’s a hint of a more useful and atavistic function of odours in the discovery of its importance in the initial bonding and identification of human mothers with their newly born offspring. I suppose it should have been obvious for millennia, though: an orphan lamb is often rejected by an unrelated lactating mother unless the strange lamb is made to smell like her.

So, where am I going with this? Well, first of all, the findings of a recent study [lead author Casey Trimmer, PhD] published online in advance of print in the Proceedings of the National Academies of Sciences: https://www.sciencedaily.com/releases/2019/04/190430164208.htm

‘Humans have about 400 different types of specialized sensor proteins, known as olfactory receptors, in their noses. One odor molecule can activate several different olfactory receptors, while any given receptor can be activated by several different odor molecules. In a process that remains to be decrypted, the olfactory system somehow interprets these receptor activation patterns to recognize the presence, quality (does it smell like cherry or smoke?) and intensity of millions, maybe even trillions, of different smells… Small differences in olfactory receptor genes, which are extremely common in humans, can affect the way each receptor functions. These genetic differences mean that when two people smell the same molecule, one person may detect a floral odor while another smells nothing at all… Because most odors activate several receptors, many scientists thought that losing one receptor wouldn’t make a difference in how we perceive that odor. Instead, our work shows that is not the case…  A change in a single receptor was often sufficient to affect a person’s odor perception… olfactory receptors in the nose encode information about the properties of odors even before that information reaches the brain.’

Why the receptor complexity if odours are mainly simple social adjuncts? Or, is there more going on than meets the nose? Obviously we seem to have less appreciation of the panoply of chemicals around us than, say, the average dog, but because we do not ‘smell’ them with equal facility, does that mean they have less of an effect on us? As we have begun to appreciate in terms of mother/infant recognition, not all odours reach conscious awareness. Not all smells are nameable.

Some perfume manufacturers maintain that their products contain pheromones (chemical signals) which might activate aphrodisiac-like behaviour in humans, but so far the evidence is tenuous, to say the least. Given our common evolutionary history with animals who do produce and react to pheromones, and our own incredible biological investment in olfactory receptors, however, I suspect it is just a matter of time before similar chemicals and effects are identified and utilized in us.

What brought this whole subject to mind, though, was a titillating article in the Smithsonian Magazine about Cleopatra’s perfume: https://www.smithsonianmag.com/smart-news/may-be-what-cleopatra-smelled-180972854/

‘Back in 2012, the archaeologists uncovered what was believed to be the home of a perfume merchant, which included an area for manufacturing some sort of liquid as well as amphora and glass bottles with residue in them… The researchers took their findings to two experts on Egyptian perfume, Dora Goldsmith and Sean Coughlin, who helped to recreate the scents following formulas found in ancient Greek texts.’

And, no, there’s no proof that what was recreated was what Cleopatra used -in fact, ‘It’s believed she had her own perfume factory and created signature scents instead of wearing what would be the relative equivalent of putting on a store-bought brand.’ But still, it’s a smell that Cleopatra might have worn…

There’s a legend that she believed so fervently in her perfume’s allure that she soaked the sails of her royal ship in it – so much, in fact, that Marc Antony could smell her coming all the way from shore when she visited him at Tarsus.

There’s got to be something in that: where there’s smoke there’s fire, eh?