Odours which are assumed to be alluring actually being just less repellent might also apply to non-human mammals. One of the many things that I never had time to follow up was analysis of the urine of ewes as they came into oestrus - just before they ovulated the urine lost its odour (to my nose) and the levels of volatiles dropped sharply. Changes like that are guaranteed to confound any search for a chemical that signals sexual receptivity by an increase in abundance - which is the unstated assumption in most studies.
Unstated assumption #1: a chemical signal = presence of a molecule. But what it the signal is the temporary absence or suppression of a molecule?
Unstated assumption #2: a molecule associated with change in biological status is always an evolved signal. What about the case of (E)-2-nonenal, the "aging odor"? It's an unpleasant greasy/gassy smell found in people >40 years old. What's the message? Is it the same message as gray hair? Or are both just epiphenomena of changing metabolism?
Odours which are assumed to be alluring actually being just less repellent might also apply to non-human mammals. One of the many things that I never had time to follow up was analysis of the urine of ewes as they came into oestrus - just before they ovulated the urine lost its odour (to my nose) and the levels of volatiles dropped sharply. Changes like that are guaranteed to confound any search for a chemical that signals sexual receptivity by an increase in abundance - which is the unstated assumption in most studies.
Yes.
Unstated assumption #1: a chemical signal = presence of a molecule. But what it the signal is the temporary absence or suppression of a molecule?
Unstated assumption #2: a molecule associated with change in biological status is always an evolved signal. What about the case of (E)-2-nonenal, the "aging odor"? It's an unpleasant greasy/gassy smell found in people >40 years old. What's the message? Is it the same message as gray hair? Or are both just epiphenomena of changing metabolism?
And which (if either) evolved first - the presence of (E)-2-nonenal in old people, or the perception that it is unpleasant?