\[ **up: [[Chemical communication** ] --- # Pheromones The term ‘pheromone’ was coined in 1959, by Peter Karlson and Martin Luscher (of the Max Planck Institute for Biochemistry in [[Munich]], [[Germany]]).[^1] They argued that some molecules—[[2025-0321. 'The term pheromone was coined in 1959.'|'within the cloud of molecules produced by animals']][^2]—were different than others. > [[2025-0321. 'The term pheromone was coined in 1959.'|“Rather than just odours – a broad term for molecules that can elicit a spectrum of responses – pheromones were shaped over evolutionary time between members of the same species for a precise purpose.”]][^3] In 2010, Richard L. Doty published *[[Doty. 'The Great Pheromone Myth', 2010.|The Great Pheromone Myth]]*, in which he outlined the belief that “mammalian phermones do not exist”.[^4] Today, scientists know [[2025-0320. We know know 'pheromones are used by species all across the animal kingdom, in every habitat, and in a wide range of biological contexts'.|'pheromones are used by species all across the animal kingdom, in every habitat, and in a wide range of biological contexts']].[^5] --- ## Etymology *Pheromone* comes from rom Ancient Greek φέρω (phérō) ‘to bear’ + hormone.[^6] --- ## Definition [[2025-0321. 'Pheromones are chemical signals that meet well-established criteria.'|'Pheromones are chemical signals that meet well-established criteria.']][^7] | Box 1. | Pheromones: an operational definition. | | ------ | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | 1. | **The synthesized molecule/combination of molecules should elicit the same response as the natural stimulus in the bioassay.** This is the fundamental basis for the designation of a pheromone. | | 2. | **It should act in this way at natural concentrations.** Concentration is important. At high concentrations, spurious results may occur as non-pheromones may stimulate receptors. | | 3. | **For multicomponent pheromones, experiments should demonstrate that all compounds in the combination are necessary and sufficient to elicit the full response.** | | 4. | **Only this molecule or the proposed combination of molecules elicits the effect** (unlike other similar molecules or combinations that the animal would normally encounter). | | 5. | **There should be a credible pathway for the pheromone signal to have evolved by direct or kin selection.** In evolutionary terms, to be a signal, both the emission and reception of the pheromone signal should have evolved for a particular function. | | | source:[^8] | --- ## Types and functions of pheromones **Important note:** First up: many pheromones “[[2025-0321. 'For many hours after exposure to alarm pheromone, honeybees are more likely to attack intruders.'|have both immediate ‘releaser’ effects and longer lasting ‘primer’ effects.]]”[^9] For example: - [[2025-0321. 'For many hours after exposure to alarm pheromone, honeybees are more likely to attack intruders.'|'For many hours after exposure to alarm pheromone, honeybees are more likely to attack intruders.']][^10] (*See:* [[Honeybee#Pheromones|Honeybee pheromones]]) + [[2025-0321. '... male Agrotis moths do not respond to female sex pheromone for up to 24 hours after mating.'|'... male Agrotis moths do not respond to female sex pheromone for up to 24 hours after mating.']][^11] (*See*: [[Agrotis moth#Pheromones|Agrotis moth pheromones]]) Furthermore, some can signal and prime, e.g. - The [[Rats#Pheromones|GnRH molecule functions as a neurotransmitter in rats to elicit lordosis behaviour]]. Perhaps most importantly, [[2025-0320. Although pheromones 'elicit stereotyped behaviour' or 'physiological responses', these are 'modulated by context, time of day, and many other factors'.|although pheromones 'elicit stereotyped behaviour' or 'physiological responses', these are 'modulated by context, time of day, and many other factors'.]][^12] Factors can include [[2025-0320. Although pheromones 'elicit stereotyped behaviour' or 'physiological responses', these are 'modulated by context, time of day, and many other factors'.|’the receivers genetics, age, sex, hormonal state, dominance status, and recent experience.’]][^13] They do not, y’know, provide a superpower-level of control, etc. For example: - [[2025-0321. 'Male hamsters only respond to female pheromone if they are well fed, giving them sufficiently high blood testosterone levels in their hypothalamus.'|'Male hamsters only respond to female pheromone if they are well fed, giving them sufficiently high blood testosterone levels in their hypothalamus.']][^14] (*See:* [[Hamsters#Pheromones|Hamster pheromones]]) --- ### Three types #### (1) behavioural response: ‘releaser’ pheromones > Releaser pheromones are pheromones that cause an alteration in the behavior of the recipient.[^15] Basically, they can [[2025-0321. 'To some, releaser and signaler pheromones have been equated, although it may make more sense to speak of them as independent.'|’elicit a certain response’]].[^16] Examples: - [[2025-0320. The rabbit mammary pheromone, 2-methylbut-2-enal, triggers the 'suckling of rabbit pup'.|The rabbit mammary pheromone, 2-methylbut-2-enal, triggers the 'suckling of rabbit pup'.]][^17] + mate-attraction Generally, this type of pheromone elicits a rapid response, but isn’t long lasting.[^18] #### (2) physiological effects: ‘primer’ pheromones > Primer pheromones trigger a change of developmental events.[^19] [[2025-0321. 'Excellent examples of primer pheromones have been described for both male and female nonhuman animals. The effects are numerous.'|'Excellent examples of primer pheromones have been described for both male and female nonhuman animals. The effects are numerous.']].[^20] [[2025-0321. 'Excellent examples of primer pheromones have been described for both male and female nonhuman animals. The effects are numerous.'|’Beginning early in life, exposure to chemical signals from adults of the opposite sex typically will advance the onset of puberty, while exposure to analogous signals from the same sex will retard the onset of puberty (Bronson and Macmillan, 1983).’]][^21] [[2025-0321. 'Excellent examples of primer pheromones have been described for both male and female nonhuman animals. The effects are numerous.'|’ In many species, males that are exposed to chemical cues from novel adult females will typically exhibit a spike in luteinizing hormone (Maruniak and Bronson,1976), followed by a surge in testosterone (Wysocki et al.,1983).’]][^22] [[2025-0321. 'Excellent examples of primer pheromones have been described for both male and female nonhuman animals. The effects are numerous.'|’In some species, pregnant females exposed to pheromones of adult males that did not impregnate the females will terminate the pregnancy by reabsorbing the fetuses (Bruce, 1959).’]][^23] #### (3) short-term changes: ‘signal’ pheromones > Signal pheromones cause short-term changes, such as the neurotransmitter release that activates a response.[^24] Interestingly, Charles J. Wysocki states [[2025-0321. 'To some, releaser and signaler pheromones have been equated, although it may make more sense to speak of them as independent.'|’signaler pheromones may only provide information’]],[^25] e.g. [[2025-0321. 'To some, releaser and signaler pheromones have been equated, although it may make more sense to speak of them as independent.'|’the type of genes that one possesses … one’s dominance status within a social hierarchy … the type of food that was most recently consumed … or when and where to find food.’]][^26] --- ##### Debate re. types [[2025-0321. 'To some, releaser and signaler pheromones have been equated, although it may make more sense to speak of them as independent.'|'To some, releaser and signaler pheromones have been equated (Bronson, 1971), although it may make more sense to speak of them as independent.']][^27] --- ### Many functions #### Aggregation > Aggregation pheromones function in [[mate choice]], overcoming host resistance by mass attack, and defense against predators. A group of individuals at one location is referred to as an aggregation, whether consisting of one sex or both sexes.[^28] In insects, “only a small percentage of sex attractants are produced by males” (versus the “majority” of sex pheromones, which are “produced by the females”).[^6] #### Alarm > Some species release a volatile substance when attacked by a predator that can trigger flight (in aphids) or aggression (in [[Ants|ants]], bees, termites, and [[wasps]]) in members of the same species.[^29] - [[2025-0321. 'For many hours after exposure to alarm pheromone, honeybees are more likely to attack intruders.'|'For many hours after exposure to alarm pheromone, honeybees are more likely to attack intruders.']][^10] (*See:* [[Honeybee#Pheromones|Honeybee pheromones]]) + [[Pronghorn#Alarm pheromone|Alarm pheromone in Pronghorn (Antilocapra americana)]] #### Appeasement (Calming) - [[Mammals#Pheromones|Some mammals have calming (appeasement) pheromones]] #### Epideictic A bit like territorial pheromones, only different—an [[Insects|insect]] thing, where females place pheromones on their clutches to tell other females to lay their own elsewhere.[^30] #### Territorial Territorial markers, intended to “mark the boundaries and identity of an organism’s territory”.[^31] Like cat and dog urine. #### Trail Social [[Insects|insects]] use trail pheromones.[^32] This is how [[Ants|ants]] mark down their pathways, for example.[^33] #### Sex [[2025-0321. 'In animals, sex pheromones indicate the availability of the female for breeding. Male animals may also emit pheromones that convey information about their species and genotype.'|'In animals, sex pheromones indicate the availability of the female for breeding. Male animals may also emit pheromones that convey information about their species and genotype.']][^34] Sex pheromones may also signal information re. mating behaviours, receptivity and/or dominance.[^35] In the animal kingdom, females are often *selective* when deciding when/whom to mate, and this chemical communication plays a role in helping them find a high-quality made who “satisfies their reproductive needs”.[^35] #### Other - Nasonov pheromones (worker bees).[^36] - Royal pheromones (bees).[^37] - Necromones, given off by a deceased and decomposing organism; consisting of oleic and linoleic acids, they allow crustaceans and hexapods to identify the presence of dead conspecifics.[^38] --- ## Pheromones must be consistent [[2025-0321. 'Pheromones are the same in all sexually mature males, for example, of a species. It is the consistency in these molecules between individual males in a population which allows them to be identified as a pheromone.'|'Pheromones are the same in all sexually mature males, for example, of a species. It is the consistency in these molecules between individual males in a population which allows them to be identified as a pheromone.']][^39] [[2025-0321. 'Pheromones are the same in all sexually mature males, for example, of a species. It is the consistency in these molecules between individual males in a population which allows them to be identified as a pheromone.'|'Some males may produce more of the pheromone and thus may be more attractive to females: well-fed male voles with high testosterone levels produce more pheromone.’]][^40] ## Pheromones vs. signature mixes [[2025-0321. 'Pheromones are one kind of semiochemical, chemicals giving information. Another kind of semiochemical, signature mixtures, are the basis of individual recognition...'|'Pheromones are one kind of semiochemical, chemicals giving information. Another kind of semiochemical, signature mixtures, are the basis of individual recognition based on learning the different chemical profiles of individuals, allowing familiar and unfamiliar animals to be distinguished.']][^41] [[2025-0321. A good definition of pheromones vs signature mixtures.|'Pheromones (a molecule or defined combination of molecules) are species-wide signals which elicit innate responses.']][^42] [[2025-0321. A good definition of pheromones vs signature mixtures.|'Signature mixtures, in invertebrates and vertebrates, are variable subsets of molecules of an animal’s chemical profile which are learnt by other animals, allowing them to distinguish individuals or colonies.']][^43] Pheromones and signature mixes ought to be separated as concepts.[^44] [[2025-0321. 'Pheromones are one kind of semiochemical, chemicals giving information. Another kind of semiochemical, signature mixtures, are the basis of individual recognition...'|’It is precisely because individuals have different odour profiles that these can be learnt and used to distinguish different animals.’]][^45] [[2025-0321. Examples of signature mixes for animal recognition abound.|Examples of signature mixes for animal recognition abound.]][^46] For example: - [[Sheep#Signature mixes|Signature mixes and young recognition in sheep]] + [[Prairie vole#Signature mixes|Praire voles recognise their mate by scent]] - [[2025-0321. Examples of signature mixes for animal recognition abound.|Many species use scent to avoid close kin when choosing a mate.]][^47] + [[Hymenoptera (Order)#Signature mixes|Social insects use chemical profiles to distinguish nest-mates and non-nestmate conspecifics]] - [[House mouse#Darcin|Darcin (Mice)]] ----- ## Pheromone production [[2025-0321. 'Pheromones are typically secreted by specialized glands or tissues.'|'Pheromones are typically secreted by specialized glands or tissues.']][^48] - [[Moths#Pheromones|Female moth pheromones (abdominal)]] + [[Rodents#Pheromones|Rodent pheromone production (various skin glands + urine)]] - [[Callitrichids#Pheromones|Callitrichids produce pheromones both via urine and cutaneous secretions]] + [[Tiger moth#Pheromones|Tiger moth caterpillars sequester poisons and then metabolise them into volatile pheromones.]] > “Pheromones may also be produced by the activity of bacterial symbionts as in the case of, for example, guaiacol (2-methyoxyphenol), which affects phase-change in *Locusta migratoria*.”[^49] --- ## Which molecules evolve into pheromones? > “A very wide range of molecules are used as pheromones, covering every chemical dimension of structure, functional group, size and combination, and limited only by the range of molecules organisms can produce or obtain. This range reflects the ways that molecules evolve into pheromone signals. Any molecule can potentially evolve into a pheromone.”[^50] ### Two main evolutionary routes #### Molecular cues associated with a psychological state in the emitter > “… the first is from molecular cues associated with a physiological state in the emitter. This transition from cue to pheromone is facilitated by the broad sensitivity of olfactory systems (below). The discovery that fish female sex pheromones are hormones or chemical variations on them can be explained by an evolutionary scenario starting with ‘eavesdropping’. It starts with selection on males for sensitivity for these molecular cues leaking from females about to lay eggs. Those mutant males with more olfactory receptors for these hormones would get to the females first and their offspring would dominate subsequent generations. There would be selection on male olfactory receptors for increased specificity to reduce false alarms, and an increase in expression to raise sensitivity. In turn, females would be selected to secrete more of these molecules to function as a pheromone signal. This evolved production and reception of the signal distinguishes pheromone signals from cues (information used by the receiver but not evolved as a signal by the emitter, as in the case of mosquitoes attracted to the smells we give off just by being alive).”[^51] #### Exploitation of pre-existing sensitives in the receiver > “A second evolutionary route for pheromones is by exploitation of preexisting sensitivities in the receiver to molecules associated with other functions such as food finding. Male moth pheromones used in the final stages of courtship in many moth families tend to be similar to plant molecules that females are sensitive to for host-plant location. Males would have been selected to produce the molecules that females already detect. Now that it has evolved into a signal, females will not mate with males which do not release the correct species-specific pheromone during courtship.”[^52] --- Molecules used by a specific animal can often be made sense of by environment/habitat/habits.[^53] + [[Hyenas#Pheromones|Hyena pheromones are designed for long-lasting territory marking]] - [[2025-0321. 'During speciation, changes in sex pheromones commonly form one basis of pre-mating isolation.'|'During speciation, changes in sex pheromones commonly form one basis of pre-mating isolation.']][^54] + [[House mouse#Taxonomy|House mouse pheromones likely involved in the creation of subspecies in different zones]] --- ## Pheromone perception [[2025-0321. 'In mammals, which type of chemosensory receptors (and or) olfactory sensory neuron has been coopted to detect the pheromone depends on the molecule'.|’In mammals, which type of chemosensory receptors/olfactory sensory neuron has been coopted to detect the pheromone depends on the molecule: volatile pheromones may be detected by chemosensory neurons in either the main olfactory system or accessory olfactory system (Figure 4). Protein pheromones such as ESP1, ESP22, and darcin are likely detected exclusively by VR2 receptors of the vomeronasal system whereas sulphated steroid pheromones are detected by VR1 receptors. Important amines are detected by trace amineassociated receptors (TAARs). In mammals, many receptors have not been matched to their ligands.’]][^55] [[2025-0321. 'Some pheromones bypass the conventional chemosensory systems ... these pheromones have been called allohormone pheromones because they act like hormones outside the sender’s body.'|'Some pheromones bypass the conventional chemosensory systems and instead act on receptors on other neurons or on cells in tissues themselves. These pheromones have been called allohormone pheromones because they act like hormones outside the sender’s body.']][^56] [[2025-0321. 'Some pheromones bypass the conventional chemosensory systems ... these pheromones have been called allohormone pheromones because they act like hormones outside the sender’s body.'|’In some species, hormones or other molecules are transferred along with the male’s sperm to the female when mating, causing females to reject other males.’]][^57] - [[Red-sided garter snake#Pheromones|The red-sided garter snake uses prostaglandins in semen to make mated-with females reject other males]] --- ## Eavesdropping and deception > Broadcast signals like pheromones can be ‘eavesdropped’.[^58] - Predators can track prey pheromones.[^59] + Plants can use mimicry of pollinator pheromones to lure in pollinators.[^60] --- ## Humans pheromones? - *See:* [[Humans#(Hunting for) pheromones|Hunting for human pheromones]] ### Possible human mammary pheromone [[2025-0321. There might be a 'human mammary pheromone, suggested by the response of human babies to secretions from any lactating mother, not just their own. Babies suck in response to secretions from the areola gland around the nipple.'|There might be a 'human mammary pheromone, suggested by the response of human babies to secretions from any lactating mother, not just their own. Babies suck in response to secretions from the areola gland around the nipple.']][^61] --- ## Studying pheromones: the scientific process ### How are pheromones identified? 1. Chemical analysis. 2. [[Bioassays]]. [[2025-0320. Bioassays (repeatable experiments designed to measure biological responses) are required to back up claims re. pheromone identification.|Bioassays (repeatable experiments designed to measure biological responses) are required to back up claims re. pheromone identification.]][^62] --- ### Scientific process – History [[2025-0320. 'The challenge for scientists historically was that individual animals typically release vanishingly small micro- or pico-gram quantities of pheromones.'|'The challenge for scientists historically was that individual animals typically release vanishingly small micro- or pico-gram quantities of pheromones. … Many pheromones, perhaps most, consist of a particular combination of molecules, not a single molecule.']][^63] The science (and scientific equipment) to measure and/or analyse such tiny quantities simply wasn’t there in the past.[^64] [[2025-0320. 'The challenge for scientists historically was that individual animals typically release vanishingly small micro- or pico-gram quantities of pheromones.'|’The first identification of a pheromone was not published until 1959: it had taken Adolf Butenandt and his team 20 years and required material from half a million female silk moths.’]][^65] Today, it might take a single female moth for scientists to achieve the same outcome with modern equipment.[^66] --- ## Known pheromones (in these notes) - [[2-methylbut-2-enal (Pheromone)]] - [[Darcin]] --- ## TO-READ Leighton, D.H., and Sternberg, P.W. (2016). Mating pheromones of Nematoda: olfactory signaling with physiological consequences. Curr. Opin. Neurobiol. 38, 119–124. Liberles, S.D. (2014). Mammalian pheromones. Annu. Rev. Physiol. 76, 151–175. Logan, D.W. (2015). The complexity of pheromone-mediated behaviour in mammals. Curr. Opin. Behav. Sci. 2, 96–101. Touhara, K. (2013). Pheromone Signaling: Methods and Protocols (New York, NY: Humana Press). Wyatt, T.D. (2014). Pheromones and Animal Behavior: Chemical Signals and Signatures, 2 edn. (Cambridge: Cambridge University Press). Wyatt, T.D. (2015). The search for human pheromones: the lost decades and the necessity of returning to first principles. Proc. Biol. Sci. 282, 20142994. [^1]: ‘Pheromones are probably not why people find you attractive’, 9 May 2016, *BBC*, https://www.bbc.com/future/article/20160509-the-tantalising-truth-about-sex-pheromones. [^2]: ‘Pheromones are probably not why people find you attractive’, 9 May 2016, *BBC*, https://www.bbc.com/future/article/20160509-the-tantalising-truth-about-sex-pheromones. [^3]: ‘Pheromones are probably not why people find you attractive’, 9 May 2016, *BBC*, https://www.bbc.com/future/article/20160509-the-tantalising-truth-about-sex-pheromones. [^4]: Richard L. Doty, *[[Doty. 'The Great Pheromone Myth', 2010.|The Great Pheromone Myth]]* (John Hopkins University Press, 2010), p. ix. [^5]: Tristram D. Wyatt, ‘[[Wyatt. ‘Pheromones’, 2017.|Pheromones]]’, *Current Biology*, vol. 27, issue 15 (7 August 2017), p. R739. [^6]: ‘Pheromone’, *Wikipedia*, updated 8 November 2024, https://en.wikipedia.org/wiki/Pheromone. [^7]: Tristram D. Wyatt, ‘[[Wyatt. ‘The search for human pheromones’, 2015.|The search for human pheromones: the lost decades and the necessity of returning to first principles]]’, *Proceedings of the Royal Society B: Biological Sciences*, vol. 282, issue 1804 (7 April 2015), p. 2. [^8]: Tristram D. Wyatt, ‘[[Wyatt. ‘Pheromones’, 2017.|Pheromones]]’, *Current Biology*, vol. 27, issue 15 (7 August 2017), p. R739. [^9]: Tristram D. Wyatt, ‘[[Wyatt. ‘Pheromones’, 2017.|Pheromones]]’, *Current Biology*, vol. 27, issue 15 (7 August 2017), p. R740. [^10]: Tristram D. Wyatt, ‘[[Wyatt. ‘Pheromones’, 2017.|Pheromones]]’, *Current Biology*, vol. 27, issue 15 (7 August 2017), p. R740. [^11]: Tristram D. Wyatt, ‘[[Wyatt. ‘Pheromones’, 2017.|Pheromones]]’, *Current Biology*, vol. 27, issue 15 (7 August 2017), p. R740. [^12]: Tristram D. Wyatt, ‘[[Wyatt. ‘Pheromones’, 2017.|Pheromones]]’, *Current Biology*, vol. 27, issue 15 (7 August 2017), p. R740. [^13]: Tristram D. Wyatt, ‘[[Wyatt. ‘Pheromones’, 2017.|Pheromones]]’, *Current Biology*, vol. 27, issue 15 (7 August 2017), p. R740. [^14]: Tristram D. Wyatt, ‘[[Wyatt. ‘Pheromones’, 2017.|Pheromones]]’, *Current Biology*, vol. 27, issue 15 (7 August 2017), p. R740. [^15]: ‘Pheromone’, *Wikipedia*, updated 4 January 2025, https://en.wikipedia.org/wiki/Pheromone. [^16]: Charles J. Wysocki, ‘[[Wysocki. ‘Facts, fallacies, fears, and frustrations with human pheromones’, 2004.|Facts, fallacies, fears, and frustrations with human pheromones]]’, *The Anatomical Record*, vol. 281A, issue 1 (November 2004), p. 1202. [^17]: Tristram D. Wyatt, ‘[[Wyatt. ‘Pheromones’, 2017.|Pheromones]]’, *Current Biology*, vol. 27, issue 15 (7 August 2017), p. R740. [^18]: ‘Pheromone’, *Wikipedia*, updated 4 January 2025, https://en.wikipedia.org/wiki/Pheromone. [^19]: ‘Pheromone’, *Wikipedia*, updated 4 January 2025, https://en.wikipedia.org/wiki/Pheromone. [^20]: Charles J. Wysocki, ‘[[Wysocki. ‘Facts, fallacies, fears, and frustrations with human pheromones’, 2004.|Facts, fallacies, fears, and frustrations with human pheromones]]’, *The Anatomical Record*, vol. 281A, issue 1 (November 2004), p. 1207. [^21]: Charles J. Wysocki, ‘[[Wysocki. ‘Facts, fallacies, fears, and frustrations with human pheromones’, 2004.|Facts, fallacies, fears, and frustrations with human pheromones]]’, *The Anatomical Record*, vol. 281A, issue 1 (November 2004), p. 1207. [^22]: Charles J. Wysocki, ‘[[Wysocki. ‘Facts, fallacies, fears, and frustrations with human pheromones’, 2004.|Facts, fallacies, fears, and frustrations with human pheromones]]’, *The Anatomical Record*, vol. 281A, issue 1 (November 2004), p. 1207. [^23]: Charles J. Wysocki, ‘[[Wysocki. ‘Facts, fallacies, fears, and frustrations with human pheromones’, 2004.|Facts, fallacies, fears, and frustrations with human pheromones]]’, *The Anatomical Record*, vol. 281A, issue 1 (November 2004), p. 1207. [^24]: ‘Pheromone’, *Wikipedia*, updated 4 January 2025, https://en.wikipedia.org/wiki/Pheromone. [^25]: Charles J. Wysocki, ‘[[Wysocki. ‘Facts, fallacies, fears, and frustrations with human pheromones’, 2004.|Facts, fallacies, fears, and frustrations with human pheromones]]’, *The Anatomical Record*, vol. 281A, issue 1 (November 2004), p. 1202. [^26]: Charles J. Wysocki, ‘[[Wysocki. ‘Facts, fallacies, fears, and frustrations with human pheromones’, 2004.|Facts, fallacies, fears, and frustrations with human pheromones]]’, *The Anatomical Record*, vol. 281A, issue 1 (November 2004), p. 1202. [^27]: Charles J. Wysocki, ‘[[Wysocki. ‘Facts, fallacies, fears, and frustrations with human pheromones’, 2004.|Facts, fallacies, fears, and frustrations with human pheromones]]’, *The Anatomical Record*, vol. 281A, issue 1 (November 2004), p. 1202. [^28]: ‘Pheromone’, *Wikipedia*, updated 4 January 2025, https://en.wikipedia.org/wiki/Pheromone. [^29]: ‘Pheromone’, *Wikipedia*, updated 4 January 2025, https://en.wikipedia.org/wiki/Pheromone. [^30]: ‘Pheromone’, *Wikipedia*, updated 4 January 2025, https://en.wikipedia.org/wiki/Pheromone. [^31]: ‘Pheromone’, *Wikipedia*, updated 4 January 2025, https://en.wikipedia.org/wiki/Pheromone. [^32]: ‘Pheromone’, *Wikipedia*, updated 4 January 2025, https://en.wikipedia.org/wiki/Pheromone. [^33]: ‘Pheromone’, *Wikipedia*, updated 4 January 2025, https://en.wikipedia.org/wiki/Pheromone. [^34]: ‘Pheromone’, *Wikipedia*, updated 4 January 2025, https://en.wikipedia.org/wiki/Pheromone. [^35]: ‘Sex pheromone’, *Wikipedia*, updated 27 August 2024, https://en.wikipedia.org/wiki/Sex_pheromone. [^36]: ‘Pheromone’, *Wikipedia*, updated 4 January 2025, https://en.wikipedia.org/wiki/Pheromone. [^37]: ‘Pheromone’, *Wikipedia*, updated 4 January 2025, https://en.wikipedia.org/wiki/Pheromone. [^38]: ‘Pheromone’, *Wikipedia*, updated 4 January 2025, https://en.wikipedia.org/wiki/Pheromone.‘Pheromones are probably not why people find you attractive’, 9 May 2016, *BBC*, https://www.bbc.com/future/article/20160509-the-tantalising-truth-about-sex-pheromones. [^39]: Tristram D. Wyatt, ‘[[Wyatt. ‘Pheromones’, 2017.|Pheromones]]’, *Current Biology*, vol. 27, issue 15 (7 August 2017), p. R740. [^40]: Tristram D. Wyatt, ‘[[Wyatt. ‘Pheromones’, 2017.|Pheromones]]’, *Current Biology*, vol. 27, issue 15 (7 August 2017), p. R740. [^41]: Tristram D. Wyatt, ‘[[Wyatt. ‘Pheromones’, 2017.|Pheromones]]’, *Current Biology*, vol. 27, issue 15 (7 August 2017), p. R740. [^42]: Tristram D. Wyatt, ‘[[Wyatt. ‘Pheromones and signature mixtures’, 2010.|Pheromones and signature mixtures: defining species-wide signals and variable cues for identity in both invertebrates and vertebrates]]’, *Journal of Comparative Physiology A*, vol. 196 (2010), p. 685. [^43]: Tristram D. Wyatt, ‘[[Wyatt. ‘Pheromones and signature mixtures’, 2010.|Pheromones and signature mixtures: defining species-wide signals and variable cues for identity in both invertebrates and vertebrates]]’, *Journal of Comparative Physiology A*, vol. 196 (2010), p. 685. [^44]: Tristram D. Wyatt, ‘[[Wyatt. ‘Pheromones’, 2017.|Pheromones]]’, *Current Biology*, vol. 27, issue 15 (7 August 2017), p. R740. [^45]: Tristram D. Wyatt, ‘[[Wyatt. ‘Pheromones’, 2017.|Pheromones]]’, *Current Biology*, vol. 27, issue 15 (7 August 2017), p. R740. [^46]: Tristram D. Wyatt, ‘[[Wyatt. ‘Pheromones’, 2017.|Pheromones]]’, *Current Biology*, vol. 27, issue 15 (7 August 2017), p. R740. [^47]: Tristram D. Wyatt, ‘[[Wyatt. ‘Pheromones’, 2017.|Pheromones]]’, *Current Biology*, vol. 27, issue 15 (7 August 2017), p. R740. [^48]: Tristram D. Wyatt, ‘[[Wyatt. ‘Pheromones’, 2017.|Pheromones]]’, *Current Biology*, vol. 27, issue 15 (7 August 2017), p. R741. [^49]: Tristram D. Wyatt, ‘[[Wyatt. ‘Pheromones’, 2017.|Pheromones]]’, *Current Biology*, vol. 27, issue 15 (7 August 2017), p. R741. [^50]: Tristram D. Wyatt, ‘[[Wyatt. ‘Pheromones’, 2017.|Pheromones]]’, *Current Biology*, vol. 27, issue 15 (7 August 2017), p. R741. [^51]: Tristram D. Wyatt, ‘[[Wyatt. ‘Pheromones’, 2017.|Pheromones]]’, *Current Biology*, vol. 27, issue 15 (7 August 2017), p. R741. [^52]: Tristram D. Wyatt, ‘[[Wyatt. ‘Pheromones’, 2017.|Pheromones]]’, *Current Biology*, vol. 27, issue 15 (7 August 2017), p. R741. [^53]: Tristram D. Wyatt, ‘[[Wyatt. ‘Pheromones’, 2017.|Pheromones]]’, *Current Biology*, vol. 27, issue 15 (7 August 2017), p. R741. [^54]: Tristram D. Wyatt, ‘[[Wyatt. ‘Pheromones’, 2017.|Pheromones]]’, *Current Biology*, vol. 27, issue 15 (7 August 2017), p. R742. [^55]: Tristram D. Wyatt, ‘[[Wyatt. ‘Pheromones’, 2017.|Pheromones]]’, *Current Biology*, vol. 27, issue 15 (7 August 2017), p. R742. [^56]: Tristram D. Wyatt, ‘[[Wyatt. ‘Pheromones’, 2017.|Pheromones]]’, *Current Biology*, vol. 27, issue 15 (7 August 2017), p. R743. [^57]: Tristram D. Wyatt, ‘[[Wyatt. ‘Pheromones’, 2017.|Pheromones]]’, *Current Biology*, vol. 27, issue 15 (7 August 2017), p. R743. [^58]: Tristram D. Wyatt, ‘[[Wyatt. ‘Pheromones’, 2017.|Pheromones]]’, *Current Biology*, vol. 27, issue 15 (7 August 2017), p. R743. [^59]: Tristram D. Wyatt, ‘[[Wyatt. ‘Pheromones’, 2017.|Pheromones]]’, *Current Biology*, vol. 27, issue 15 (7 August 2017), p. R743. [^60]: Tristram D. Wyatt, ‘[[Wyatt. ‘Pheromones’, 2017.|Pheromones]]’, *Current Biology*, vol. 27, issue 15 (7 August 2017), p. R743. [^61]: Tristram D. Wyatt, ‘[[Wyatt. ‘Pheromones’, 2017.|Pheromones]]’, *Current Biology*, vol. 27, issue 15 (7 August 2017), p. R743. [^62]: Tristram D. Wyatt, ‘[[Wyatt. ‘Pheromones’, 2017.|Pheromones]]’, *Current Biology*, vol. 27, issue 15 (7 August 2017), p. R739. [^63]: Tristram D. Wyatt, ‘[[Wyatt. ‘Pheromones’, 2017.|Pheromones]]’, *Current Biology*, vol. 27, issue 15 (7 August 2017), p. R739. [^64]: Tristram D. Wyatt, ‘[[Wyatt. ‘Pheromones’, 2017.|Pheromones]]’, *Current Biology*, vol. 27, issue 15 (7 August 2017), p. R739. [^65]: Tristram D. Wyatt, ‘[[Wyatt. ‘Pheromones’, 2017.|Pheromones]]’, *Current Biology*, vol. 27, issue 15 (7 August 2017), p. R739. [^66]: Tristram D. Wyatt, ‘[[Wyatt. ‘Pheromones’, 2017.|Pheromones]]’, *Current Biology*, vol. 27, issue 15 (7 August 2017), p. R739.