Pheromones is a chemical factor that triggers a social response in members of a same species. Pheromones are chemicals capable of acting outside the body of secreting individual to impact the behavior of the receiving individual. Pheromones can not only attract individuals of same species but can also act as a defense or alarm agent. Can pheromones help you fall in love? Let’s see
food trail pheromones
sex pheromones and many others that effect behaviour and physiology.
Some plants communicate using pheromones.
The term pheromone was introduced by Peter Karlson and Martin Luscher in 1959, based on the Greek word ‘pherein'(to transport) and ‘hormone’ (to stimulate). They are also classified as ecto-hormones.Pheromones have evolved in the animal phyla to signal sex and dominance status.They are also responsible for social and sexual behavior among the same species.
In mammals, these pheromones are believed to be detected primarily by the vomeronasal organ (VNO), a chemo sensory organ located at the base of the nasal septum. In humans VNO doesn’t function, however it is present in the fetus but appears to be atrophied or absent in adults. in humans the olfactory system works in receiving the pheromones.
TYPES OF PHEROMONES
Aggregation pheromones function as a part of the defense system against predators, mate selection, and overcoming hos resistance by mass attack.A group of individuals at one location is referred to as an aggregation. These aggregated groups may consist of one sex or both the sexes. Male produced sex attractants have been called aggregation pheromones, because they usually result in arrival of both the sexes at the calling site.
some species release a volatile substance when attacked by a predator that can trigger flight (in aphids) or aggression (in ants, bees, termites) in members of the same species. pheromones also exist in plants, Certain plants emit alarm pheromones when grazed by animals which results in tannin production in nearby plants making them less appetizing for the animals.
Epideictic pheromones are different from territory pheromones. it was observed that female insects while laying eggs also deposit a substance in the vicinity of the eggs signalling other female insects of the sa,e species to clutch their eggs elsewhere.
Signal pheromones cause short term changes, such as the neurotransmitter release that activates a response . For instance, GnRH molecule functions as neurotransmitters in rats to elicit lordosis behavior.
Territorial pheromones help animals mark their territory. In cats and dogs these hormones are present in the urine.This is the reason that animals pee to mark their territories.
Trail pheromones are common in social insects. A common example are ants , they mark their paths with these pheromones. These pheromones chemically are volatile hydrocarbons.
Ants lay down the initial trail of pheromones as they return to the nest for food. This trail acts as guide for other ants. The pheromones on the trail must be continuously renewed as it evaporates quickly. so the ants sustain the trail until they have finished collecting food on that trail.
In animals sex pheromones indicate the availability of female for breeding.Many insect species release pheromones to attract thae male insect. Male animals also emit pheromones that gives information about their species and genotype.
Traps containing pheromones are used in farming as pest control mechanism. In case of humans, no studies for isolating such pheromones has been successful.We know in case of humans several factors play a role in the socail behavior of humans. But we can surely say that one of them is smell.Smell or pheromones do play a role in sexual attraction.
Pheromones can increase the feeling of love or physical attraction towards an individual. We cannot completely say that pheromones are responsible for love,as human is a rather complex organisms with a more complex neurological and behavioral functions.
Some of the structures of the pheromones are given below
2 .2-methyl 4-heptanone
3.6-methyl 5-heptene- 2- one
4.4 -hydroxy 4-methyl-2-pentanone
The pheromones can have 5 to 20 carbon length with a molecular weight of 80 to 200.
ADVANTAGES OF PHEROMONES
There are many advantages to using chemical signals.
- The chemicals can transmit through darkness, around obstacles, and they are very energetically efficient.
- Pheromones are relatively cheap to biosynthesize and they can be released in a very simple manner, including the simple operation of opening a gland.
- Pheromones can last for days and be transmitted over great distances. This includes millimetres for microorganisms and kilometres for other organisms, without even altering the reception or biosynthesis.
DISADVANTAGES OF PHEROMONES
Organisms cannot quickly transmit pheromones over long distances or change from one chemical message to another.
Although slow transfer is a major disadvantage, organisms have been able to adapt to counteract it by the multiplication of glands . One example of this is the black-tailed deer.
The deer produces pheromones in at least seven different sites, including urine, feces tarsal glands, metatarsal glands, preorbital glands, forehead glands, and interdigital glands. The pheromones from each site have a different function.
Pheromones may be the reason behnd animal sex, attraction , social behavior. But I wonder if we could synthesize pheromones that bring behavioral changes in humans. We could have more kindness and empathy in thus world.
Hope you enjoyed reading this information.