Pheromones

BBC Radio 4 - In Our Time, Pheromones

"Pheromones can certainly evolve. They're used in pest control… one of the strange things is that the first New York State entomologist in the 1880s anticipated that pheromones would be powerful. So he watched male moths flying into his window, and people were gathering on the sidewalk and he hypothesised in the 1880s that if only we could synthesize these molecules, we could perhaps use their power to control insect pests, which were a big thing in North America.

Fast forward to the first pheromones being identified in Germany. Rapidly, people started identifying the molecules and trying them out in the field. And if you release enough of these synthetic pheromones, the males can't find the females. They don't fertilize the females. Without fertile eggs, no caterpillars, crops protected and most of the apples we buy today have had some pheromone protection... that's manipulated evolution and what we might expect if pheromones work like pesticides, that we get resistance, and so far, we haven't had any resistance... because they don't affect predators, we leave intact the spiders and predatory beetles, so you can have organic farming that works really well...

Darcin is named after Jane Austen's romantic hero, Mr. Darcy in Pride and Prejudice. And it was really inspired by the first line of the book, which I'm sure you know. It's a truth universally acknowledged that a single man in possession of a good fortune must be in want of a wife. Of course, a good fortune isn't particularly important to a female mouse. But it does appear that a single male mouse in possession of Darcin must be in want of a mate...

The giant hornet is very, very armored animal and the honey bee stings just can't penetrate it. But the honeybees form a dense ball of maybe 500 worker bees around the hornets. And they raise their temperature. And they literally cook the Hornet to death because the honey bees can sustain and stand a higher temperature than the Hornet. But the point is the honey bees get warning of the Hornets by eavesdropping on the Hornet’s own communication to its nest mates. And there are a few other cases where that happens where the pheremone of a predator is detected by the prey who then can mount a Special Defense...

Our sense of smell is very good, we're very good smellers. The problem is, there's a lot of bad science concerning human pheromones. I'm persuaded we probably do have them. But if you search for pheromones on the internet, you'll get lots of sites offering you pheromones for sale. They tend to be some steroids molecules, they’re basically made up. The same group, though that has been working on rabbit pheromones in France is also working on a possible human pheromone. So the sex hormones, we probably might have them but none properly identified.

But this group in France is looking at something different. And this is a potential memory pheromone. And it looks as though baby humans, human babies respond to secretions from the nipple around the nipple of lactating mothers, these Montgomery or areola glands, there're little bumps around the nipple, and it looks as though secretion from any mother will cause any baby to respond. And that I think, maybe the first human pheromone to be identified. The things on the internet, they could have a placebo effect, but they're not real...

One of the things that I really notice the difference in the human literature, I think there are two things. First, that many people working with human pheromones have a very different definition of pheromones to those of us who work with animals. And I think this idea of a pheromone that stimulates a very specific response is a really good one. Because actually, we can see this time and time again, in animals.

Whereas a lot of people working with human pheromones would accept any kind of response, even if it's a learned response, if it's just something that arises through cultural responses. And I think the thing we particularly have to look for in humans are those situations where it's a really reliable response, because when you see responses to the purported pheromones that have been tested, you know, some, some people respond to it. Some people don't. Well, actually, if we test any of these pheromones on my mice, I can guarantee you, they will respond. And I think that's the whole point about pheromones. It's a reliable response"