Male vs Female

 

Insects are not like people, because they have antennae instead of noses, and because they use pheromones and we don't. Still, it's always good to remember that when it comes to the chemosensory world, there's always a difference between males and females:

The differing olfactory worlds of female and male silk moths

Jan 2024, phys.org

https://phys.org/news/2024-01-differing-olfactory-worlds-female-male.html

Male moths live in a completely different olfactory world to their female counterparts. For example, the antennae of male silk moths are highly specialized to detect female sex pheromones like bombykol and bombykal, while females cannot even smell their own pheromones.

Bombykol attracts and bombykal deters, for males.

For females, they can't smell any of that. Instead they smell isovaleric acid and benzaldehyde, which are in silkworm feces, which can be found on mulberry trees, since they are the only trees where silk worms live, and they're also where silk moths want to lay eggs.

via Max Planck Institute for Chemical Ecology and Martin Luther University Halle-Wittenberg: Females smell differently: characteristics and significance of the most common olfactory sensilla of female silkmoths, Proceedings of the Royal Society B: Biological Sciences (2024). DOI: 10.1098/rspb.2023.2578

https://dx.doi.org/10.1098/rspb.2023.2578

Image credit: AI Art - Adam and Eve According to the Bible - 2025

Study suggests an 'odor sensor' may explain male and female differences in blood pressure

Mar 2024, phys.org

https://medicalxpress.com/news/2024-03-odor-sensor-male-female-differences.html

Blood pressure in premenopausal human and mouse females is typically 10 points lower in both diastolic and systolic pressure than in males. Some studies suggest the difference may be caused by sex hormones, but the biological basis for the variation is not entirely clear.

Olfactory receptors are found all over the body, in lots of places that are not only in our nose, like in our kidneys for example (and on the surface of our skin but I don't have the science for that, only personal experience). Anyway, they've now found an olfactory receptor lining blood vessel walls of a part of the kidney that releases a blood pressure hormone called renin. 

Olfacotry receptors each have their own gene, so it's easy to look at a population and select people with mutations of this gene, which they did. These people, women, who didn't have the gene also had blood pressure levels just like men. 

via Johns Hopkins University School of Medicine and Queen Mary University of London: Jiaojiao Xu et al, An Evolutionarily Conserved Olfactory Receptor is Required for Sex Differences in Blood Pressure, Science Advances (2024). DOI: 10.1126/sciadv.adk1487.

https://dx.doi.org/10.1126/sciadv.adk1487

Gene Editing for Behavior Design

Illustrated by Bill Butcher for The Economist

Because ants are social creatures, an ant colony is really a superorganism, making them a valuable model for studying complex biological systems. And because of the way they reproduce, scientists can edit whole colonies in one stroke.

Although ants have 350 odor receptor genes (similar to humans), they also have this thing called a coreceptor gene that every odor gene has to go through to work. Shut that one off, and you shut down the whole system.

And what happens when ants can't smell? They stop talking to other ants, stop doing their job, and they get lost from the group. That's not it though, they also saw changes in brain anatomy, where some sensory substructures didn't grow at all.

Scientists are hoping these studies can help understand how social behavior changes the way neurological disorders like schizophrenia or depression work, and how sensory development in general change the brain.

***
Now, as I stretch on a heavy tangent here, I think about how there are developers on the other side of candy crush and facebook whose job it is to model your behavior and then tweak it to make you stay using the product. Game theory maybe, the science of addiction perhaps? Behavior design, according to this article (an earlier attempt termed it captology). Not sure what we're calling this, but everything from dating websites to the weather channel are using these techniques to keep us tapping into the pleasure centers of our brains and therefore coming back for more. In a distant future, I wonder if we might want to try knocking out the olfactory receptors in people in order to make them more malleable. If we take away people's sense of smell, maybe they will be more easily influenced to do what we want them to do.


Researchers use CRISPR to manipulate social behavior in ants
Aug 2017, phys.org

From two different studies:
Cell, Trible et al: "orco mutagenesis causes loss of antennal lobe glomeruli and impaired social behavior in ants."www.cell.com/cell/fulltext/S0092-8674(17)30772-9 , DOI: 10.1016/j.cell.2017.07.001

Cell, Yan et al: "An engineered orco mutation produces aberrant social behavior and defective neural development in ants"www.cell.com/cell/fulltext/S0092-8674(17)30770-5 , DOI: 10.1016/j.cell.2017.06.051


Post Script:
The Scientists Who Make Apps Addictive, Ian Leslie, Nov 2016, The Economist

good explanation of behavior design in computer programming/software development:

When you get to the end of an episode of “House of Cards” on Netflix, the next episode plays automatically unless you tell it to stop. Your motivation is high, because the last episode has left you eager to know what will happen and you are mentally immersed in the world of the show. The level of difficulty is reduced to zero. Actually, less than zero: it is harder to stop than to carry on. Working on the same principle, the British government now “nudges” people into enrolling into workplace pension schemes, by making it the default option rather than presenting it as a choice.

When motivation is high enough, or a task easy enough, people become responsive to triggers such as the vibration of a phone, Facebook’s red dot, the email from the fashion store featuring a time-limited offer on jumpsuits. The trigger, if it is well designed (or “hot”), finds you at exactly the moment you are most eager to take the action. The most important nine words in behaviour design, says Fogg, are, “Put hot triggers in the path of motivated people.”

...
Unconscious impulses are transformed into social obligations, which compel attention, which is sold for cash.

see also: Addiction by Design, by Natasha Dow Schüll, Princeton 2013

On Space and Place

Confused John Travolta

The hypothalamus is called the seat of social behavior. The hippocampus is the thing that knows where you are, your internal GPS. Together, these brain parts, along with your olfactory system, of course, influence all of your decisions. Everything we do is dependent on where we are (or where we think we are) and who we’re with (or who we think…). Olfactory data informs these things. Places and the smell of those places are centrally located both in the memory and in the motivating, motility actuating parts of us. The emotions that drive us are informed by the smells of the places we are in.

This new report shows that there may be very specific cells that can tell who’s house you’re in. (The experiment is on male mice and other male’s habitats.) They’re looking to use this to help people with social disorders, like autism, schizophrenia, depression, and social anxiety. Anyway, this just points to the use of olfactory studies to help with larger social problems.

Smell tells intruder mice how to behave

phys.org, Jun 2016