Why is it you can smell sulphur but you can’t smell nitrogen or oxygen?
And why does the air around some hot appliances have a distinctive odour. I can smell that my clothes iron is hot.
In: Chemistry
Nature has sculpted all living things through evolution for billions of years. Species tend to evolve ways to avoid deadly gasses. Sulfur for instance is highly toxic. We would want to be instinctually repulsed by that odor, otherwise our natural curiosity may end up killing us. I imagine the reason there are noxious gasses that are odorless is because they have become prevalent only in recent times. I’m pretty sure carbon monoxide isn’t a major threat in nature (if it is, maybe the native life would develop a method to detect it ). I would say it’s why lots of toxic foods and like, poop for example smells like, well, shit. When food rots, we are repulsed by it. Cats hate citrus and it happens to be toxic to them I believe.
Anyway I have no idea the bio-mechanism behind the actual detection of these molecules but I think we need specific receptors and also a brain designed to process the varying signals properly
Edit: typos
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