What If Humans Were Nocturnal Creatures? | Unveiled

What If Humans Were Nocturnal Creatures?

We humans typically perform most of our work during the day, under the light of the sun. But, actually, that’s not all that normal to a great number of other animals. Around 70% of all animals on Earth are most active at night instead; the clear majority. So, what if we were to join them?

This is Unveiled, and today we’re asking the extraordinary question; what if humans were nocturnal creatures?

First, it’s important to note that just because humans aren’t altogether nocturnal, that doesn’t mean we’re naturally or wholly diurnal, either. While it’s true that, in real life, human circadian rhythms do favor sleeping with the lights out, and that there are a great number of benefits to our sleeping at night… primates in general don’t have set sleep cycles. Technically, they could move into a new ecosystem and choose whichever hours worked best for them, for convenience, efficiency, safety, and evolutionary sense.

That said, it’s clear that we (as we are) descended from mostly diurnal ancestors… and that our typical “sleep at night” patterns have grown to be what’s best for us. Daylight activates chemicals in the human body that make us feel more awake, while darkness naturally lowers our blood pressure and temperature in order to prepare us for sleep. As many who’ve tried switching to night time working might testify, changing the habit of a species lifetime is no easy task. But still, had our ancient, evolutionary path taken even a slightly different direction, there’s a real chance that we may have wound up nocturnal, naturally. So how would that have looked?

In general, animals develop their bodies differently to fit with the hours of the day they spend most of their time awake. Nocturnal bodies are built to counteract the low levels of visible light during the nighttime, for example, resulting in nocturnal creatures often having larger eyes and wider pupils to capture more light. Sticking with just the eye, there’s also the Tapetum lucidum, a reflective layer in the eye of some animals, such as cats, that enables them to amplify the amount of light that enters the retina… and also causes the eye to glow in the darkness. More than just being better, though, our vision would also probably be very different. This is because it’s likely that our eyes would have evolved to have more rods in our retinas than cones, as rods pick up light sources easier while cones focus more on color. So, in just this one part of the body, it follows that if humans were nocturnal then we too would have tapetums, wide pupils, larger eyes, and a sharper (although perhaps less colorful) view of the world, via a kind of biological night vision.

A lack of light also causes some of the other senses to naturally become heightened, as well. The powers of hearing, smell, taste, and even touch can dramatically increase in creatures that have to hunt and survive at night. With vision impaired due to the darkness, some animals develop an increased sense of touch, for example, to better feel vibrations in surrounding water or through the ground; some rely most on heightened hearing to perhaps respond to an attack that they can’t actually see coming; or a better sense of smell can be used to to track predator or prey in the dark.

So, nocturnal humans would also likely have improved senses across the board. What would this actually be like? Perhaps we’d have much more mobile ears that move around our heads to track sound; or longer snouts like dogs or mice to smell much more subtle scents in the air; or fibrous skin that can feel every tiny change and movement in the wind. We might find ourselves with an incredible sense of hearing like an owl or a moth, thermal vision that allows us to see heat like some snakes can, or even over 175,000 taste buds, like the catfish does. For all of those animals, their improved senses are in some way a reaction to the lack of light they experience - and so humans would surely be no different.

This is a hypothetical scenario about more than just our physical characteristics, though. A switch to nocturnality would also affect our general behavior and even the way we run our societies. The most immediate and obvious change, were this situation to just happen suddenly, would be that humanity would now do most of its work during the night… and sleep during the day. Interestingly, this would probably result in far less artificial lighting on Earth. As it is, street lamps and the like are made to offer us the opportunity to comfortably extend our waking hours, if we choose to. But in this alternate, naturally nocturnal world, all the potential adaptations previously discussed would mean that we’d no longer need extra lighting. And, in fact, that increased lighting could actually do more harm than good. Similarly, cars probably wouldn’t have headlights anymore, as the strong beams could again be less of a help and more of a hindrance, or even a danger.

If humans were nocturnal, then, we’re imagining a version of life just slightly removed from our own, but one where instead of making the most of the day… we’d all traverse the darkened streets amid the shadows, because that’s where we’d feel most comfortable. That lowered appreciation for color would have a dramatic effect, too, though… perhaps leading us to preferred living environments that are much less vibrant. Although we wouldn’t know they were less vibrant, because we could never notice it.

The wider effects on society could be almost limitless. We’d now live most of our lives in naturally cooler, nighttime temperatures… so air conditioning would now be more about bringing down the heat during the lesser-seen day, because our tolerances will’ve swung toward colder climes. Topping up your tan would also be a thing of the past, because the vast majority of us would always be asleep when the sun is at its highest. You could substitute today’s nightlife for daylife, too, with raves and parties happening over the midday hours, and bars opening up just as the sun is rising. Shops would open their doors as the night set in; schools and offices would be full from the early hours of the evening until gone midnight.

The change would be felt by more than just us, though. We know that human society, as it is, has a massive impact on the natural world as a whole… so here the natural world would also need to absorb our living our lives at night. In many cases, this would mean now-nocturnal animals shifting the other way, to become diurnal… mostly just to avoid us. At the roots of natural history, one of the main reasons that many animals are nocturnal is because they’ve had to adapt to avoid daytime predators on the prowl, including humanity. But now, the night is where all the potential trouble would be for them… and so an upheaval of their own body clocks would be necessary. It perhaps wouldn’t be the same for all animals, though. Perhaps dogs would also convert to a nocturnal lifestyle if we did, given how closely they live with us. Traditionally useful “work animals” like horses and cows might soon be awake at night, too, due to our dependence on them… although the agricultural industries where they’re used will’ve also been flipped on their heads without sunlight, so there’s a good chance that nocturnal humans wouldn’t rely on them so much.

Elsewhere, and finally, there are a wide range of other, less common adaptations that nocturnal animals have developed that could change how we function if we had them as well. Nighttime humans might come to possess echolocation like bats, for example, where we’d effectively be using our own voices to track targets and find our way around. Many nocturnal animals expertly use the night sky to navigate, so nocturnal humans might follow suit… ditching maps and GPS for just a much improved understanding of the sky above. We might even have developed our own version of bioluminescence as a means of communication, or even of attracting a mate - not unlike fireflies, glowworms, some mushrooms, and many deep sea species.

Overall, it’s clear that this is one “what if?” scenario that has massive and wide-reaching repercussions. Physically, nocturnality could totally transform our bodies; socially, it could influence so many aspects of our lives; and generally, with our being the apex predator on Earth, such a shift could have ripple effects throughout almost every other ecosystem in the world. And that’s what would happen if humans were nocturnal creatures.