Another sign #2: A type of Sleep.
Unihemispheric and asymmetrical sleep
As salamu alaykum wa rahmatuLlah wa barakatuhu
In today’s episode of BCOA, I’m going to be talking about sleep.
Sleep is a behavior characterized by a typical body posture, both eyes’ closure, and a marked decrease of motor activity. In addition, sleep is a periodically necessary behavior and therefore, in the majority of animals, it involves the whole brain and body.
However, certain marine mammals and species of birds show a different sleep behaviour and it’s that type of sleep I’m going to be talking about today.
Many animals need sleep. But all of the threats faced by animals don't just go away when it's time to sleep so they literally need to ‘keep an eye open’ for predators and some other reasons too.
All vertebrate brains consist of two hemispheres the right and the left hemisphere.
Unihemispheric sleep is when one hemisphere is asleep while the other is completely awake while Asymmetrical sleep is when one hemisphere is asleep and the other is in lighter sleep.
In dolphins, breathing is consciously controlled under water and they must go to the surface for air every few minutes or they’ll drown — Wow.
Dolphins sleep unihemispherically, that’s one hemisphere at a time, this way they can swim, breath and sleep at the same time without drowning, with one eye and their blowhole facing the surface.
Eared seals also sleep unihemispherically, When they’re migrating at sea. They float horizontally with their nostrils above the surface, closing their upward facing eye and leaving the one in the sea open, this helps them stay alert for threats from predators — subhan’Allah
Some birds sleep asymmetrically while migrating (flying). Frigate birds, for example, while on nonstop transoceanic flights for up to ten days, either sleep with both or one hemisphere at a time while flying.
The mind blowing thing about this, is that the health of these animals, is not affected by the reduction of sleep.
***
Although unihemispheric sleep is not known to occur in humans, recent research has found that humans exhibit a similar sleeping style when they experience troubled sleep in a new location for the first time, called the "first night effect." This effect involves asymmetric dynamics between the two hemispheres: while the right hemisphere engages in normal slow-wave sleep, the left hemisphere experiences shallower sleep, suggesting that it may be staying partially alert.
Basically when you’re in an environment your brain doesn’t recognise, it stays partially awake keeping you alert. Although it’s a subtle version of unihemispheric sleep, it’s still pretty amazing.
It’s really mind blowing how Allāh created these Animals. I mean a bird flying and sleeping, that has to be the most mind blowing thing I’ve ever heard about birds.
Another really intriguing thing is the fact that dolphins can drown. They look a lot like fishes but they’re actually aquatic mammals with lungs not gills which is why they can’t breath under water — I didn’t even know that wow!
Anyway that’s it on unihemispheric and asymmetrical sleep, I hope you guys enjoyed reading <3.