Popular insects that emit light are fireflies, which are known as lightning bugs. Surprisingly, they are not the only living creatures that emit light from their bodies. There are many more examples. But, are humans bioluminescent? That is the question that we want answers for.
In oceans and caves, some living creatures have adapted themselves to darkness thereby emitting light. These creatures can be described as bioluminescent.
What is Bioluminescence?
Some living organisms produce and emit light due to the chemical reaction occurring within their body. Most living organisms living in water exhibit this phenomenon. There are places sunlight cannot get to, that’s why these organisms produce their light from their body.
For instance, it is generally known that sunlight doesn’t get to the deep part of the sea. Bioluminescent creatures such as plants, bacteria, fungi, fish can be found in the depth of the sea.
But this doesn’t mean bioluminescence doesn’t occur on land. Fireflies, flow worms, and many other living organisms are examples of creatures with this uncommon attribute.
Most marine organisms emit light that is color blue and green as they are sensitive to other colors. Some special creatures emit light when necessary while others emit theirs constantly.
So, are humans bioluminescent?
This is one common question that has been on the minds of many people. That’s the purpose of this blog post; to provide clarity.
Two Japanese scientists, Daisuke Kikuchi and Masaki Kobayashi from Tohoku Institute of Technology performed an experiment to determine if humans are bioluminescent. The result showed that the human body emits light, but very little.
These two researchers used a highly sensitive imaging camera and were able to detect signs of bioluminescence in humans. At first, it was unbelievable that humans could radiate light and be bioluminescence as it wasn’t common, except for some creatures. Bioluminescence in humans was a great achievement, especially in the aspect of biology.
How was the bioluminescence experiment performed?
This was how the experiment was carried out by Daisuke Kikuchi and Masaki Kobayasi and the result;
Five males in their 20s were asked to face cameras with their bare chests in total darkness for 20 minutes every three hours. This experiment was carried out for three days from 10.00 a.m. to 10.00 p.m.
As the experiment progressed, the researchers discovered the body glow was rising and falling at 10.00 a.m and its peak at 4.00 p.m. The findings proved that light emission is dependent on body clocks, which is likely because of metabolic rhythm fluctuations during the day.
It was also discovered that, compared to the rest of the body, the face glowed more. This can be attributed to more exposure to sunlight.
Although the light that was detected was little it is significant. And since the light correlates with the body’s metabolism, this implies that some medical conditions can be detected by the use of cameras.
What is the importance of bioluminescence in nature?
Just like other phenomena, bioluminescence occurs for a reason. Without it, most living creatures will be unable to survive or exist.
Some of the functions of bioluminescence in living creatures are;
To Prevent Danger
Without the emission of light from the body of certain creatures, they won’t be able to hide from predators. When these creatures sense danger, the light they emit will enable them to see and run away from that point.
Bioluminescence helps to attract a mate during the mating period. Let’s say the light makes the living creatures noticeable thereby drawing a mate closer to them.
To Lure Prey
Some living creatures use the light they emit to bring prey closer before attacking. When the prey sees the light, it is drawn to these creatures leading to its capture and destruction.
Blue and green light travel well through the depths of the sea. Sea creatures especially make their way into their habitat when they emit light from their body. Movement is convenient with the help of bioluminescence.
Note that in other creatures, bioluminescence occurs due to chemical reactions but in humans, it occurs due to metabolic reactions. Whenever cells of the body respire, they produce free radicals that mix with protein and lipids.
When this happens, there could be an interaction with fluorophores in the body which results in the emission of light.
Now you see that it is not only fireflies and sea creatures that glow, humans, glow too. It might not be visible to the naked eye but experiments have confirmed the claim.
So, whenever someone asks “Are humans bioluminescent?” You should know how to respond.