SNAKE DETECTION HYPOTHESIS- OUR LESSER KNOWN “SUPER-POWER” OF DETECTING SNAKES!

WHERE IT ALL BEGAN 

In the year 2016, Nagoya University in Japan performed a simple experiment to test out what animal would a human being be able to differentiate from the other ones. 

The twist is that the animals were presented as blurred-out photos of the same. initial one 65% blurred 40% blurred 0% blurred They recruited about 20 students or volunteers and showed them blurry pictures of 4 different animals, cats, birds, fish, and snakes. 

At first, all the photos were too blurry to differentiate any of the following but then they gradually started reducing the blur of photos and asked students to tell when they can differentiate any.

The graph shows how students could consistently able to identify the snake image, and this wasn’t a surprise to the researchers as the idea they were researching on was known as the SNAKE DETECTION HYPOTHESIS.

To access Nagoya University’s research – click here.

THE SNAKE DETECTION HYPOTHESIS 

It proposes how primates have the ability to quickly spot and avoid a snake deeply embedded in them. This was due to an evolutionary consequence of the danger snakes put forward to us. 

And this test was only one of the tests conducted to support the hypothesis. 

Some researchers claim that this is due to the elements of the primate brain and the visual system evolved in terms of anti-snake adaptations. 

THE RECENT TWIST 

Recently, it has been proposed that while snakes might have shaped us in our evolution, in some cases, even we might have shaped aspects of their evolution too. Researchers have found patterns to call that we generally are a bit touchy and innate about the snakes, and we are really good at detecting them, the size and how much threat they propose to us, all of these maybe for good evolutionary measures.

DATES BACK…

Around 60 million years ago, during the cretaceous period, the asteroids, volcanoes, and whatnot. The non-avian dinosaurs faced mass extinction and mammals who were gaining ground on the other creatures still faced predators from the age of reptiles, namely snakes. 

Snakes have been on since the cretaceous period, starting small-sized but growing ever since to target larger vertebrates. 

We even have fossil evidence of them eating dinosaur hatchlings. Small mammals and earliest primates were on the prey list too, so snakes represent ancient and continuous threats to primates till now. 

After the extinction event, the snakes started getting venomous and henceforth the continuous threat of them to primates of that time surely has shaped us in key edge to make us better conscious towards the ancient predator. 

For example, our visual system: Primates have better eyesight than many other mammals. Hence, we rely on this sense more than our sense of smell which is generally the main one in other mammal groups. 

We have front-facing eyes which provide great depth perception and also, we have large regions of the brain to control the optical control and processing. primates like us can see the full spectrum of color which the majority cannot. 

DIFFERENCES IN THE QUALITY OF VISION FURTHER SUPPORT THE HYPOTHESIS

Primates in Madagascar or the lemurs have the worst eyesight amongst the primates. This is because they didn’t have to deal with venomous snakes throughout their evolution. 

This is because the snakes with the most venomous potent could not make it to the island of Madagascar. While on the other hand, the primates in Asia and Africa have the best vision and most accurate and advanced colour and depth perception as they had to deal with the venomous predators for a long time due to their period of evolution. 

To access how seeing snakes helped primates evolve – click here.

PART OF THE BRAIN

Along with our visual perception, researchers have suggested that the threat posed by the venomous predators has shaped a part of our brain called the Pulvinar region which processes the visual captures and it has been found that this region is comparatively larger in primates than in other mammals. 

Scientists showed photos of snakes, apes, arms, and limbs of apes to the primates and monitored the neuron activity in the pulvinar region. It was found that the activity was the highest in the case of the photo of the snakes. 

Next, it was also found that the brain acts differently while the poses of the snake change. This could show that there are certain processes of the brain deeply embedded within to detect the level of dangers the different poses represent.

So, you can even process if a snake is ready to attack or not even if you caught a glimpse of it through the corner of your eye. 

To access How to Know if a Snake Is About to Strike – click here.

THE EVOLUTIONARY CHANGES IN SNAKES DUE TO US

Now, as our ancestors started finding these creatures potent and started attacking them, these creatures evolved themselves to defend themselves from us. 

Our lineage went through evolutionary developments like bipedalism, toolmaking, and using the tool which allowed us to attack someone we considered potent from a distance.

Recently in 2021, scientists proposed that in response to the danger from us, a new defensive ability developed in the certain cobras. Now they could attack us from a distance. 

They acquired the trait to spit venom from a distance of somewhat 2.5 meters and up to a height of about the eye level of a general human. 

That was a much rarer and recent adaptation. Researchers found that this was mainly shown in the lineages consisting of cobras. The front-facing fangs shoot venom to about the eye of a general height. 

This venom causes intensive pain throughout and can cause blindness. The researchers also found that the stages of evolutionary development of these spitting cobras were during a period when hominins were introduced into their ecosystem. 

Venom spitting developed as early as 6.7 million years ago in the African cobras, soon after we separated lineage from chimps. And the same thing happened about 2.4 million years ago in Asian cobras too, about the time when Homo erectus first arrived in Asia. 

It is believed that these cobras developed this against us as primates were the only ones to have front-facing eyes which were vulnerable. These all hint at an evolutionary arms race going on between the primates and the snakes over time which can be called, THE PRIMATES VS THE SNAKES.

THE PRIMATES VS THE SNAKES

These evolutionary and counter evolutionary traits shown by the organisms are put forward by this hypothesis. In this case, none of the organisms can be called neither prey nor predator as these evolutionary traits were developed as a counter-intuitive way of the defense mechanism of the bodies.

Lastly, I’d like to say, it is interesting to find out about our lesser-known “super-power” of identifying snakes easily! Also, it was pretty surprising to find out that we also affected snake’s evolution and it wasn’t always a one-way street. 

When we think of snakes we think of danger, but it’s fascinating to see that none of us were “preys” in the traditional sense! 

Bibliography : Wikipedia, PBS.

To access Nagoya University’s research – click here.

Checkout our article about autism here!

Checkout our article about 5 of the creepiest serial killer quotes here!