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All about Science - to remove misconceptions and encourage scientific temper

Communicating science to the common people

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  • Dr. Krishna Kumari Challa

    Why do we fear snakes?

    Fear of snakes is common. In most polls conducted in some parts of the world, respondents listed snakes as their top fear, outranking public speaking and heights.

    Why are so many of us afraid of snakes? And more curiously, why does our unconscious mind recognize them as a threat before our conscious mind?

    This is what the experts say:

    Our relationship with snakes is an ancient one that reaches back to the evolutionary origins of primates. Primates are really differentiated from other mammals by their heavy reliance on vision as the primary sensory modality with the environment. If you want to understand why primates evolved, you have to address why they have such good vision.

    The predator-prey relationship between snakes and primates across tens of millions of years enhanced our visual acuity. 

    Avoiding predators and getting food are the two main selective pressures operating on organisms. The idea is that the unique conditions under which primates were living, that is, being active at night like other mammals but resting during the day in trees where sunlight penetrates, instead of in caves or burrows, allowed them to expand their visual sense as a way to avoid being eaten by snakes.

    Molecular evidence bolsters the idea of ancient snake predation on primates. Researchers have found that primates in Africa and Asia, where cobras live, have evolved some immunity toward cobra venom. But primates in Madagascar and South America, where there are no cobras, have no immunity.

    Even today, there seems to be a biological tendency for primates to perceive snakes as a threat.

    If a young, naïve monkey watches a video of older monkeys reacting carefully to a snake, they will learn to do that. But if you splice in a flower where the snake was, they don't learn to react carefully toward the flower.

    Even captive-born-and-raised rhesus macaques, who likely haven't been harmed by snakes, respond with "fearful fascination" to them.

    Primate vision is highly snake-sensitive.

    This fact is beyond primatology and enhanced by the fields like neuroscience, evolutionary theory, genetics and molecular biology, to name a few.

    While constricting snakes were instrumental in the origin of primates and the initial changes in their vision, venomous snakes, appearing later, were very important in facilitating the changes in vision that led to anthropoid primates.

    Two mammalian visual systems are key to this idea: the superior colliculus-pulvinar visual system and the lateral geniculate nucleus visual system. The first system enables our unconscious detection of an object in our environment. The second, slightly slower, system allows for conscious recognition of the object and the ability to assign intent to it. Both visual systems are more developed in primates than in other mammals, and even more so in anthropoids.

    If you've ever had the experience of walking on a trail and coming across something that could be a snake, you might suddenly freeze or jump away before you actually recognize that there is a snake in front of you. The recognition taps into the conscious visual system, but the unconscious visual system gives you the ability to get out of danger more quickly.

    Evolution at its best!

    https://www.ucdavis.edu/magazine/why-do-we-fear-snakes#:~:text=Both...

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  • Dr. Krishna Kumari Challa

    Oregano oil shows promise as natural fire ant repellent
    Oregano essential oil, particularly its compound carvacrol, effectively repels invasive fire ants and disrupts their nest-building behavior. Carvacrol and related plant-derived compounds are biodegradable, less toxic to humans and beneficial insects, and may offer a sustainable alternative to synthetic pesticides for fire ant management.

    Ginson George et al, Repellent effect of oregano essential oil and carvacrol analogs against imported fire ants, Pest Management Science (2025). DOI: 10.1002/ps.70297

  • Dr. Krishna Kumari Challa

    Blink to the beat: Scientists discover that when we listen to music, we unconsciously blink our eyes
    Spontaneous eye blinks synchronize with the beat of music, reflecting involuntary auditory-motor synchronization even in non-musicians. This effect disappears when attention is diverted, indicating that focus on music is required. The findings suggest a link between auditory processing and oculomotor control, offering potential for non-invasive rhythm assessment and therapeutic applications.

    Wu Y, et al. Eye blinks synchronize with musical beats during music listening, PLOS Biology (2025). DOI: 10.1371/journal.pbio.3003456