CAMBRIDGE, UK – A new study published Monday in the journal Proceedings of the National Academy of Sciences reveals the reasons why humans don’t have the ability to climb up walls.
Scientists at the University of Cambridge’s Department of Zoology studied 225 species of climbing animals and found that geckos were the biggest animals capable of resembling Spiderman’s moves.
Climbing animals like mites and geckos can scale a vertical wall or other tricky surface thanks to adhesive footpads. The study findings suggest that the heavier or bigger the animal, the larger their sticky footpads must be. For instance, just 0.02 per cent of a mite’s body is adhesive pads and spiders need around 0.92 per cent coverage to stick to any surface, whereas 4.3 per cent of a gecko’s body surface is adhesive footpads.
“This poses a problem for larger climbing animals because, when they are bigger and heavier, they need more sticking power, but they have comparatively less body surface available for sticky footpads. This implies that there is a maximum size for animals climbing with sticky footpads – and that turns out to be about the size of a gecko”, lead author David Labonte explained.
And a human is so large and heavy that it would require adhesive pads on 40 percent of their body to be able to climb up a wall with the same ease as geckos. This means that, in your front, you’d have to be sticky pad from your toes to the top of your chest. Scientists joked around by mentioning the mess this would cause when trying to hug someone.
Besides, a human would need to have one-meter-long and 40-centimeters-wide feet to scale a wall, which wouldn’t be practical if one wants to run after their enemies. Study author Walter Federle said in a news release that a human would need shoes in European size 145 or US size 114 to climb up a wall the way a gecko does.
But scientists did find exceptions in certain animals whose sticky footpads did not increase as fast as they should, compared to other species. The pads actually got stickier. For instance, researchers found that tree frogs had stickier rather than bigger pads, according to study co-author Christofer Clemente. He pointed out how impressive it was the fact that there are two different evolutionary solutions to the same issue of getting big and sticking to walls.
Source: Discovery News