Gnomes are said to be underground dwellers who can move as easily through solid earth as humans move through air. Gnomes appeared in stories and legends dating back to the 1500s and were thought to be the protectors of mines and treasures. Currently, gnomes are almost synonymous with gardens but originally were portrayed as reluctant to interact with or be near humans.
Were there ever people discovered to be living underground? Throughout history many religions have believed in a subterranean realm inside the Earth. In Hinduism the idea of Patala, or that which is below the feet, is described as having many levels of life below us ruled by nagas. Recently people have been discovered living in underground dwellings for a variety of reasons. In Bucharest, Romania, there are hundreds of people living in a tunnel system due to homelessness and closed orphanages.
The writer and director of The Descent explained that the creatures, referred to as crawlers, were human. “They’ve evolved in this environment over thousands of years. They’ve adapted perfectly to thrive in the cave. They’ve lost their eyesight, they have acute hearing and smell and function perfectly in the pitch black. They’re expert climbers, so they can go up any rock face and that is their world.”1
There are over four hundred miles of caves to explore in the Mammoth Caves alone.
Aboveground, vision is useful for spotting predators, but in the dark world of caves, eyes become of little use. We talked to Bob Maki, a former biology teacher (and Kelly’s dad!) to learn more about how animals adapt to their environments deep underground.
Kelly: “These humans in The Descent evolved and adapted to their surroundings. Do you think that’s a realistic portrayal of what happens in nature?”
Bob Maki: “I think what happened was exactly right. Their skin tone was white . . .”
Meg: “And what would explain that?”
Bob Maki: “When you’re in the sun your body produces melanin to darken your skin tone to protect you from the sun’s rays.”
Kelly: “And why did their eyes look the way they did?”
Bob Maki: “Their eyes changed over time too because there was no light. They became pretty much useless because it was dark all the time.”
Kelly: “It’s like bats, right?”
Bob Maki: “Yes! They use their sense of hearing and echolocation to navigate around.”
Meg: “Did the creatures in The Descent have evolved ears?”
Bob Maki: “It appeared that their ears became larger so they could better hear things. This would be an adaptation to hear things better in the dark and their surroundings.”
Kelly: “What other adaptations did you notice?”
Bob Maki: “Their teeth appeared to evolve into more animal-like teeth like a wolf or a bear. They needed those teeth to kill and eat the kinds of animals they were surviving off of in the cave.”
Meg: “Or to eat humans!”
Bob Maki: “They also appeared to adapt to walk on all fours to make it through the low height of the caves. The way they moved made it seem like they adapted to move through the small spaces and use their limbs more like animal appendages.”
Kelly: “That definitely upped the creep factor for me.”
Meg: “You never like when things or people move in strange ways in horror movies!”
Kelly: “It’s scary!”
Bob Maki: “They also seemed to have a moist, shiny, slippery skin. I don’t know why they had it exactly but it must have helped them survive someway.”
Kelly: “What are these things technically speaking?”
Bob Maki: “Creatures that only live in caves are known as troglobites and people who live in caves are called troglodytes.”
Meg: “What are some examples of animals who live in caves without light?”
Bob Maki: “There’s an amphibian called an olm that kind of looks like a snake.”
Kelly: “I’m creeped out already!”
Bob Maki: “I was reading about it and it can survive up to ten years without eating.”
Kelly: “Do I dare ask what it eats?”
Bob Maki: “It eats bugs or whatever other small animal it finds and swallows it whole. There are a lot of different animals that only live in caves like snakes, salamanders, and some fish.”
Meg: “Have they adapted, too, to live in that environment?”
Bob Maki: “They have the adaptations I mentioned for the other creatures and they can have slower metabolisms too to conserve energy.”
Kelly: “The other term, troglodyte? That’s just used in relation to people who live in caves?”
Bob Maki: “Correct. Prehistoric ‘cave men’ are considered troglodytes and others who have lived in caves throughout history.”
Kelly: “I don’t know about you, Meg, but after seeing this movie the last thing I’m planning to do is go cave diving let alone move into one.”