Why Do We Wrinkle When Wet?

Summary

The video explores the intriguing phenomenon of wrinkled fingers and toes after prolonged exposure to water. Initially thought to be caused by osmosis, research reveals it is actually an involuntary response from the nervous system that constricts blood vessels, leading to the wrinkling. This may have an evolutionary advantage, enhancing grip and stability in wet conditions, as evidenced by a study showing that wrinkly digits improve the ability to pick up wet objects. The video concludes by questioning why we don't always have wrinkled skin, suggesting that constant wrinkling could reduce sensitivity.

Takeaways

• 💧 Immersion in water for over 10 minutes typically causes fingers and toes to wrinkle.
• 🔬 The initial belief was that wrinkling was due to osmosis, where water enters the outer skin layer.
• 🧠 In 1935, researchers discovered that nerve damage affects the wrinkling response in fingers.
• 🔗 Wrinkled skin is an active response from the nervous system, constricting blood vessels beneath the skin.
• 🌿 Some biologists theorize that wrinkly skin might have provided evolutionary advantages in wet environments.
• ⚖️ Wrinkled skin may have improved grip for our ancestors while gathering food from wet sources.
• 🚶‍♂️ It could also enhance stability on slippery surfaces during rainy conditions.
• 📊 A 2013 study found that individuals with wrinkled fingers were 12% faster at picking up wet objects.
• 🧩 No difference was observed in picking up dry objects, indicating a specific benefit for wet handling.
• ❓ Constant wrinkling isn't beneficial since it reduces skin sensitivity, which is crucial for grip.

Q & A

What causes fingers and toes to wrinkle when immersed in water?

Fingers and toes wrinkle due to an involuntary response from the nervous system that constricts blood vessels below the skin, causing the upper layers to pucker.

What was the initial belief about the cause of wrinkled skin in water?

Initially, it was believed that wrinkled skin was a result of osmosis, where water passed into the dry outer layer of skin, expanding it without affecting the underlying tissue.

What did researchers discover in the 1935 study regarding nerve damage?

Researchers found that patients with nerve damage did not experience wrinkling in their fingers when immersed in water, indicating that the phenomenon is linked to the nervous system.

What evolutionary purpose might wrinkled skin serve?

One theory suggests that wrinkled skin may have improved grip in wet conditions, helping our ancestors gather food from streams or navigate slippery terrains.

How did the 2013 study test the grip effectiveness of wrinkly skin?

The study tested subjects with wrinkly and non-wrinkly fingers on their ability to pick up wet and dry objects, finding that those with wrinkly digits picked up wet objects 12% faster.

Why is it hypothesized that our skin isn't wrinkly all the time?

It's hypothesized that wrinkled skin may reduce sensitivity, making it less advantageous for tasks requiring fine touch, which is why it only occurs under prolonged moisture exposure.

What is the relationship between wrinkly skin and sensitivity?

Wrinkly skin may decrease sensitivity, which could be detrimental for certain tasks, indicating that the benefits of improved grip must outweigh the loss of tactile feedback.

What kind of objects were used in the study to test the effects of wrinkly skin?

The study involved various wet and dry objects, including marbles, to assess the grip performance of subjects with wrinkly versus non-wrinkly fingers.

How does the wrinkling of skin compare to car tires?

Wrinkled skin helps channel water away from the surface, similar to how the treads on car tires provide better traction on wet roads.

What call to action does the video make at the end?

The video encourages viewers to submit questions and subscribe to the SciShow channel on YouTube for more content.