Evolution: development of the elephant trunk (Introduction)

by David Turell , Tuesday, July 19, 2022, 23:26 (647 days ago) @ David Turell

Skin on top and bottom differ:

https://www.smithsonianmag.com/smart-news/skin-helps-explain-why-elephant-trunks-are-so...

"The top side of an elephant’s trunk is more pliable and can stretch 15 percent farther than the underside of the trunk, according to a new paper published Monday in Proceedings of the National Academy of Sciences.

"The findings not only contribute to the scientific understanding of trunk biomechanics, which hadn’t received much attention during the 20th century

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"But when they took a closer look, they realized elephant appendages were asymmetrical. To analyze elephant trunks, researchers challenged two African savanna elephants—one male, one female—to reach for bran cubes and apples outside of their enclosure at Zoo Atlanta.

"Researchers filmed the elephants using a high-speed camera, then analyzed the footage. When they took a closer look, they realized the top and bottom of the trunks were moving differently. At first, they thought this was an error, so they stretched out frozen skin samples from an elephant who had died at the zoo. This test confirmed that the top of the trunk was, indeed, more flexible and could stretch farther than the bottom. They also discovered that the top skin is folded, while the bottom skin is wrinkled.

"'Flexible skin folds are the elephant's innovation," David Hu, a mechanical engineer at Georgia Tech and one of the study’s authors, says in a statement. "They protect the dorsal section and make it easier for the elephant to reach downward, the most common gripping style when picking up items.'"

Comment: it is always surprising when scientists are amazed at how evolution produced perfect designs, as in the elephant trunk. Remember Velcro was first designed in nature.