HUMAN nails are as strong as a horse’s hoof. And it is this structural strength that allows us to grip, scratch and even make those horrible nail-on-a-chalkboard screeches, without damaging our nails.
Only primates evolved finger and toenails, probably to provide better grip on tree trunks and branches.
Roland Ennos and his team at the University of Manchester, UK, wondered what gave the nail its structural properties. He says, “I have always been a bit of a nail-biter, and I noticed that whenever you bite your nails, they never break into the quick of your skin. And for a material,…
