My husband and I have been having quite the ridiculous argument for the past week. He smashed his finger and I said, “Don’t worry, it’ll grow back.”
He looked at me like I had grown two heads and lost my mind in the process. “We’re not lizards, we don’t regenerate,” he huffed as he rolled his eyes at me.
Of course we then made a bet as to who was right, the only fair way to settle things. I won.
To my husband’s credit, he didn’t know I’d just read an article about this study in Nature. Turns out occasionally kids will slice off the tops of their fingers accidentally and they will spontaneously grow back. They won’t have a fingerprint, but they will have a finger tip.
If only I’d known that back in 5th grade, when I clearly remember my friend slamming her pinkie shut in a closet door. I can still picture the little drops of blood dotting the carpet, a trail she left behind as she ran to the nurses’ office trying to save her finger.
It’s not just a weird freaky phenomenon: amputated fingers grow back. Scientists have been looking at mice to figure out how the process works. They’ve found that there are specific cells near the cuticle of your fingernail that promote growth and regrowth. These cells, known now as nail stem cells, signal nerves and bone to essentially regrow. The process is related to how your hair and fingernails continue to grow your whole life.
The regeneration process only occurs spontaneously in real life if the amputation occurs at the very tip of the finger, where the nail is located. Any lower and you’re out of luck. The potential good news is that researchers are working to figure out how these cells can be cultivated and used in other applications and amputation situations.