Researchers Find Regenerated Lizard Tails Are Different From Originals

Just because a lizard can grow back its tail, doesn’t mean it will be exactly the same. A multidisciplinary team of scientists from the University of Arizona and Arizona State University examined the anatomical and microscopic make-up of regenerated lizard tails and discovered that the new tails are quite different from the original ones. The findings are published in a pair of articles featured in a special October edition of the journal, The Anatomical Record.

“The regenerated lizard tail is not perfect replica,” said Rebecca Fisher, an associate professor at the UA College of Medicine-Phoenix. “There are key anatomical differences including the presence of a cartilaginous rod and elongated muscle fibers spanning the length of the regenerated tail.”

Researchers studied the regenerated tails of the green anole lizard (Anolis carolinensis), which can lose its tail when caught by a predator and then grow it back. The new tail had a single, long tube of cartilage rather than vertebrae, as in the original. Also, long muscles span the length of the regenerated tail compared to shorter muscle fibers found in the original.

"These differences suggest that the regenerated tail is less flexible, as neither the cartilage tube nor the long muscle fibers would be capable of the fine movements of the original tail, with its interlocking vertebrae and short muscle fibers," said Fisher, who also is an associate professor in the School of Life Sciences at ASU. "The regrown tail is not simply a copy of the original, but instead is a replacement that restores some function."