It's a neat trick. Yet losing a tail, even though it will regrow, is not without cost to the lizard. It takes a lot of energy and time -- as much as a year or more -- to grow a new body part. During that time the lizard's reproductive life comes to a halt: it will not mate or bear young. If the lizard is a juvenile when it loses its tail, it simply stops growing until the new tail has grown back. And the new tail is always less impressive than the original: it's smaller and may be a different color, with differently patterned scales. Regeneration is not a perfect science, as Frankenstein taught us.
Imagine if we were capable of autotomy. In a way, we are; often in life we must leave a part of ourselves behind in order to survive. While we may someday recover what we've lost, it's a difficult and painful process, and like the lizard, we are never really the same again.
I admit I felt a terrible pang when the lizard scrambled away, leaving its precious tail behind. I had a crazy impulse to seize the tail and run after the lizard, to somehow join the two together again. But that, of course, was impossible. Once you've said goodbye to your tail, there's no going back.
[Photo by Gary Nafis]