The Trouble With Never Growing Old...

...Is never growing up.

Girl who never ages could hold key to 'biological immortality,'

Eight-year-old Gabby Williams weighs only 11 pounds. The tiny girl from Billings, Mont., still looks like an infant and needs to be cared for as if she is a newborn, with her mother and father changing her diapers and feeding her multiple times a day.

Her mother, Mary Margret Williams, told ABCNews.com that Gabby hasn't changed much over the years. In fact, her skin still feels like a baby's and her hair is still fine-textured. "She has gotten a little longer and we have jumped into putting her in size 3-6 month clothes instead of 0-3 months for the footies," she said.

"If we could identify the gene and then at young adulthood we could silence the expression of developmental inertia, find an off-switch, when you do that, there is perfect homeostasis and you are biologically immortal," Walker said.

By "biologically immortal" he means people would still die from disease and in accidents, but they wouldn't experience the normal effects of aging.

"You wouldn't have the later years," Walker said, "you'd remain physically and functionally able."

At this point, I think I'd want them to be able to rewind a few years, too.