Learning from lizards

The speedy lizard was streaking across the tabletop when suddenly one foot hit a slippery spot.

The reptile skidded but never broke stride, making a split-second adjustment as it darted onward. Not that you could tell just by looking.

The true essence of the animal's grace became apparent only afterward, when its movements, recorded with Hollywood-style motion-capture technology, were played back in slow motion.

This is the lab of Tonia Hsieh, a Temple University biologist who studies life on the move.

The cockroach, scampering upside down on a ceiling. The elderly human, struggling to navigate a patch of ice. The pale-hued ghost crab, able to dance across the sand on pointy legs without sinking. Whether a creature has eight legs or zero, Hsieh wants to know how it gets around.

An assistant professor at Temple since 2010, she seems driven by the passion for knowledge for its own sake, describing quirky aspects of animal biology with such phrases as "utterly unbelievable!" or "the weirdest thing ever!"

Her work has had practical implications as well, in such diverse fields as robotics and adhesives. The latter occurred while she was just an undergraduate at the University of California, Berkeley, where Hsieh played a key role in figuring out how the gecko sticks to a wall. Those findings earned her and colleagues a paper in the prestigious journal Nature, in 2000, and now numerous efforts are under way to commercialize gecko-inspired adhesives.

At Temple, the goal of the lizard study is to use the animals as a model for humans, to figure out better ways to prevent falls among the aged.

Why lizards? That's because Hsieh and postdoctoral fellow Kyle Mara are using two species - the frilled dragon and the brown basilisk - that share an unusual characteristic with humans: the ability to run on two legs.

If the scientists can figure out how these lizards remain upright on varied terrain, they hope some of the lessons can be used to guide human therapy or treatment.

The basilisk, meanwhile, has an added ambulatory skill that is of no use to the study. But Hsieh, whose passion for crawling critters began when she was a toddler, can't resist pointing it out. The lizard is able to run on water, and thus is sometimes called the Jesus lizard.

"They're absolutely fabulous!" she said.

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