In their study, "Context-dependent changes in motor control and kinematics during locomotion: modulation and decoupling," Foster surgically inserted electrodes into the forelimbs and hind limbs of seven male green anole lizards. She then tracked the lizard movements on a flat and 90-degree incline and a broad and narrow perch, using high-speed video to record movements and electromyography to monitor electrical activity in the muscles.
"We expected to see a one-to-one correlation between the muscle activity and movements because motion is generally driven by muscles," Higham said, "but as we changed the structure of their habitat and they changed their motions, we were surprised to find very few accompanying changes in muscle activity."
For instance, the researchers found that while the lizard movements changed considerably when they were running along narrow perches (compared to broad perches), there were few significant changes in muscle activity. And when the lizards were running up an incline, they noted more changes in muscle activity than movement.
"This generally means we can't understand what the muscles are doing just by what we see," Higham said. "We also found that variability in muscle activity differed between the treatments, raising another question: Does variability in muscle activity reflect a preferred way of moving or just reflect what they've always done? This has unearthed a lot of questions about ecology, evolution, how parts of animals evolve and how they respond to their environment."
Though these 2-inch-long green anoles weigh just 5 grams about the same as a U.S. nickel their muscles work the same way as every other vertebrate.
"This means what we learn from studying their
|Contact: Iqbal Pittalwala|
University of California - Riverside