Daphne Soares, a biologist, makes an amazing discovery about alligators. The first time she got really close to an alligator (短吻鳄) was when she was helping to bold down an eight-foot American alligator. It was then that she noticed is face was covered with little black spots. This led to the discovery of the little black dots.
She started her study of the black dots. When she read the books and scientific journals, she learned that people had noticed the dots, but no one really knew what the dots were for.
To find out the secret she placed electrodes (电极) on nerves coming from some of the dots. When the nerves fired, they sent a message to the brain and created a tiny electric current. Just then she heard a small sound over a loudspeaker. She tired to see if the dots acted like eyes and temperature sensors, but nothing worked.
One day she was careless with dropping a tool into an alligator's tank. When she put her hand in the tank to get the tool out, she made small waves in the water. When they reached the alligator's face, she heard a noise over the speaker. She then realized that the dots must be sensitive to the changes in pressure when hit by waves of water.
After that, she is now studying blind cavefish. She is trying to learn whether they are blind from birth or lose their sight as they grow up. She is also doing more research on crocodilians (鳄目). She wants to find out how the genes of alligators with pressure sensors only on their faces differ from the genes of crocodilians that have pressure sensors all over their body.
