Some animals may have the comprehension necessary for language. Never mind that they actually cannot talk. Scientists are encouraged by the clues; a word-learning pet dog has given. Rico, a smart border collie, with a “vocabulary” of 200 words showed exceptional ability in retrieving specific toys when asked to fetch them. Like young children, Rico was found to use a system called “fast-mapping, which is used to learn new words by matching new words to new objects.”It shows that fast-mapping is not specific to humans, that it probably has a more general purpose in figuring things out in your world,” says Julia Fischer at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany. Fischer adds the results suggest there may be reasons other than comprehension which have stopped language evolving in dogs and chimps.