Recent research by marine biologists suggests that bottlenose dolphins have names for themselves. Scientists played sounds that they had identified as the names of particular dolphins through a synthesizer (so they did not sound like the voices of particular dolphins) and found that dolphins would respond to the names of other dolphins they were related to or associated with, but ignored the names of strangers. This discovery suggests a much greater degree of self-awareness in aquatic mammals than was previously suspected. If this research holds up, what does it suggest about dolphins