Synchronized swimming in dolphins occurs when one dolphin mimics the movements of another dolphin. Studies of this behavior in marine mammals have focused on dolphins in aquariums, but marine biologist Dr. Emily Carson and her team have shown that it can occur in wild dolphin populations as well. In their research, which focused on a wild population of bottlenose dolphins (Tursiops truncatus) in the Gulf of Mexico, the researchers further reported that synchronized swimming most commonly occurred in female dolphins and across different age groups instead of within a single age group. Which choice best describes the function of the first sentence in the text as a whole?