The broad field of animal communication encompasses most of the issues in ethology. Animal communication can be defined as any behavior of one animal that affects the current or future behavior of another animal. The study of animal communication, called zoo semiotics (distinguishable from anthroposemiotics, the study of human communication) has played an important part in the development of ethology, sociobiology, and the study of animal cognition. Animal communication, and indeed the understanding of the animal world in general, is a rapidly growing field, and even in the 21st century so far, a great share of prior understanding related to diverse fields such as personal symbolic name use, animal emotions, animal culture and learning, and even sexual conduct, long thought to be well understood, has been revolutionized. A special field of animal communication has been investigated in more detail such as vibrational communication.
What are some fields of knowledge concerning the animal world that have been revolutionizes in the 21st century?
animal emotions, animal culture and learning

Beyonce's work has influenced numerous artists including Adele, Ariana Grande, Lady Gaga, Bridgit Mendler, Rihanna, Kelly Rowland, Sam Smith, Meghan Trainor, Nicole Scherzinger, Rita Ora, Zendaya, Cheryl Cole, JoJo, Alexis Jordan, Jessica Sanchez, and Azealia Banks. American indie rock band White Rabbits also cited her an inspiration for their third album Milk Famous (2012), friend Gwyneth Paltrow studied Beyonce at her live concerts while learning to become a musical performer for the 2010 film Country Strong. Nicki Minaj has stated that seeing Beyonce's Pepsi commercial influenced her decision to appear in the company's 2012 global campaign.
Which friend learned from Beyonce while preparing for the film, "Country Strong?"
Gwyneth Paltrow

Philadelphia is home to many national historical sites that relate to the founding of the United States. Independence National Historical Park is the center of these historical landmarks being one of the country's 22 UNESCO World Heritage Sites. Independence Hall, where the Declaration of Independence was signed, and the Liberty Bell are the city's most famous attractions. Other historic sites include homes for Edgar Allan Poe, Betsy Ross, and Thaddeus Kosciuszko, early government buildings like the First and Second Banks of the United States, Fort Mifflin, and the Gloria Dei (Old Swedes') Church. Philadelphia alone has 67 National Historic Landmarks, the third most of any city in the country.
Which is the biggest historical sites?
Independence National Historical Park