The Enemy, 1944. With the outbreak of world war two, photojournalism was enlisted in defence of Mother Russia. In this photo by Anatoli Egorov, who was wounded in action, corporal Stepan Vasiljevich Ovcharenko shoots at enemy troops with a machine gun. (Photo by Anatoli Egorov/Lumiere Brothers Center for Photography)

(L-R) Recording artists Ally Brooke, Normani Hamilton, Dinah-Jane Hansen, Lauren Jauregui and Camila Cabello of Fifth Harmony attend the 2016 Billboard Music Awards at T-Mobile Arena on May 22, 2016 in Las Vegas, Nevada. (Photo by David Becker/Getty Images)

Tanzania, 1964. A touching moment between primatologist and National Geographic grantee Jane Goodall and young chimpanzee Flint at Tanzania's Gombe Stream Reserve. (Photo by Hugo van Lawick via National Geographic)

“Sniff out the Appenzell Cheese”. Alexander Hunter, 30, of Greenwich, Conn., took this photo in Appenzell, Switzerland, in September 2014. (Photo by Alexander Hunter)

The first legal wedding ceremony in history was performed in a hot tub when Leslie Davis, 23, and Richard Bustardo, 29, got married during the Backyard Living Show in Los Angeles, March 26, 1975. The ceremony was held in a five-foot hot tub, with the bride wearing a bikini and the groom attired in swimming trunks and top hat. In background is best man Arnold Holland and bridesmaid Bonnie Heckenbach, who joined the couple in the same hot tub. Officiating is Betty Jane Shaw, left. (Photo by Harold Filan/AP Photo)

A women sell food under the wing of a plane wreckage being used as housing in M'Poko Internally Displaced Persons camp in Bangui, Central African Republic on Saturday, February 13, 2016. The M'Poko IDP camp, just outside the capitol's airport, currently houses close to 20,000 people displaced due to the ongoing conflict in Central African Republic. (Photo by Jane Hahn/The Washington Post)

South American sea lion. Valencia, February 8, 2012. (Photo by Ger Art; Source: Flickr)

A hen, a dog and a rabbit playing cards, circa 1956. (Photo by Evans/Three Lions)