Runners warm up during the Team Pants And Bra photcall at City Hall on January 26, 2012 in London, England. Team Pants and Bra sprinted through central London this morning, encouraging fellow runners to join TeamPB and proudly wear pants and bras for the Virgin London Marathon in April, representing The Prostate Cancer Charity and Breast Cancer Care. (Photo by Ian Gavan/Getty Images for Prostate Cancer)

Masked penitents holds their crosses during spring “Romeria Cruceros de Arce”, in Roncesvalles, northern Spain, Sunday, May 10, 2015. Every year on the second Sunday in spring, people with crosses march from their small Pyrenees towns to Roncesvalles Church in tribute of the Virgin. (Photo by Alvaro Barrientos/AP Photo)

A donkey is seen before the start of the procession of the “Virgem da Atalaia” during Holy Week at Alcochete, near Lisbon April 5, 2015. Women ride donkeys during the “Virgem da Atalaia” procession, that has been held annually for about 400 years. In the past, only single women rode the donkeys to ask for help from the Virgin to find a husband. (Photo by Rafael Marchante/Reuters)

A reveller holds her dog dressed in costume, during the Rio Dog Carnival, known as the Blocao – with “bloco” meaning street party and “cao” dog, during pre- carnival celebrations at Copacabana beach in Rio de Janeiro, Brazil, on February 19, 2017. (Photo by Yasuyoshi Chiba/AFP Photo)

Take me away, deer, Russia. The Nenet people of Arctic Russia use reindeer and sledges as a prime mode of transport. The animals’ navigational ability means that in severe conditions they are sometimes the only hope of survival. (Photo by Kamil Nureev/Smithsonian Photo Contest)

Drastic inequality is by no means new in New York. Jacob A. Riis was called a muckraker after he chose to spotlight the city’s poverty at the turn of the 20th century by photographing it. Here: Sweatshop in Hester Street, 1889-1890. (Photo by Jacob A. Riis/Museum of the City of New York, Gift of Roger William Riis)

Buns are stamped the Chinese characters “Ping An”, meaning peaceful and safe, inside a bakery, at Hong Kong's Cheung Chau island, China May 17, 2015, ahead of the upcoming Bun Festival on May 25. The festival celebrates the islanders' deliverance from famine many centuries ago and is meant to placate ghosts and restless spirits. (Photo by Tyrone Siu/Reuters)

A female hippopotamus named “Mali”, which means Jasmine, eats fruits arranged to look like a cake during her 50th birthday celebration at Dusit Zoo in Bangkok, Thailand September 23, 2016. (Photo by Chaiwat Subprasom/Reuters)