Cattle are the most important way of livelihood for the Karamojong: they provide milk, meat, blood and money when sold, Karamoja, Uganda, February 2017. (Photo by Sumy Sadurni/Barcroft Images)

Dani tribeswoman smokes a cigarette and shows her amputated fingers in, Western New Guinea, Indonesia, August 2016. Deep in the highlands of Western New Guinea, Indonesia, lives one of the world’s most isolated tribes. Known as the Dani people, the tribe was unwittingly discovered by American philanthropist, Richard Archbold, after an expedition in 1938. (Photo by Teh Han Lin/Barcroft Images)

A Syria Democratic Forces (SDF) fighter comforts a civilian who was evacuated with others by the SDF from an Islamic State-controlled neighbourhood of Manbij, in Aleppo Governorate, Syria, August 12, 2016. The SDF has said Islamic State was using civilians as human shields. (Photo by Rodi Said/Reuters)

Tube passengers take a selfie next to a London underground roundel designed for the launching of the Night Tubes on display at Oxford Circus underground station in London, Britain, 19 August 2016. The long delayed Night Tubes service launched on 19 August. The 24-hour service will operate on Fridays and Saturdays. (Photo by Hannah Mckay/EPA)

Cairo-based artist Chanel Arif's paints for her art project called After Dinner that uses humans and their surroundings as her canvas, in her gallery in the capital of Cairo, Egypt March 2, 2017. (Photo by Sherif Fahmy/Reuters)

Turkana tribesmen walk with guns in order to protect their cattle from rival Pokot and Sambur tribesmen near Baragoy, Kenya February 14, 2017. Cattle rustling and competition for grazing have long troubled northern Kenya, but severe drought and political rivalries ahead of the elections have exacerbated the situation between ethnic tribes. (Photo by Goran Tomasevic/Reuters)

Evel Knievel is shown in his rocket before his failed attempt at a highly promoted 3/4-mile leap across Snake River Canyon in Twin Falls, Idaho, on September 8, 1974. The jump failed when the parachute on his rocket malfunctioned, opening prematurely. Knievel was uninjured. (Photo by AP Photo)

South Korean Lee Jung-sook (L), 68, wipes the tears from her North Korean father Lee Heung-jong, 88, as they bid each other a sad farewell at a resort on Mount Kumgang, North Korea, 22 October 2015. About 390 South Koreans arrived at the resort two days ago for the first face-to-face reunion of families separated by the 1950-53 Korean War in nearly 20 months. A second group of some 260 South Koreans will do the same for three days starting on 24 October. (Photo by Yonhap/EPA)