In this October 14, 2013 photo, ecology professor Ricardo Freitas catches a broad-snouted caiman to examine, then release back into the water channel in the affluent Recreio dos Bandeirantes suburb of Rio de Janeiro, Brazil. Caimans are like tanks, a very old species with a remarkable capacity for renovation that allows them to survive under extreme conditions where others couldn't, said Freitas, who runs the Instituto Jacare, or the Caiman Institute, which aims to protect the reptiles. (Photo by Felipe Dana/AP Photo)

During his time in Ethiopia, New York-based art director and photographer Diego Arroyo spent time with the Hamar, Mursi, Dassanech, and Arbore Tribes. They, along with several others tribes, make up the 200,000 people situated in Africa’s Great Rift Valley. The people of the Omo Valley are still primarily herders and farmers, living an isolated and simple life. While they have yet to be truly touched by globalization, they could soon disappear. Their way of life is being threatened by a massive hydroelectric dam. (Photo by Diego Arroyo)

Merit Prize Winner: “A Well Earned Rest in the Sahara”. This photo of Moussa Macher, our Tuareg guide, was taken at the summit of Tin-Merzouga, the largest dune (or erg) in the Tadrat region of the Sahara desert in southern Algeria. Moussa rested while waiting for us to finish our 45-minute struggle to the top. It only took ten minutes of rolling, running, and jumping to get back down. The Tadrat is part of the Tassili N'Ajjer National Park World Heritage area, famous for its red sand and engravings and rock paintings of cattle, elephants, giraffes, and rhinos that lived there when the climate was milder. Photo location: Summit of Tin-Merzouga, Tadrat, Tassili N'Ajjer National Park, Algeria. (Photo and caption by Evan Cole/National Geographic Photo Contest)

Tessa Evans was born without nose, a very rare facial anomaly called 'arhinia'. The little girl, who is now 18-months-old, has helped in spreading awareness about her condition across the globe.

An Afghan policeman carries a wounded man at the site of a suicide attack in Kabul March 25, 2015. Six people were killed and more than 30 injured in the suicide bombing in the Afghan capital on Wednesday that struck close to the presidential palace in the heart of the city, the Interior Ministry said. The suicide bomber had been travelling in a vehicle packed with explosives and it was not immediately clear what the target of the attack had been. (Photo by Omar Sobhani/Reuters)

A new book of photos by legendary photographer Weegee shows what industrialized, pre-gentrified New York looked like in the mid-20th century, before the city was crammed with towers and billboards. Here: this combination shows the 1945 photo “Derelict sleeping on the sidewalk outside police headquarters” by Weegee, provided by the International Center of Photography in New York, and a woman walking on the same spot on Wednesday, March 18, 2015. (Photo by AP Photo/Copyright Weegee/The International Center of Photography, Mark Lennihan)

A file photograph dated 07 January 2006 and released by Greenpeace, showing the Yushin Maru, a factory ship in a Japanese whaling fleet, injuring a whale with it's first harpoon attempt. A UN court in The Hague on 31 March 2014 halted Japan's much-criticized whaling programme, ruling that it contravenes a 1986 moratorium on whale hunting. Japan must end its 'research whaling' programme, the International Court of Justice (ICJ) said. Japan said the programme was for scientific research and permitted under international conventions. Australia had brought the case to the ICJ in 2010, charging that Japan was breaching international law by killing hundreds of whales every year for commercial purposes. Japan was “deeply disappointed” by the ruling, an unnamed government official was quoted by the Kyodo News agency as saying. But the official said Japan would stand by the ruling. (Photo by Kate Davison/EPA)

A stunt rider jumps over spectators after the final stage of the annual ABSA Cape Epic mountain bike stage race, Cape Town, South Africa, 30 March 2014. The multi day stage race is know as the “Tour de France” of mountain biking and sees 1,200 riders riding 720km in seven days. The race includes the worlds leading professional racers along with amateur cyclists. (Photo by Kim Ludbrook/EPA)