The secretive indri (Indri indri) of Madagascar, the largest living lemur. It is also critically endangered and highly evolutionarily distinct with no close relatives, which makes its branch one of most precarious on the mammal evolutionary tree. In the likely event that the indri goes extinct, we will lose 19m years of unique evolutionary history from the mammal tree of life. (Photo by Pierre-Yves Babelon/Aarhus University)

Enthusiast Desirae Hepp, dressed as "Immortan Joe," poses for a portrait during Wasteland Weekend event in California City, California September 26, 2015. The four-day event has a post-apocalyptic theme and is inspired by the Mad Max movie franchise. (Photo by Mario Anzuoni/Reuters)

This family of warthogs regularly visited our campsite in the Ethiopian highlands so I set up a remote camera with a wide-angle lens to photograph them as they rummaged around for food. They just had a mud bath. (Photo by Will Burrard-Lucas/Caters News Agency)

In this April 28, 2014 file photo, a woman throws a rock and a bag at police blocking her from getting home in the Huepetuhe district of the Madre de Dios region of Peru. Security forces began destroying illegal gold mining machinery in Peru's southeastern jungle region of Madre de Dios, as authorities began enforcing a ban on illegal mining. (Photo by Rodrigo Abd/AP Photo)

A family tries to cross a flooded road amid gushing water in Kolkata, India on August 17, 2019. Heavy rain continues for a second day in Kolkata, which contuinued to flood many streets all around the city. Authorities are working overtime to clear the roads. (Photo by Debarchan Chatterjee/Zuma Wire/Rex Features/Shutterstock)

Miss Georgia USA Emanii Davis, Miss Kentucky USA Kyle Hornback and Miss North Carolina USA Devin Gant competes in the swimsuit competition during the 2016 Miss USA pageant preliminary competition at T-Mobile Arena on June 1, 2016 in Las Vegas, Nevada. The 2016 Miss USA will be crowned on June 5 in Las Vegas. (Photo by Ethan Miller/Getty Images)

People are caught in a dust storm in New Delhi, India May 23, 2016. (Photo by Anindito Mukherjee/Reuters)

In this Thursday, December 1, 2016 photo, Cat Bigney, part of the Oglala Native American tribe, waits on the shore of the Cannonball river for travelers to arrive by canoe at the Oceti Sakowin camp where people have gathered to protest the Dakota Access oil pipeline in Cannon Ball, N.D. So far, those at the camp have shrugged off the heavy snow, icy winds and frigid temperatures. But if they defy next week's government deadline to abandon the camp, demonstrators know the real deep freeze lies ahead. Life-threatening wind chills and towering snow drifts could mean the greatest challenge is simple survival. (Photo by David Goldman/AP Photo)