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)

A female member of the Ahbab Al-Mustafa Battalion holds a gun as she undergoes military training in Aleppo's Salaheddine district, June 24, 2013. (Photo by Muzaffar Salman/Reuters)

People move through a waterlogged street in Gauhati, India, Tuesday, July 16, 2013. Heavy showers flooded some areas in the city on Tuesday. (Photo by Anupam Nath/AP Photo)

Women walk next to soldiers in Surcubamba, Peru, Thursday, May 21, 2015. The Joint Command of the Peruvian Armed Forces organized a humanitarian mission to Surcubamba, where health care was provided to families from nearby villages in this region called VRAEM, the acronym for Valley of the Apurimac, Ene and Mantaro rivers, where sixty percent of Peru's cocaine originates. (Photo by Rodrigo Abd/AP Photo)

A dog with a cherry blossom-shaped pin, is seen in the cherry blossom festival in Seoul, South Korea, Sunday, April 9, 2017. (Photo by Lee Jin-man/AP Photo)

A Philippine boy collects used plastic bottles to be sold at a junk shop at Divisoria market in Manila on November 29, 2017. (Photo by Noel Celis/AFP Photo)

A young festivalgoer jumps to burst a bubble at Latitude Festival at Henham Park, Britain, July 22, 2021. (Photo by Peter Cziborra/Reuters)

Bao Bao, the Giant Panda cub is seen by the media for the first time January 6, 2014 inside his glass enclosure at the Smithsonian's National Zoo in Washington, DC, a few days before going on display to the general public. Bao Bao was born at the Smithsonian's National Zoo August 2, 2013. (Photo by Paul J. Richards/AFP Photo)