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)

Kumari Samita Bajracharya sits in front of devotees offers during a special puja at Kumari Ghar in Patan, Nepal, 09 April 2011. It is believed that worshipping Kumari and receiving tika from her reduces illness and avoid problems. Kumari, or Kumari Devi, is a “living goddess”. The word literally means virgin in Nepali. The Living Goddesses are young pre-pubescent girls that are considered to be incarnations of the Hindu Goddess of Power, Kali. The Kumari retires when she reaches puberty. (Photo by Narendra Shrestha/EPA)

A barn painted with the U.S. flag is seen in the snow covered field in Kanawha, Iowa, United States, January 16, 2016. Iowa will be the first state to hold its primary, with both Democratic and Republican events being held February 1, 2016. (Photo by Jim Young/Reuters)

In this September 16, 2017 photo, a music fan poses for the photo against an angel wings' mural at the Rock in Rio music festival in Rio de Janeiro, Brazil. (Photo by Leo Correa/AP Photo)

Alison Brie and Betty Gilpin host in the Netflix comedy-drama“Glow” Season 1 TV Series, 2017. (Photo by Erica Parise/Netflix/Kobal/Rex Features/Shutterstock)

Two young boys kneel on stools on either side of a round table as one uses a match to this the other's cigarette, November 12, 1928. (Photo by FPG/Getty Images)

Jenifer Lopez, 12, watches television at her home in Havana January 9, 2015. (Photo by Alexandre Meneghini/Reuters)

A Flemish demonstrator, one of thousands who gathered for a march through Brussels to protest against what the Flemings call their subjucation by the French-speaking Walloons, draws back as he is jeered by a crowd of Walloons on the pavement in a Brussels Street, on October 14, 1962. The Flemish demonstrators clashed with Walloon counter demonstrators as riot police sought to maintain order. The Flemings claim that although they form 60% of the population in Belgium, they are inadequately represented in the government, and they say, the Walloons get most of the top jobs in the armed forces and the diplomatic service. (Photo by AP Photo)