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)

In this Wednesday, April 3, 2019, photo, children play in the water on a beach as a mosque collapsed during the Sept. 28, 2018, earthquake is seen in the background in Palu, Central Sulawesi, Indonesia. The earthquake spawned a large localized tsunami that wiped out coastal areas, while liquefaction caused by the shaking turned entire neighborhoods into rivers of sludge. The disaster killed thousands of people, making it the world’s deadliest seismic event in 2018. (Photo by Tatan Syuflana/AP Photo)

Performers on boats take part in the Qintong Boat Festival at Qin Lake National Wetland Park on April 6, 2019 in Taizhou, Jiangsu Province of China. The boat festival is held around the Qingming Festival every year, and up to 10,000 participants from nearby villages and towns, with more than 500 boats, took part in the event this year. (Photo by Tang Dehong/VCG via Getty Images)

A swimmer competes in Le Defi Monte-Cristo (Monte Cristo Challenge) swimming event at the Chateau d'If, off the coast of Marseille, southern France, on June 21, 2019. Created in 1999 and inspired by Alexandre Dumas' character of Edmond Dantes, the Monte Cristo Challenge will take place from June 21 to 23, 2019. (Photo by Boris Horvat/AFP Photo)

Extras in the arena of the “Fete des Vignerons” (winegrowers' festival in French), during the last rehearsal in Vevey, Switzerland, 17 July 2019. Organized by the brotherhood of winegrowers, the event will celebrate winemaking from 18 July to 11 August. The arena has a capacity of 20,000 spectators and hosts a giant central LED floor of approximately 800 square meters. (Photo by Laurent Gilliéron/EPA/EFE)

Traffic lights feature illustrations of a homosexual couple in downtown Frankfurt Main, Germany, 18 July 2019. An annual gay pride parade will take place on 20 July 2019 in Frankfurt to commemorate Christopher Street Day (CSD). The event commemorates the riots that erupted following a police raid in 1969 at a gay bar on Christopher Street in Greenwich Village, New York City. (Photo by Armando Babani/EPA/EFE)

Boozed up revellers dressed up in fluorescent colours during the opening day of the 2019 Notting Hill Carnival on August 25, 2019 in London, England. Up to a million people are expected to pack the streets of Notting Hill and surrounding areas over the course of the two day event. The annual celebration of Afro-Caribbean culture takes place each August bank holiday weekend. (Photo by London News Pictures)

Participants of an unauthorized opposition rally gather in Tverskaya street in central Moscow on June 12, 2017. Authorities detained Russian opposition politician Alexei Navalny and hundreds of his supporters on Monday, as they mounted demonstrations across the nation against government corruption. Over 200 were detained in Moscow and Saint Petersburg an hour into the protest, according to an NGO that tracks arrests, with Navalny himself picked up by police in his building as he was headed to the event. (Photo by Vasily Maximov/AFP Photo)