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)

People perform Chinese Lion dance in Chinatown during the Chinese Lunar New Year in Lima, Peru on February 5, 2019. (Photo by Guadalupe Pardo/Reuters)

People take part in a gay pride parade in Warsaw, Poland, on Saturday, June 8, 2019. The Equality Parade is the largest gay pride parade in central and Eastern Europe. It brought thousands of people to the streets of Warsaw at a time when the LGBT rights movement in Poland is targeted by hate speeches and a government campaign depicting it as a threat to families and society. (Photo by Czarek Sokolowski/AP Photo)

Leonhard Nienbling is shown with his 6-month old pet baboon Jackl, who holds a 6-month old kitten, its playmate, June 29, 1952. Niebling has quite an animal collection at his home in Zirndorf, Germany. (Photo by Heinrich Sanden/AP Photo)

Cave Diver, Anhumas Abyss, Bonito, Brazil: The Anhumas Abyss is an underground cavern with a crystal-clear lake below, more than 260 feet (79 m) deep. A visitor must enter through a narrow opening at the top of the chamber and rappel into the cave. Snorkeling and scuba diving in the lake reveal amazing scenery. Distinctive, conical limestone stalagmites and stalactites occupy the lake and the surrounding area, some reaching 65 feet (20 m) high. (Photo by Marcio Cabral/Nature’s Best Photography Awards 2017)

Yuri Gagarin does not always show up in full-scale astronautics. In this picture he smiles during his summer vacation in Sochi, Russia in 1961 with sunglasses and sunhat in the camera. (Photo by Imago/Eastnews)

Starlings are seen at their nesting box in a private garden in the town of Bobruisk, Belarus, April 8, 2018. (Photo by Vasily Fedosenko/Reuters)

Children in a Hong Kong refugee resettlement area watch as former Vice President Richard Nixon shows them his badminton service. Nixon visited Hong Kong, April 4, 1964, during his tour of countries in the Far East. (Photo by AP Photo)