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)

Guards wait for the start of former Egyptian President Hosni Mubarak's funeral at Field Marshal Mohammed Hussein Tantawi Mosque east of Cairo, Egypt on February 26, 2020. (Photo by Amr Abdallah Dalsh/Reuters)

A fruit bat eats lettuce as it hangs from a rope during a behind the scenes interactive live stream from the Oakland Zoo on April 16, 2020 in Oakland, California. Since the Oakland Zoo has been closed to the public during the shelter in place, they are offering a subscription based service that will feature five weekly behind the scenes live streamed interactive programs that will feature animal keepers and their animals. Viewers are able to interact with the keepers by submitting questions to about the animals. (Photo by Justin Sullivan/Getty Images)

An Afghan laborer works at a brick kiln, in Jalalabad, Afghanistan, 24 February 2020. Afghan President Ghani said on 21 February, said that a seven-day reduction in violence promised by the Taliban will determine the government's next steps in Afghanistan's peace process. The Taliban has announced a decrease in hostilities in an agreement with the United States as a preliminary step to signing a peace deal with Washington on 29 February. (Photo by Ghulamullah Habibi/EPA/EFE)

A model rehearses with a fabric face mask on, designed by Zhou Li for her Autumn/Winter 2020 collection show, during China Fashion Week in Beijing, following the novel coronavirus disease (COVID-19) outbreak, China on May 3, 2020. (Photo by Tingshu Wang/Reuters)

A farmer carries a bundle of wheat after harvesting it from a field in the Gharbia Governorate, as Egypt ramps up efforts to slow the spread of the coronavirus disease (COVID-19), Egypt on May 14, 2020. (Photo by Mohamed Abd El Ghany/Reuters)

Experts of the Anti-Mine Center of the Russian Defense Ministry clear mines at a motorway linking the cities of Stepanakert and Goris in Nagorno-Karabakh on November 23, 2020. (Photo by Stanislav Krasilnikov/TASS)

Young women wearing facemasks and traditional costumes of Song dynasty and Tang dynasty are seated on a bench in a park next to the East Lake in Wuhan, in China’s central Hubei province on May 17, 2020. The Guardian picture desk has chosen on December 17, 2020, the AFP photojournalist Hector Retamal as “Agency Photographer of the Year 2020” for his coverage of the novel coronavirus Covid-19 pandemic in Wuhan, China. (Photo by Hector Retamal/AFP Photo)