Bonobo apes, primates unique to Congo and humankind's closest relative, groom one another at a sanctuary just outside the capital Kinshasa, Congo on October 31, 2006. (Photo by Finbarr O'Reilly/Reuters)

In this Sunday, March 5, 2017, photo, hospitality staff take souvenir photos in front of the Great Hall of the People where the National People's Congress is held in Beijing. (Photo by Andy Wong/AP Photo)

Brain-on-a-chip. Dazzling in green and magenta this image shows the nerve fibres (in green) produced by neural stem cells (in magenta) as they grow on a synthetic gel. Captured by a technique known as confocal microscopy, the image is part of research shedding light on how tinkering with the environment can affect the way in which nerve fibres grow. (Photo by Collin Edington and Iris Lee/Massachusetts Institute of Technology/Wellcome Images)

In this April 20, 2017 photo, a woman is aided by fellow demonstrators after falling, overcome by tear gas, during anti-government protests in Caracas, Venezuela. Tens of thousands of protesters asking for the resignation of President Nicolas Maduro flooded the streets again, one day after three people were killed and hundreds arrested in the biggest anti-government demonstrations in years. (Photo by Ariana Cubillos/AP Photo)

Gigi Hadid attends “Rei Kawakubo/Comme des Garcons: Art Of The In-Between” Costume Institute Gala – Arrivals at Metropolitan Museum of Art on May 1, 2017 in New York City. (Photo by Carlo Allegri/Reuters)

Filipino beauty candidates hide from the sun before a group photo during the media presentation of the Miss Philippines Earth 2017 held at a hotel in Manila, Philippines, 05 July 2017. A total of 40 environmentally aware and concerned Filipino young ladies will compete to represent the Philippines at the Miss Earth beauty pageant. Miss Earth is a pioneering beauty pageant that serves as a vehicle for environmental advocacy. (Photo by Mark R. Cristino/EPA)

Auditioning performers follow resident choreographer Erik Sorensen, center back, at the Sydney Dance Company in a routine during castings in Moulin Rouge's current show “Féerie”, in Sydney, Australia, Thursday, July 28, 2016. The show's artistic team is in Australia to choose new talent to perform with one of the most famous cabarets that has been illuminating Paris since 1889. (Photo by Rob Griffith/AP Photo)

Seen in a long exposure nighttime photograph, a burned van rests in a lot while a wildfire glows on the horizon in Phelan, Calif., early Thursday, August 18, 2016 2016. (Photo by Noah Berger/AP Photo)