The tusk of a woolly mammoth that lived some 18,000 years ago, from which researchers sequenced the extinct mammal's entire genome, is seen in northeastern Siberia in this photo from 2015. (Photo by Love Dalen/Handout via Reuters)

Forrest Walker, “Police Walk”. Walker describes this shot, taken in 2015 at the last officially permitted Pride parade in Istanbul, as a tense and surreal experience. His focus is on a woman walking calmly in front of a line of riot police, her attitude part defiance and part performance. (Photo by Forrest Walker/All About Photo awards 2025 via The Guardian)

The view at night from the Shanghai Tower in Shanghai, China on August 7, 2015. The tower is technically smaller than the Burj Khalifa in Dubai but, while the observation deck of Dubai’s mega-structure is at 556m, the Shanghai Tower’s is at 561m, meaning the view is a little higher. (Photo by Paul Reiffer/REX Shutterstock)

Tajammu Al-Ezza brigade fighters react while firing a Grad shell towards forces of Syria's President Bashar Al-Assad stationed in Salhab village, Hama countryside, May 7, 2015. (Photo by Mohamad Bayoush/Reuters)

A Colombian Nukak Maku Indian boy gestures in a refugee camp at Agua Bonita near San Jose del Guaviare of Guaviare province September 3, 2015. Since emerging from the jungle in 2005, half naked and carrying blowpipes, the Nukak have lived in settlements near the frontier town of San Jose del Guaviare, a humid outpost in the Amazon 400 km (250 miles) southeast of the capital Bogota. (Photo by John Vizcaino/Reuters)

Shepherd Ben Blackmore stands with his flock of Exmoor Horn sheep in Savile Row, London, Britain October 5, 2015. The Campaign for Wool marked the beginning of Britain's national Wool Week on Monday, on one of London's most renowned streets. (Photo by Peter Nicholls/Reuters)

A model wears a creation by Taiwanese fashion house Shiatzy Chen as part of its Spring-Summer 2016 ready-to-wear fashion collection, presented during the Paris Fashion Week in Paris, France, Tuesday, October 6, 2015. (Photo by Jerome Delay/AP Photo)

A model on a wheelchair presents creations by designer Takafumi Tsuruta from his Spring/Summer 2016 collection for his brand Tenbo, during Tokyo Fashion Week in Tokyo, Japan, October 13, 2015. (Photo by Yuya Shino/Reuters)