A walker has left a handprint on a snow- covered tree trunk on Grosser Feldberg mountain in the Taunus mountain range, Germany, 16 January 2017. (Photo by Frank Rumpenhorst/DPA)

View of an American marine as he lies in a foxhole and whistles at a husky, one of the scouting dogs used during the landing on Guam, August 1944. (Photo by W. Eugene Smith/Time & Life Pictures/Getty Images)

With its huge eyes, comical name and diminutive size, Mark R. Smith’s image of a baby Hawaiian bobtail squid can’t help but raise a smile. A curiously endearing creature, the cephalopod is just 1.5cm across, its mantle cavity bearing more than a passing resemblance to a rather natty shower cap. But it is also a beautiful example of symbiosis – nature’s version of “I’ll scratch your back if you scratch mine” – for on the underside of the squid is a light organ which houses bioluminescent bacteria. The squid offers the bacteria protection and food, while the bacteria emit a glow – a handy trait that the squid uses to offset its silhouette, helping it to evade predators in the depths below. Mark R. Smith’s entry combines several images of a Hawaiian bobtail squid with different focus lengths to create a final picture with greater depth of field than normal. (Photo by Mark R. Smith/Wellcome Images/Macroscopic Solutions)

JAPAN: A businessman stands at a pond in the Kyu-Shiba-rikyu Garden on a warm and sunny day in Tokyo, Japan, March 18, 2016. (Photo by Thomas Peter/Reuters)

Demonstrators protest against police shootings and racial injustice in New York City, U.S., April 16, 2021. (Photo by David “Dee” Delgado/Reuters)

A Capetonian watches the sun rise from the top of Signal Hill as smoke engulfs the city of Cape Town, South Africa, Tuesday April 20, 2021. A massive fire spreading on the slopes of the city's famed Table Mountain, at right, is kept under control as firemen and helicopters take advantage of the low winds to contain the blaze. (Photo by Jerome Delay/AP Photo)

A man does physical exercise during sunset over the Finnish Gulf coast in St. Petersburg, Russia, Wednesday, April 14, 2021. (Photo by Dmitri Lovetsky/AP Photo)

A person gestures during the “NYC Dyke March” have a moment of silence for the LGBT community in Manhattan in New York City, New York, U.S., June 26, 2021. (Photo by David Dee Delgado/Reuters)