A placard featuring an image of Russian President Vladimir Putin and reading “We are with him for the sovereignty of Russia! And you?” is seen left in front of the Russian State Duma building in central Moscow on February 24, 2022. (Photo by Kirill Kudryavtsev/AFP Photo)

Accordion player and broadcaster Gary Innes performing with dancer Rachel McLagan at The Ovo Hydro, Glasgow on Tuesday, April 5, 2022, to help launch, Hoolie in the Hydro, the World's Biggest Ceilidh, which will take place this December. (Photo by Andrew Milligan/PA Images via Getty Images)

Sweden's Fridolina Rolfo attempts to kick the ball clear of Spain's Teresa Abelleira, right, during the Women's World Cup semifinal soccer match between Sweden and Spain at Eden Park in Auckland, New Zealand, Tuesday, August 15, 2023. (Photo by Andrew Cornaga/AP Photo)

“In anatomy, heterochromia refers to a difference in coloration, usually of the iris (but also of hair or skin). Although infrequently seen in humans, complete heterochromia is more frequently observed in other species, where it almost always involves one blue eye”. – Wikipedia (Photo by StooMathiesen)

Jiff with Playboy Playmates arrives at the Playboy Super Bowl XLIX Party on Friday, January 30, 2015 in Scottsdale, Ariz. (Photo by Omar Vega/Invision/AP Photo)

Russia's figure skater Alexandra Trusova performs in a show at the CSKA arena in Moscow on February 14, 2023. (Photo by Kirill Kudryavtsev/AFP Photo)

Servicemen demonstrate their skills during a rehearsal for the Victory Day military parade which will take place at Dvortsovaya (Palace) Square on May 9 to celebrate 78 years after the victory in World War II in St. Petersburg, Russia, Thursday, May 4, 2023. (Photo by Dmitri Lovetsky/AP Photo)

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)