U.S. Army soldiers with the 1st Battalion, 501st Infantry Regiment deployed to Combat Outpost Sabari, Afghanistan scan their area as they begin a multi-day air assault mission near the Pakistani border of eastern Afghanistan's Khost province May 2, 2012. (Photo by Staff Sgt. Joshua L. DeMotts/U.S. Air Force)

A female Marine prepares to throw a practice grenade during Marine Combat Training (MCT) on February 21, 2013 at Camp Lejeune, North Carolina. Since 1988 all non-infantry enlisted male Marines have been required to complete 29 days of basic combat skills training at MCT after graduating from boot camp. MCT has been required for all enlisted female Marines since 1997. About six percent of enlisted Marines are female. (Photo by Scott Olson)

Every man looks better with a beard. Here's proof.

Deal or New Deal, Season 2. Pictured: Meghan Markle, 2006. (Photo by Paul Drinkwater/NBC/NBCU Photo Bank via Getty Images)

Emily Ratajkowski filming DKNY commercial on January 20, 2017 in New York City, USA. The 25-year-old model braved the freezing New York temperatures as she wore just a black lace bra and matching French knickers, with a pair of clumpy biker boots. (Photo by Startraks Photo/Rex Features/Shutterstock)

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)

Esau the ape at the piano. (Photo by Reinhold Thiele/Topical Press Agency/Getty Images). Circa 1900

Model Bar Refaeli arrives at amfAR's Cinema Against AIDS 2007 at Le Moulin de Mougins on May 23, 2007 in Mougins, France. The amfAR Foundation raises funds for research, education and treatment of AIDS/HIV worldwide.