Young man making the O.K. sign. (Photo by George Marks/Retrofile/Getty Images). Circa 1950s

Kambeba Indian, Dream Braga, 18, aims his arrow in a jungle near the village Tres Unidos, Amazon state May 9, 2015. Dream Braga has been shooting fish with a bow and arrow for most of his life. In the Amazonian village where he grew up, that was what kids did for food and fun. He participated in the Indigenous Archery Project which recruits Amazon native children to compete with modern archery equipment and try for a place on the national team, with the 2016 Olympics in Rio de Janeiro as their ultimate goal. After training with Olympic coaches for three months, he has now been promoted to Brazil's national team. (Photo by Bruno Kelly/Reuters)

Sheep walk as they are herded to summer pastures in Serra da Estrela, near Seia, Portugal June 27, 2015. In late June, shepherds young and old in the Seia region of central Portugal start guiding sheep, goats and cattle to the Serra da Estrela, the country’s highest mountains, in search of better pastures. There they stay until the end of September. Modern-day shepherds may have mobile phones to keep in touch with family and friends, but their lifestyle has changed little for centuries. The sound of cowbells and the bark of longhaired mastiffs starts early in the morning as the animals – often decorated with traditional woollen balls on their horns – are herded up steep, narrow paths. (Photo by Rafael Marchante/Reuters)

Balloons are inflated at the Bristol International balloon fiesta in south west England August 6, 2015. Now in its 37th year, the Bristol International Balloon Fiesta is Europe's largest annual hot air balloon event in the city that is seen by many balloonists as the home of modern ballooning. (Photo by Toby Melville/Reuters)

Samburu tribesmen stand during the Maralal Camel Derby, Kenya, August 15, 2015. Maralal, a small, arid town about an eight-hour drive north of the Kenyan capital Nairobi, holds an annual camel festival, bringing together members of the Samburu, Turkana and Pokot semi-nomadic cattle-herding tribes. (Photo by Goran Tomasevic/Reuters)

Men carry others, so they do not soil their shoes and clothes, through a mudslide caused by Tropical Storm Erika in Carries, Haiti, August 29, 2015. Erika, a tropical storm that killed 20 people on the Caribbean island of Dominica and at least one person in Haiti, fell apart on Saturday over eastern Cuba, the U.S. National Hurricane Center said. (Photo by Andres Martinez Casares/Reuters)

A vendor drinks water as she waits for customers at a roadside flower market in Ahmedabad, India, February 8, 2017. (Photo by Amit Dave/Reuters)

A cowgirl participates in the barrel race competition at the Bill Pickett Invitational Rodeo on April 1, 2017 in Memphis, Tennessee. The Bill Pickett Rodeo is the nations only touring black rodeo competition. The rodeo celebrates western heritage and the contributions that black cowboys and cowgirls have made to the sport of rodeo. (Photo by Scott Olson/Getty Images)