In this photo taken Thursday January 17, 2013, sled dogs Poncho, left, and his blind brother Gonzo are hooked up for a run at the Muddy Paw Sled Dog Kennel, in Jefferson, N.H. Poncho has taken to helping his blind brother on regular runs. (Photo by Jim Cole/AP Photo)
The photographs feature fish that have been specially treated to make the stained skeletal tissues visible through the skin and flesh. The technique, developed by Dr. Adam Summers, uses dyes, hydrogen peroxide, a digestive enzyme and glycerin to make the flesh seem to disappear. Photo: This image of the butterfly ray (Gymnura crebripunctata) helped scientists study the joints in its wings. (Photo by Adam Summers)
Singer Rihanna performs onstage during the 2011 Billboard Music Awards at the MGM Grand Garden Arena May 22, 2011 in Las Vegas, Nevada. (Photo by Ethan Miller/Getty Images for ABC)
A citizen rides in smog on December 20, 2016 in Jinan, Shandong Province of China. Air quality index (AQI) readings exceeded 400 and some schools have suspended classes in Jinan. (Photo by VCG/VCG via Getty Images)
A woman views the Mummy of Meresamun in the Ashmolean Museum's new exhibition of artifacts from ancient Egypt and Nubia on November 23, 2011 in Oxford, England. The new gallery is displaying for the first time in decades some of the finest Egyptian and Nubian artifacts in the UK. The Egyptian collection opens to the public from November 26, 2011. (Photo by Oli Scarff/Getty Images)
UFC women's bantamweight champion Holly Holm and Miesha Tate face off during the UFC 196 weigh ins at the MGM Grand Garden Arena in Las Vegas on Friday, March 4, 2016. (Photo by L.E. Baskow/Las Vegas Sun via AP Photo)