Did natural selection favor darker skin tones? Professor Nina Jablonski never believed that cancer could have an effect on the evolution of skin color, and new research may prove her right.

Suzan Murray, Chief Veterinarian at the National Zoo, describes her childhood dream of becoming a veterinarian and makes a special trip to visit her favorite elephant, Shanthi.

Yearning to be among the stars led Janet Kavandi to a fulfilling career with NASA.