Description: [caption id="" align="aligncenter" width="419" caption="An exhibit of rocks and minerals in the United States National Museum, now the Arts and Industries Building, The exhibit includes Balls of Brecciated Marble from Japan in the middle case and other samples of rocks and minerals in the other cases next to it, 1900s, by Unknown photographer, Photographic print, Smithsonian
Description: [caption id="" align="aligncenter" width="301" caption="Photograph of the "Dynamics of Evolution," a major exhibit at the National Museum of Natural History. The "People Tower" in the foreground is covered with more than 100 larger-than-life sized photos of faces that show genetic traits, such as blue or brown eyes, or black or blonde hair, May 1979, by Unidentified