Microbiologist Christina Agapakis (left) and artist Sissel Tolass show off the cheese they made with bacteria from human skin. The project was part of Agapakis' graduate thesis at Harvard Medical School. Courtesy of Grow Your Own ... Life After Nature at Science Gallery at Trinity College Dublin hide caption

itoggle caption Courtesy of Grow Your Own ... Life After Nature at Science Gallery at Trinity College Dublin

Cows graze in front of the Rosengarten mountain massif in northern Italy. Pasture grazing is practiced throughout the Alps. Matthias Schrader/Associated Press hide caption

itoggle caption Matthias Schrader/Associated Press

Archaeologists believe that ancient farmers used pots made from these pottery shards to make cheese — a less perishable, low-lactose milk product. Nature hide caption

itoggle caption Nature

Tim Opper, of Cabot Cheese, inspects equipment that separates whey protein from sugar in the company's whey processing plant. Dan Charles/NPR hide caption

itoggle caption Dan Charles/NPR