The world has been without passenger pigeons since 1914. Now, scientists want to bring them back. Geneticist Ben Novak has embarked on the project and has begun collecting passenger pigeon DNA from natural history museums. His “de-extinction” efforts are not without critics. … Novak, a researcher with the Long Now Foundation, a California think tank, wants to give the species a second chance. At the Museum of Vertebrate Zoology in Berkeley, Novak used a scalpel to slice small tissue samples from the red-painted toes of the passenger pigeons kept there. He hopes to isolate tiny bits of DNA from the...