Passenger pigeons are now extinct, but the species could be brought back to life, per scientists. The species vanished from the Earth 100 years ago, but passenger pigeons were once common throughout the United States. Using DNA, researchers may now be able to revive species that have not been seen on Earth for decades…The body is being taken out of storage and displayed as part of an exhibit, reminding people of the possible effects of humans on wildlife. The display opens June 24, but not without controversy. Critics of de-extinction claim the ability to revive vanished species will discourage conservation efforts. “It’s very negative, very expensive and not going to achieve any conservation goal as far as I can see,” David Ehrenfeld, Rutgers University biologist, told the press.