Genetically Engineering the Natural World, it Turns Out, Could Be a Disaster

For the native species of New Zealand, European settlement was particularly cruel. The country has no endemic land predators, so many of its birds evolved without the typical avian aptitude for flight. Then came Western settlers, and along with them rats, mice, opossums, stoats, cats, and the occasional misbehaving dog. For these invaders, New Zealand’s flightless birds were a veritable feast. Numbers dwindled. Despite conservation efforts, the country still loses about 20 of its namesake kiwi birds every week.