This piece on bringing the Aurochs back from extinction was just published by Time.
The only place to see an aurochs in nature these days? A cave painting. The enormous wild cattle that once roamed the European plains have been extinct since 1627, when the last survivor died in a Polish nature reserve. But this could soon change thanks to the work of European preservationists who are hoping they can make the great beast walk again. If they succeed — through a combination of modern genetic expertise and old-fashioned breeding — it would be the first time an animal has been brought back from extinction and released into the wild.