Movies like Jurassic Park have shown the wonders and dangers of bringing back extinct species. It’s not really science fiction anymore.

While we’re probably not going to be bringing back dinosaurs anytime soon – the DNA is just too damaged over that time – there is the potential for bringing back prehistoric mammals, and even animals that we’re losing in the current extinction event.

Some think that bringing back mammoths – or something like them – could help climate change by feeding on the bushes that absorb heat and thaw the permafrost.

Other species, like passenger pigeons, which once migrated in flocks so big they would darken the sky for days at a time, may have served to help keep forests healthy, and bringing them back could help with our forests.

And others, like the saber-tooth tiger, could be just for fun.