If saber-toothed tigers and woolly mammoths seem like animals lost to the past, think again. The revival of extinct species, the idea behind the movie “Jurassic World,” which opens Friday, is closer to reality than some realize, said Kansas University law professor Andrew Torrance, who is researching de-extinction regulation.

“De-extinction is tantalizingly close,” he said.

Torrance, who received his doctorate in biology from Harvard University and graduated from Harvard Law School, said science fiction has a role to play when considering de-extinction laws.

“It allows us to play out what we don’t want to do in the real world,” he said.

But don’t expect to see species that have been extinct millions of years, such as dinosaurs, to be revived anytime soon. Torrance explained that CRISPR-Cas9, a recently discovered de-extinction method, requires that the species became extinct within the last 1,000 years and that it has closely related descendants that are still living.

“The more recently extinct the organism, the easier it is to revive,” he said.

For now, the idea of “Jurassic World,” the fourth in the series of films that began with “Jurassic Park,” released in 1993, remains one of science fiction.

“Rather than Jurassic Park, we’re talking about Pleistocene Park — the last age before our current era — that had animals such as the woolly mammoth, saber-toothed tiger and woolly rhinoceros,” Torrance said.

Unlike previously explored techniques of de-extinction, which used cloning, the new technique edits the genome — using proteins, chemicals and enzymes — of a living species to mirror that of its extinct ancestor, Torrance said.

“It allows you to edit genes just like you would edit a paper in (Microsoft) Word,” he said.

For instance, you take the genome of an Indian elephant, and you change a gene to make it woolly, he explained. Projects reviving the woolly mammoth and the passenger pigeon are already underway, Torrance said.

Once a species is revived, the relatives can parent the de-extinct species, and after a couple of generations the revived animals could breed with one another, Torrance said.

While dinosaurs have living descendants such as birds, alligators and crocodiles, dinosaur DNA has become fragmented in the 65 million years since their extinction, Torrance said. And obviously, relatives such as birds have become quite distinct from dinosaurs over all that time.

“There are very few birds that can scare you at the bird feeder like a T. rex would,” he said.

The Pleistocene period also had species such as the cave bear and dire wolf, which were two or three times larger than their descendants that exist today. While some of these animals might sound threatening, Torrance said, they aren’t any more of a danger than species alive today, such as the great white shark, lions or tigers.

Nevertheless, Torrance said that regulation of de-extinction should make sure that no harm is done to the animals themselves or the ecosystems into which they are reintroduced.

“This technology has a lot of potentially beneficial applications and some risks as well,” he said.

As far as the star (and danger) introduced in “Jurassic World” — a hybrid dinosaur that’s been genetically modified — Torrance said he’s intrigued by the idea.

“I’m going to see it for sure,” he said.