In the book, scientists engineer the dinos to be missing an amino acid and they only raised one sex of dinos so they couldn't reproduce on their own.

Over the course of the disaster it's revealed that the amphibian DNA used to fill in missing gaps let them change sex and so reproduce, and that the dinos found a natural source of the missing protein.

That's the twist at the end is that the Nedry situation and the hurricane just revealed that the park had already failed to contain the dinosaurs. So without Nedry they just would have gone on longer without knowing the dinosaurs were already loose. The park was ready to open soon so probably they wouldn't even have resurrected any new species.