I've been present for the birth of every little creature on this island. Surely not the...

John Hammond: [as they gather around a baby dinosaur hatching from its egg] I've been present for the birth of every little creature on this island. Dr. Ian Malcolm: Surely not the ones that are bred in the wild? Henry Wu: Actually they can't breed in the wild. Population control is one of our security precautions. There's no unauthorized breeding in Jurassic Park. Dr. Ian Malcolm: How do you know they can't breed? Henry Wu: Well, because all the animals in Jurassic Park are female. We've engineered them that way. [they take the baby dinosaur out of its egg. A robot arm picks up the shell out of Grant's hand and puts it back down] Dr. Ian Malcolm: But again, how do you know they're all female? Does somebody go out into the park and pull up the dinosaurs' skirts? Henry Wu: We control their chromosomes. It's really not that difficult. All vertebrate embryos are inherently female anyway, they just require an extra hormone given at the right developmental stage to make them male. We simply deny them that. Dr. Ellie Sattler: Deny them that? Dr. Ian Malcolm: John, the kind of control you're attempting simply is... it's not possible. If there is one thing the history of evolution has taught us it's that life will not be contained. Life breaks free, it expands to new territories and crashes through barriers, painfully, maybe even dangerously, but, uh... well, there it is. John Hammond: [sardonically] There it is. Henry Wu: You're implying that a group composed entirely of female animals will... breed? Dr. Ian Malcolm: No. I'm, I'm simply saying that life, uh... finds a way.