The Jurassic Park Plot Twist that Scientists Knew All Along

Posted by Diedra Blackmill on Jul 25th 2019

The Jurassic Park Plot Twist that Scientists Knew All Along

Dr. Ian Malcolm from Jurassic Park

When told that the dinosaurs in Jurassic Park were all female so that breeding could be contained within the lab, Dr. Ian Malcolm remarks that “Life will not be contained,” and implies that it’s not impossible that the all-female dinos could, in fact, breed with each other.

Later in the film, it turns out that yes, the prehistoric reptiles did find a way to mate. Of course, the filmmakers had trouble swallowing the idea that female creatures could create life without a male, so their plot twist was some frog DNA that enabled some of the dinosaurs to change their sex.

But it turns out that this science fiction is science fact. Certain reptile species actually do exist only as females, and they reproduce more of their kind without males. Here’s what we know about the New Mexico whiptail lizard, an all-female species of lizard…

They reproduce through parthenogenesis

Parthenogenesis is a form of asexual reproduction in which the egg develops into a new individual without fertilization from a second parent. It’s actually fairly common in certain types of animals. For instance, honeybees and ants produce male drones from their unfertilized eggs.

Honeybee drone in hive

The New Mexico whiptail lizard lays up to four unfertilized eggs at a time, and they hatch to produce all female offspring. Interestingly, their offspring are not exact clones. They actually produce twice the number of chromosomes as other whiptail lizards and thus are able to produce genetically diverse offspring.

They still like to get it on

Despite reproducing with unfertilized eggs and having no males in the species, this lizard does engage in mating behaviors. New Mexico whiptails mount each other, which is believed to stimulate ovulation and egg laying.

To be clear, they don’t need to have sex with each other to produce viable eggs, but mating behavior does seem to increase egg production.

New Mexico whiptail lizard

The lizard has actually gained a nickname because of its sexual practices -- the Leaping Lesbian Lizard.

They were not bred in a lab

New Mexico whiptails are, in fact, a hybrid species that exists from crossbreeding between two other whiptail lizard species. But they were not bred in a lab. These lizards created their own hybrid species in the wild. And all the resulting lizards are female and reproduce in this asexual manner only -- they do not breed with their parent species.

They’re not the only females breeding themselves

As amazing as all this sounds, it’s actually not even that uncommon with reptiles. It turns out that other female lizards have bred through parthenogenesis as well, spontaneously creating viable offspring from unfertilized eggs.

Recent examples include a couple of Komodo dragons that have decided to become mothers all on their own.

Komodo dragon

So, as the scene in Jurassic Park wraps it up:

Dr. 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.”

Find your way over to The Tye-Dyed Iguana and check out some of the other interesting behaviors of our reptiles and amphibians.

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