Today’s Wonder of the Day was inspired by Raegan. Raegan Wonders, “What are other endangered species?” Thanks for WONDERing with us, Raegan!

Have you made any plans yet for the zombie apocalypse? If not, what are you waiting for? If popular television shows and movies have taught us anything over the last decade, it's that one day most of humanity will be wiped out and those of us that survive will have to battle for our lives against hordes of zombies.

If that sounds too much like the stuff of science fiction, you might not be too worried about zombies. Threats to human extinction do exist, though, even if the end of the world doesn't contain zombie armies.

With a current population of over seven billion human beings, it's hard to imagine Earth existing without humans on it. Can you imagine what that would be like? How lonely would it be to exist as the last, solitary, lone human being on Earth?

If you can imagine what that might feel like, then you can get a sense of what it must be like to be Encephalartos woodii. More commonly known as Wood's Cycad, it's considered by many to be the world's loneliest plant.

And how strange that is! Nearly three hundred million years ago, cycads made up around 20% of the world's plants. These small trees topped with palm-like fronds were everywhere. Dinosaurs roamed among them, and some dinosaurs probably relied upon them for food.

Cycads survived the extinction event that killed the dinosaurs. They also survived five different ice ages. Over time, however, other trees and vegetation took over. Cycads diminished until, in the case of Wood's Cycad, there was just one left on Earth.

Wood's Cycad was discovered in 1895 by botanist John Medley Wood. He found it while exploring the Ngoye Forest in Zululand (modern-day South Africa). Sitting on a steep slope at the edge of the woods, the tree stood out because it looked quite different than the other trees in the area.

It was eventually named Encephalartos woodii after Wood. Wood knew he had found a rare wild example of an ancient cycad species. He collected several offsets and a couple stems of the plant and sent them to a few botanical gardens around the world.

It was only later that the true rarity of his discovery was realized. Despite diligent searching by scientists over the last century, no other wild example of Wood's Cycad has ever been found.

The original tree found by Wood eventually died. In a sense, though, it lives on in its clones, because its offsets and stems have created new Wood's Cycads in botanical gardens around the world.

Continued cloning is the only way to preserve the species today. This is because the Wood's Cycad is a dioecious species. That means it has distinct male and female organisms.

One plant can't fertilize itself. Without a wild Wood's Cycad of the female variety, the plant will never be able to reproduce naturally. To date, none has ever been found, making the Wood's Cycad one lonely bachelor.

Will Wood's Cycad remain a living fossil, frozen genetically forever in time? Maybe. The chance still exists that a female plant might be found in the wild. In the meantime, scientists are working to solve the problem themselves.

Some scientists have used pollen from Wood's Cycad to fertilize the seeds of Encephalartos natalensis, a closely-related species. Through a process known as "back-crossing," they hope to one day create a plant that will nearly duplicate a female Wood's Cycad, allowing the species to reproduce "naturally" again.

Wonder What's Next?

Tomorrow’s Wonder of the Day features both dungeons and dragons!