There’s a tree so endangered that it’s endemic to only one specific place in the entire world.

That tree is the Wollemi pine, and it’s  found in a top-secret sandstone canyon somewhere in Australia’s  enormous Wollemi National Park. Its nickname is the dinosaur tree, and  they’ve been around for millions of years.

And while there’s only a hundred of  these living fossils out in nature, researchers are working to change that. With any luck, you might even be  seeing them in your local garden store. [♪ INTRO] Wollemi pines are these funky  looking trees with wide needles that give them a fern-like  appearance, red, bumpy bark, and multiple trunks sprouting from one location. So they’re more like a lumpy bush than  your typical tree… whatever that means.

They can live for hundreds to  thousands of years…we think. See, it’s hard to tell exactly how old they are. Counting their growth rings is tricky  when they have multiple trunks, since you’d need to figure  out which is the oldest.

Good luck with that. And part of why we don’t know  a ton about them is that, until recently, we didn’t  know the world still had any. Researchers thought that the Wollemi pine  went extinct around 2 million years ago.

That is, until 1994 when an Australian park ranger accidentally stumbled upon a  whole canyon filled with them. At the time, this discovery was coined as one of the greatest botanical discoveries in 100 years. It’s the coelacanth of trees, if you will.

Wollemi pines belong to a family  of trees that were most abundant during the Cretaceous Period,  when dinosaurs roamed the Earth. Studying this tree family’s history  has given scientists a peek into past climates and their impact on  the vegetation during the time. This, combined with newer research  on the Wollemi pine’s genome, has helped to piece together  the rise and fall of this tree over the millions of years they’ve been around.

Ancient Wollemi pine populations  had their heyday between eight and six million years ago thanks  to a unique shift in the global climate. Some 30 million years prior  to that, the supercontinent Gondwana had broken apart. This breakup is what pushed the  continents of the southern hemisphere into roughly the places they are today.

As a part of this breakup, the Sahul shelf, part of Australia’s continental  shelf, detached and moved northward. This process alone took millions of years and established the currents  that flow around Antarctica. These new currents brought cooler, drier climates, leading to temperate rainforests where  Wollemi pines thrived far beyond Australia.

But as time marched on, the climate  continued to dry out even more, which became too much for the Wollemi pine. It was so dry during the Pliocene  Epoch that they were restricted to just a narrow region in  Australia that had enough rainfall to support their water needs. And they’ve stayed there ever since.

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You can invest in your mind and get  Imprint using the link in the description or by scanning the QR code. As a SciShow viewer, you get  20% off an annual membership on top of a 7-day free trial. The modern-day Wollemi pine doesn’t just look like the trees hanging around during the Cretaceous.

Even the tree’s genome is  similar to its ancestors, earning it the living fossil nickname. These trees don’t end up  exchanging much genetic material, because they reproduce by sending out new shoots from the original plant that are  genetically identical to the original stem. It’s hard to be genetically diverse when your reproductive strategy is to  essentially copy and paste yourself.

Wollemi pines do also produce seeds, but  they take a really long time to develop. However, millions of years ago, when  these trees were having a moment, researchers believe that making seeds  was their primary reproductive strategy, not cloning like it is today. Sexual reproduction would have added  a lot more variety to their genome.

Unfortunately, it can also lead  to errors, like transposons, which are jumping genes that  randomly insert themselves into the genetic code and cause errors. Researchers have found evidence of  ancient transposons in the Wollemi pine’s genome that would have introduced  genetic instability into the population. So, facing both the pressure of  climate change and an increase in genetic mutations, Wollemi pines probably  shifted to cloning to limit the spread of harmful mutations that would whittle  down their populations even more.

Cloning is also a much faster process, and this strategy may be what kept  them from going extinct altogether. Today, there are less than 100 adult Wollemi  pines left in the wild and their location, while known to be somewhere  in Wollemi National Park, is a heavily guarded secret. This tiny remaining population  faces a looming threat of extinction from both wildfires and a destructive fungus.

Recent genetic analysis reveals that the  Wollemi pines are highly vulnerable to dieback caused by a water mold that  spreads across their wide needles. This mold can get tracked in by hikers, which is all the more reason  to keep the location hidden. And in 2020, these trees faced a  totally different threat when a wildfire came dangerously close to the  canyon where they’re sequestered.

Thankfully, firefighters stopped the  blaze before it wiped out the trees. But it’s threats like these that have inspired  researchers to try to protect the tree by cloning it, so they can continue  to study the Wollemi pine in the lab. Horticulturalists are even  cultivating tissue samples so that gardeners everywhere can grow one of these trees.

So, while a wild Wollemi pine  is almost impossible to find, you may be able to purchase them at your  local garden center and grow it at home! I feel like having a dinosaur tree in  your backyard would be extremely cool, even if it’s just for the name alone. So that’s the story of the rise and  fall of the world’s rarest tree, from widespread to utterly isolated.

And maybe with the help of  some crafty horticulturalists, back to worldwide once again. [♪ OUTRO]