So, as skeptics, we evaluate evidence and come to a provisional conclusion. Sometimes, we’re told a story and we simply don’t have the evidence to come to a conclusion. This is often the case with ghost stories and alien sightings, though to date, most skeptics agree that there is a lack of sufficient evidence to support a belief in either.

What do we do if such a story is on the news? Mosnews from Russia reports that a man was taken to the emergency room complaining of severe chest pain and coughing up blood. Suspecting cancer, surgeons performed a biopsy and found not a tumor but a tree. Or a least a sapling… a young fir 5cm long was growing in the man’s lung.

That’s the story. The evidence… needs some discussion.

Is this a believable story? Can a tree grow in a man's lung?

There’s a photo on the site of some bloody tissue with what looks like a tree in it. Now, how do we know whether to believe this story or not?

We have:

A photo of tissue (lung tissue? scar tissue?) with a branch in it (grown? placed?)

A report from a source I’d never heard of before. (Discover got the story from the same source)

Alternate explanations (hoax)

We don’t have:

Motivation for a hoax

An explanation for how a tree could grow in a lung

As skeptics, what should we believe? I see belief as a gauge with neutrality in the middle, belief on the right, and disbelieft on the left. The suggestion that I drive a Honda should be found on the extreme right of the gauge, and the statement that I once swam the English channel should be to the left. Both are possible, but only one has evidence to support it.

A claim like a tree growing in a man's lung is a bit different. We also have to question whether such a thing is possible before we can decide that it really happened.

And here's the thing... we don't have enough information, I don't think. And that's where we have to excersize one of your most valuable tools in the skeptics' toolbox: the "I don't know" statement. I don't know if that really happened or not. My gauge is very slightly towards the "it happened" side.

Where does yours lie? I invite you to post a comment indicating where this story lies on the belief-o-meter for you, and why you came to that conclusion. Maybe we'll figure this out. And I urge you NOT to try to grow a tree in your lungs just to replicate this event.