I could not figure out where this was going, but it is a great puzzle, and when I got to the punchline, it was WHOA!

It is from the Karolinska Institute, and I assure you that they are extremely careful and do not say things lightly.

Even if it turns out to be incorrect, it is an extremely clever hypothesis.

http://www.scientificamerican.com/bl...-an-2010-07-02