Some 2,400 years ago, Hippocrates, an ancient Greek scholar of medicine, sat down with his young pupils under the shade of a plane tree in Kos, Greece -- or so legend has it. Today, DNA researchers say they have identified the genetic fingerprint of that tree that served as one of medicine's earliest classrooms.
The original tree died hundreds of years ago, but in its place is a tree planted in 1776 that is thought to be a descendant of the original tree. Cuttings from this descendant have been presented as gifts to libraries, colleges and medical institutions around the world.
One of these cuttings was planted at the National Library of Medicine near Washington, D.C. and it's this specimen that was used by researchers at the Smithsonian's Laboratories of Analytical Biology to identify the famous tree's genetic fingerprint, or DNA barcode.
The effort was part of the Barcode of Life Project, which has banked the genetic blueprints of more than 200,000 species toward its goal of logging DNA barcodes from every species on Earth.
"I'm sure that Hippocrates would have been fascinated by the DNA Barcode Project and I think he would have been very excited about how DNA comparison and other modern methods are being used to better understand and ultimately treat human disease," Dr. David Lipman, director of the National Library of Medicine's National Center for Biotechnology Information, told BBC News.
Hippocrates was an ancient Greek physician and is considered the father of western medicine. He is credited with being the first to believe that diseases were caused naturally, not because of superstition and gods.
Hippocrates may now be best known for the oath named after him, which is still commonly recited today by physicians and other health care workers as a pledge to practice medicine honestly.
There's no way to guarantee that the DNA barcode created by the Smithsonian researchers is a true match to the very tree that Hippocrates taught under -- or that the famous Greek physician even taught medicine under a plane tree in Kos. But if the legends are true, then science now has the genetic code to seal the tree's place in history.