It's funny how the birthplace of one little bean can stir up a world of passions. But when it's the soybean, maybe it's not such a shocker.
Soy plays an outsized role in human history, serving as the primary source of protein in Asia for millennia. That can slip by people in the United States, where — until very recently — the super-nutritious bean was relegated to animal feed.
But soybean pride has led to a long-running dispute between China and Korea for bragging rights to the birthplace of soy. Now new research suggests they may have to share the credit.
Historical records suggest that soy was domesticated quite recently for a major food crop, around 1,100 B.C. Bu archeologists recently examined charred beans from ancient house sites and compared them against modern beans. They say their findings suggest soy was being grown in China, Korea, and Japan as early as 5,500 years ago.
Gyoung-Ah Lee, an assistant professor at the University of Oregon, measured beans from digs from those three countries, and found the largest to be from Korean sites.
"We're not sure they are domesticated," Lee says of her beans. But she thinks the size of the beans increased through the centuries.
Lee and her colleagues are now going to use carbon dating to try to nail down the age of the beans they found to get a better handle on when soy made the leap from wild forage to crop. Their work was published in the online journal PlosOne.
In fact, the history of soy is fraught with errors and misconceptions, according to Theodore Hymowitz, a soybean geneticist at the University of Illinois. He attributes that to the fact that only recently have there been efforts to reconcile old historical texts with new archeological and botanical research. Lee's work may add one more chapter to a tale that is still being written, he says.
Now the patrimony of soy is becoming better understood, Lee says she knows why the topic inflames debate: "In China and Korea, we cannot live without beans."
The invention of agriculture is thought to have been a turning point in human evolution, making it possible to early humans to consume more calories with less effort. The invention of cooked meat may have helped fuel development of the computational power of the human brain. Surely the hardy and versatile soybean has also played at least a big a role, if not bigger.
Soy may have been late to domestication because it requires some processing to make it easy to eat, unlike rice, wheat or corn. "The soybean is rather difficult to eat as it is," says William Shurtleff, co-director of the SoyInfoCenter, a goldmine of soy history. That's partly what has lead food scientists to teach soy new tricks to appeal to tastes around the world.