Solving a Peach Pit Puzzle

Just by looking at different peach pits, researchers believe they can trace the wild history of the domestic peach all to way to about 7,500 years ago. That at least according to a recent study in an international collaboration between US and Chinese researchers.

The study was recently published in the journal PLOS One, and details how the great ancestor of the peach was actually a juicy fruit from the lower Yangtze River Valley in Southern China.

So what's the big deal about peaches? Knowing where a specific crop orginates allows researchers to better understand how it evolved and how it can evolve still. The domestication of a fruit like the peach is a dramatic and keystone part its overall history.

"Previously, no one knew where peaches were domesticated," Gary Crawford, study author and researcher from the University of Toronto Mississauga, explained in a recent release. "None of the botanical literature suggested the Yangtze Valley, although many people thought that it happened somewhere in China."

If you've ever chipped a tooth by biting too deeply into one of these fuzzy fruits, you can understand just how tough peach pits can get. This allows them to be more easily made into fossilized peach stones - evidence that allowed the research team to more easily trace the fruit's ancient origins.

Peach stones are common finds at archeological sites in the Yangtze valley, so Crawford and his colleagues compared the size and structure of the fossils from six sites that spanned a period of roughly 5,000 years.

Interestingly, while the oldest stone date back about 7,500 years, the first peach stones in China most similar to modern cultivated forms are from the Liangzhu culture, which flourished 4,300 to 5300 years ago.

"We're suggesting that very early on, people understood grafting and vegetative reproduction, because it sped up selection," said Crawford.

According to the study, the uniformity of the pits as time moved on suggests this most clearly, as grafting help ensure that peach orchards produced the desired fruit.

"There is a general sense that people in the past were not as smart as we are," said Crawford. "The reality is that they were modern humans with the brain capacity and talents that we have now."

"People have been changing the environment to suit their needs for a very long time," he added. and the domestication of peaches helps us understand this."