The Origins of Peaches: Ancient Stones Reveal How Fruit was First Domesticated

Researchers are learning a bit more about the origins of a summer favorite: peaches. Scientists have taken a closer look at ancient peach stones and have found that the domestic versions of this fruit can trace their origins back at least 7,500 years.

"Previously, no one knew where peaches were domesticated," said Gary Crawford, one of the researchers, in a news release. "None of the botanical literature suggested the Yangtze Valley, although many people thought that it happened somewhere in China."

In order to get to the bottom of where peaches may have come from, the researchers used radiocarbon dating on ancient peach stones that were discovered in the Lower Yangtze River Valley. The scientists also compared the size and structure of peach stones from six sites that spanned a period of about 5,000 years. By comparing the size of the stones from each site, they found that peaches grew significantly larger over time in the Yangtze valley, which indicated that domestication was taken place.

"We're suggesting that very early on, people understood grafting and vegetative reproduction, because it sped up selection," said Crawford. "They had to have been doing such work, because seeds have a lot of genetic variability, and you don't know if a seed will produce the same fruit as the tree that produced it. It's a gamble. If they simply started grafting, it would guarantee the orchard would have the peaches they wanted."

In all, the researchers estimated that it took about 3,000 years before peaches resembled the fruit we know today. That said, radiocarbon dating revealed that domesticated peaches diverged from its wild ancestors as early as 7,500 years ago.

"The peaches we eat today didn't grow in the wild," said Crawford. "Generation after generation kept selection the peaches they enjoyed. The product went from thinly fleshed, very small fruit to what we have today. Peaches produce fruit over an extended season today but in the wild they have a short season. People must have selected not only for taste and fruit size, but for production time too."

The findings reveal a bit more about how peaches were first domesticated and changed. This, in turn, reveals that humans have been modifying their environment to suit their needs for a very long time.

The findings are published in the journal PLOS One.