2.5 Million-Year-Old Fossil Peaches Discovered In China

AncientPages.com - Eight well-preserved fossilized peach endocarps, or pits, dating back more than two and a half million years, have been found by scientists in southwest China.

Despite their age, the fossils appear nearly identical to modern peach pits. It's the first discovery of fossilized peaches, and it sheds new light on the evolutionary history of the fruit, which has not been well understood.

The findings, reported last week in Nature Scientific Reports, suggest that peaches evolved through natural selection well before humans domesticated the fruit.

"The peach is an important part of human history, and it's important to understand how it became what it is today," said Peter Wilf, a professor of paleobotany at Penn State and co-author of the article.

"If we know the origins of our resources we can make better use of them."

Tao Su, lead author on the paper and associate professor at Xishuangbanna Tropical Garden, discovered the fossils near his home in Kunming in southwest China when some road construction exposed a rock outcrop from the late Pliocene.

"We found these peach endocarp fossils just exposed in the strata," Su said. "It's really a fantastic finding."

The discovery provides important new evidence for the origins and evolution of the modern fruit. Peaches are widely thought to have originated in China, but the oldest evidence had been archaeological records dating back roughly 8,000 years.

Researchers discovering the first fossilized peach pits after a road construction project in Kunming, China exposed fresh rocks from the late Pliocene, more than 2.5 million years old. Several subsequent tests validated the age of the fossils. Image: Tao Su / Xishuangbanna Tropical Garden

No wild population has ever been found, and its long trade history makes tracing its beginnings difficult. At first, animals, perhaps even primates snacked on and dispersed the sweet, wild fruit.

Later, modern humans arrived and domesticated the fruit. They have created new varieties and larger sizes ever since and spread the fruit across what is now China, and far beyond.

"Is the peach we see today something that resulted from artificial breeding under agriculture since prehistory, or did it evolve under natural selection? The answer is really both," said Wilf, an associate in Penn State's Earth and Environmental Systems Institute.

The discovery provides important new evidence for the origins and evolution of the modern fruit. Peaches are widely thought to have originated in China, but the oldest evidence had been archaeological records dating back roughly 8,000 years.

The researchers say the discovery supports China being the home of the peach. The fruit remains culturally significant in the country, where it carries multiple meanings – from immortality in Taoist mythology to good fortune and beauty, Su said.

"The peach was a witness to the human colonization of China," Wilf said. "It was there before humans, and through history we adapted to it and it to us."

Su brought the fossils to Penn State and analyzed them while working there as a visiting scholar and collaborating with Wilf. Several tests confirmed that

"If you imagine the smallest commercial peach today, that's what these would look like,"Wilf said. "It's something that would have had a fleshy, edible fruit around it. It must have been delicious."

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source: PennState