A team of paleontologists has found 8 fossil peach endocarps, or pits, in the late Pliocene Ciying Formation in Kunming, China, whose morphological characters are identical to modern peaches. The discovery provides important evidence for the origins and evolution of the modern fruit.
Homo erectus may have enjoyed Prunus kunmingensis peaches. Image credit: Rebecca Wilf.
Peach (Prunus persica) is a universally known tree fruit with an annual production near 20 million tons.
This fruit is widely thought to have originated in China, but the oldest evidence had been archeological records dating back 7,000-8,000 years.
According to the team, led by Dr Tao Su of Xishuangbanna Tropical Garden and the Nanjing Institute of Geology and Paleontology, the word ‘peach’ has long appeared in Chinese literature, e.g., the books Shi-Jing (1,100 – 600 BC) and Shi-Ji (1st century BC).
“Despite the significant fossil record of Rosaceae and the genus Prunus, the origins of the peach and its unique features remain unknown,” the researchers said.
“No wild population has been confirmed, and the long history of trade and complex genomics of peach cultivars present considerable obstacles.”
Prof. Peter Wilf, a team member and a paleontologist at Pennsylvania State University, added: “the peach is an important part of human history, and it’s important to understand how it became what it is today.”
“If we know the origins of our resources we can make better use of them.”
Dr Su, Prof. Wilf and their colleagues discovered the fossilized peaches in Kunming, Yunnan, southwestern China, when some road construction exposed a rock outcrop from the late Pliocene.
“We found these peach endocarp fossils just exposed in the strata. It is really a fantastic finding,” they said.
The scientists identified the fossils, documented them as a new species of the genus Prunus, and named it P. kunmingensis.
Morphological comparison of endocarps between Prunus kunmingensis and modern peach (Prunus persica). Scale bar – 1 cm. Image credit: Tao Su et al.
It’s the first discovery of fossilized peaches, and it supports China being the home of the peach.
“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,” Prof. Wilf said.
“Peaches evolved their modern morphology under natural selection, presumably involving large, frugivorous mammals such as primates. Much later, peach size and variety increased through domestication and breeding,” the scientists explained.
The findings were published November 26 in the journal Scientific Reports.
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Tao Su et al. 2015. Peaches Preceded Humans: Fossil Evidence from SW China. Scientific Reports 5, article number: 16794; doi: 10.1038/srep16794
