Ancient peach pits unearthed in China are revealing a little more on the evolution of the fruit which has had scientists wondering for a long time.
The fortuitous finding of the ancient peach pits occurred as a construction team was preparing to upgrade a road in Kunming, Yunnan. Professor Tao Su with the Xishuangbanna Tropical Botanical Garden happened to supervise the works as the construction team unearthed a layer of rock dating to the late Pliocene near a familiar sight to the professor: a bus stop.
A common place like this had held the ancient peach pits for millions of years. More precisely, deep within the Pliocene rock layers the ancient peach pits had been buried for two and a half million years.
The ancient peach pits unearthed in China look strikingly as the peach pits we leave behind today after enjoying the juicy refreshing fruit. Professor Tao Su and Professor Peter Wilf with the Pennsylvania State University in collaboration with their colleagues dedicated a study to the ancient peach pits to gather more clues on the evolution of the fruit, a historic puzzle which has kept scientists in the dark until now. The study is available for consultation in the Scientific Reports journal.
For a long while it has been speculated that the origin of the fruit is in China. However, there was little evidence to support the speculation. The only other archeological findings or peach endocarps or peach pits were only dated to 8,000 years ago. The ancient peach pits unearthed in China add relevant new evidence to support the hypothesis. So how did peaches look in the late Pliocene?
According to the researchers:
“The fossils are identical to modern peach endocarps, including size comparable to smaller modern varieties, a single seed, a deep dorsal groove, and presence of deep pits and furrows”.
Who then could have enjoyed the fruits more than two million years ago? There is little evidence to understand this piece of the puzzle. However, to avoid ambiguities, the researchers called the peaches of the late Pliocene Prunus kunmingensis, a new species belonging to the genus Prunus.
The morphological traits of the ancient peach pits could not be used to recreate the entire plant piece by piece. Nonetheless, they yielded sufficient proof to support the hypothesis that the worldwide known Prunus persica actually originated in China, stemming from the Prunus kunmingensis.
Since the late Pliocene, the fruit had evolved under natural selection according to the research team. As primates and animals later snacked on the fruits, seeds were dispersed on a wider and wider area. Breeding and domestication brought their contribution to the widespread geographical area of peach trees.
Modern peaches come in a many varieties and sizes. Based on an analysis of the ancient peach pits, the researchers concluded that the peaches of the Prunus kunmingensis species would have been approximately 2.05 inches in diameter.
Photo Credits: i4u.com