Modern era Peaches go way back in time

A recent study published in Nature Scientific Publications (Su, T. et al. Peaches Preceded Humans: Fossil Evidence from SW China. Sci. Rep. 5, 16794; doi: 10.1038/srep16794, 2015) describes fossilised peach stones that were found in late Pliocene strata in south western China. The organic material had been largely replaced by iron oxides and their age was way beyond what radio carbon dating could establish; geological stratigraphy using a combination of litho-stratigraphic correlations, paleomagnetic data and regional palynology indicated they were about 2.6 million years old. The picture shows the fossilised (L) and modern (R)) endocarps.

China is thought to be the origin of the modern peach (Prunus persica, family Rosaceae), but the oldest previous evidence for them had been Chinese archaeological records dating back to 8000-7000 BP. The eight fossilised endocarps found were 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. The study suggests that China has been a critical region for peach evolution long before human presence, much less agriculture. 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.