It's the pits: Ancient peach stones offer clues to fruit's origins

It's the pits: Ancient peach stones offer clues to fruit's origins
Different sizes of peach stones examined in study. Credit: Courtesy of Gary Crawford

Anyone who enjoys biting into a sweet, fleshy peach can now give thanks to the people who first began domesticating this fruit: Chinese farmers who lived 7,500 years ago.

In a study published today in PLOS ONE, Gary Crawford, a U of T Mississauga anthropology professor, and two Chinese colleagues propose that the domestic peaches enjoyed worldwide today can trace their ancestry back at least 7,500 years ago to the lower Yangtze River Valley in Southern China, not far from Shanghai. The study, headed by Yunfei Zheng from the Zhejiang Institute of Archeology in China's Zhejiang Province, was done in collaboration with Crawford and X. Chen, another researcher at the Zhejang Institute.

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

Radiocarbon dating of ancient peach stones (pits) discovered in the Lower Yangtze River Valley indicates that the peach seems to have been diverged from its wild ancestors as early as 7,500 years ago.

Archeologists have a good understanding of domestication – conscious breeding for traits preferred by people– of annual plants such as grains (rice, wheat, etc.), but the role of trees in early farming and how trees were domesticated is not well documented. Unlike most trees, the peach matures very quickly, producing within two to three years, so selection for desirable traits could become apparent relatively quickly. The problem that Crawford and his colleagues faced was how to recognize the selection process in the archeological record.

Peach stones are well represented at archeological sites in the Yangtze valley, so they compared the size and structure of the stones from six sites that spanned a period of roughly 5,000 years. By comparing the size of the stones from each site, they were able to discern peaches growing significantly larger over time in the Yangtze valley, demonstrating that domestication was taking place. The first peach stones in China most similar to modern cultivated forms are from the Liangzhu culture, which flourished 4,300 to 5300 years ago.

"We're suggesting that very early on, people understood grafting and vegetative reproduction, because it sped up selection," Crawford said. "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."

Crawford and his colleagues think that it took about 3,000 years before the domesticated peach resembled the fruit we know today.

"The peaches we eat today didn't grow in the wild," Crawford added. "Generation after generation kept selecting 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."

Discovering more about the origins of domesticated peaches tells us more about our human ancestors, too, Crawford noted.

Crops such as domesticated peaches indicate that early people weren't passive in dealing with the environment. Not only did they understand grain production, but the woodlands and certain trees were being manipulated early on.

"There is a general sense that people in the past were not as smart as we are," said Crawford. "The reality is that they were modern humans with the brain capacity and talents that we have now.

"People have been changing the environment to suit their needs for a very long time, and the domestication of helps us understand this."


Explore further

White Delight: New peach varieties released for warmer climates

Journal information: PLoS ONE

Citation: It's the pits: Ancient peach stones offer clues to fruit's origins (2014, September 6) retrieved 25 May 2019 from https://phys.org/news/2014-09-pits-ancient-peach-stones-clues.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
0 shares

Feedback to editors

User comments

Sep 06, 2014
"There is a general sense that people in the past were not as smart as we are," said Crawford. "The reality is that they were modern humans with the brain capacity and talents that we have now".

This needs to be repeated every time someone like buadrunner spouts off with his nonsense about ETs and ancient cultures.


Sep 06, 2014
@Vietvet
I couldn't agree more.

Sep 06, 2014
And where are those Creationists? What, 7500 years ago? Why, that just can't be! Or maybe they'll tell us that this was the original tree of the knowledge of good and evil. Now, if only we can find that talking snake....

Sep 06, 2014
Now, if only we can find that talking snake....
@PhotonX
love the post! sarcastic hyperbole rocks.
here is a thought about that whole creationist logic thingy...
if there was a talking snake and angels
and there is no evolution per their claims denouncing it...

where is the evidence of the talking snakes and angels now?

Or that whole garden and tree of knowledge... or the tree of life... :-D

Like Vietvet points out... they were modern humans

it's like saying our grandfathers would not be able to live in today's world had they been born in the past 20 years rather than 95 years ago


NOM
Sep 06, 2014
and there is no evolution per their claims denouncing it...

And wasn't one of these creationists recently demanding evidence of evolution? The domestication of wild fruit is exactly that.

Sep 06, 2014
and there is no evolution per their claims denouncing it...

And wasn't one of these creationists recently demanding evidence of evolution? The domestication of wild fruit is exactly that.

@NOM

I will give you the honors of sharing this link with him then! :-)
VERY GOOD POINT as well
THANKS

Sep 06, 2014
@vercle
The variables in carbon 14 dating are well known, your comments show your creationist/young earth bias.

Your comments lack integrity because they are not based on science but your fundamentalist religious beliefs.

You are a dishonest person and for that you deserve all the ridicule that comes your way.

Sep 06, 2014
verkle muttered immense ignorance
Given these many unknowns, it is difficult to use this as accurate dating for things more than 2000-3000 years old
There many other radioactive isotope datings besides Carbon, also issues of nucleotides & connections with supernova remnants & eg ro some origin like a big bang...

Ok verkle, U & others can claim this is from 'the god', well why did it punish all creation by the choice of a woman - assuming he CAN'T predict she'd be manipulated, so she was set up ?

Raises logic problem for Anyone who "believes" old testament because:-

1. God punished eve/adam for making a mistake re choice of the fruit, so
2. They became mortal & their children would equally suffer thereafter
3. Is this sane ? ie. If your wife did something wrong you harm her daughter ?

The logic problem arises in that god made the punishment, ie He/she/it decided how badly all others (including animals?)

So to alleviate any suffering, is against god then ?

Doctors r evil ?

Sep 06, 2014
Given these many unknowns, it is difficult to use this as accurate dating for things more than 2000-3000 years old
@verkle
if you are working under the assumption that carbon dating has not progressed since first used in 1940, you may have slight credibility...
however, as you can see here: https://en.wikipe...n_dating
it has progressed CONSIDERABLY since 1940, therefore your comments are nothing more than smoke and bad wind (try Bean-o)

your comment is also an attempt to change the topic and redirect from your colossal errors in logic, science and reality above

you have NOT refuted anything with science, and you are still not factually correct in your assumptions regarding science
THEREFORE you are again posting a blatant known fallacy -otherwise known as a LIE
which is considered against the dogma of almost every known religion
which makes you hypocritical

Stick to your faith and leave your religious stupidity for religious forums
not science

Sep 06, 2014
@verkel
I see you're still posting drivel and people are still deriding you and I let me guess, you're still astounded that they do.
A smarter person would learn from the experience.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more