Goose bones from Stone Age China suggest the birds were being domesticated there 7000 years ago, which could mean they were domesticated before chickens
Geese may have been domesticated as early as 7000 years ago in what is now China, according to a study of preserved goose bones. That may make them the first bird to be domesticated, before chickens – although the timing of chicken domestication is uncertain.
Eda is part of a team that has excavated an archaeological site in east China called Tianluoshan, which was a Stone Age village between about 7000 and 5500 years ago. Its inhabitants “were basically hunter-gatherers”, says Eda, but they also grew rice in paddy fields.
The researchers have identified 232 goose bones at Tianluoshan and say there are multiple lines of evidence that some of the geese were at least partially domesticated.
Four of the bones belonged to immature geese that were less than 16 weeks old, with the youngest probably less than eight weeks old. This implies they must have hatched at Tianluoshan, says Eda, because they were too young to have flown in from elsewhere. However, no wild geese breed in the area today and it is unlikely they did so 7000 years ago, he says.
Some of the adult geese also seem to have been locally bred, based on the chemical make-up of their bones, which reflects the water they drank. These locally bred birds were all roughly the same size, indicating captive breeding. Finally, the researchers carbon-dated the bones and found that the locally bred geese lived about 7000 years ago.
Taken together, the findings suggest the geese were at an early stage of domestication, says Eda.
“It’s a major study in our understanding of poultry domestication,” says Ophélie Lebrasseur at the Centre for Anthropobiology and Genomics of Toulouse in France. “They’ve been very thorough.”
“The main thing that stood out for me is the fact they actually did radiocarbon dating on the bird bones,” says Julia Best at Cardiff University in the UK. This makes the dating much more reliable than if they had simply dated the surrounding sediment.
If geese were domesticated 7000 years ago, that would make them the first bird to be domesticated, says Eda. The other candidate is chickens, but there has been a dispute over when and where this first happened.
Chickens were probably domesticated from wild birds called red junglefowl, which live in southern Asia. However, genetics has complicated the story, revealing that domestic chickens subsequently interbred with other birds like the grey junglefowl.
A study published in 2014 reported that chickens were domesticated in northern China as early as 10,000 years ago, based on DNA from bones. However, it isn’t clear that red junglefowl ever lived that far north, says Lebrasseur. Furthermore, the bones weren’t directly dated and “a lot of the things they claimed were chickens were pheasants”, says Best. Firm evidence of domestic chickens only appears from around 5000 years ago, she says.
This implies geese were domesticated before chickens, says Lebrasseur. “With the evidence we currently have, I think it is true,” she says. But she adds that bird domestications are understudied compared with those of mammals like dogs and cows, so the story could well change as more evidence emerges.
It is very difficult to say why the geese were domesticated, says Eda. Meat, eggs, feathers and bone tools are all possibilities, and they may have been used in ritual ceremonies. “One of the things we see with chickens is they’re often held in high esteem when they’re first domesticated,” says Best.
Journal reference: PNAS, DOI: 10.1073/pnas.2117064119
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