The chicken mystery has nothing to do with the egg. The path that led to the Popeyes chicken sandwich was the result of a bird of the jungle coming together with humans.

The complexity of the chicken's history makes it hard to imagine a time when they weren't eating. Scientists have been reconstructing a past in which the birds, descendants of the red jungle fowl, were first viewed as marvelous and exotic and then sacrificed to ancient gods in order to become status symbols.

The location of the chicken's domestication was a topic of debate. Early domestication 8,000 or more years ago may have been in China or India. The emergence of the domestic chicken in what is now Thailand is closer to 3,500 years old than previously thought.

There is a new hypothesis proposed for how domestication happened. The advent of rice and millet cultivation in dry fields that attract the jungle fowls, brought them out of the forest into regular contact with people, according to the researchers.

The reports show how wrong our understanding of the time and place of chicken domestication was and make the case for a comprehensive re-evaluation of chickens.

The first fossils of domestic chickens were found at a stone age site in central Thailand, according to a report in the Proceedings of the National Academy of Sciences. The bones were from a long time ago.

Chickens spread west to Africa with traders from Southeast Asia and then north into Europe. The previous estimates did not hold up. Chickens first arrived in Southern Europe 2,800 years ago. It took hundreds of years for more northern areas to be reached.

The study was written by Joris Peters, an author on the paper.

Many of the samples of chicken bones used in the report had been previously studied. Three quarters of the fossils were incorrect. Chicken remnants from the 1950s had been dated to the Iron Age in some instances.

Julia Best said that with radiocarbon dating, we now have the clearest picture of our early interactions with chickens.

Comparing leg bones from an ancient chicken found in Weston Down, Britain, dated to the Middle Iron Age, left, and a modern chicken, right, radiocarbon dated to the 20th century.Credit...Jonathan Rees/Cardiff University

The methods used to treat chickens became clear. The chickens buried alone with no signs of butchery were found in Britain and European Iron Age sites.

Humans didn't start by eating birds, but by admiring them. Every human group treated the chicken with reverence as it spread around the world.

For hundreds of years chickens were celebrated and venerated, according to an author on one of the papers. We started to eat them regularly.

Evidence shows that it took a few hundred years of living with chickens to get to know them well enough to start eating them. The Romans were eating birds when they were in Britain.

Familiarity eventually bred McNuggets and a vast worldwide industry that has produced tens of billion of chickens for consumption. The business has drawn outrage from activists concerned with animal welfare and has spawned research programs aimed at removing the animal from the equation.

The articles provided a really good analysis of all the data, according to a specialist in animal genetics. The domestication of chickens was more recent and spread very rapidly around the world according to Dr. Hanotte, who was not involved in either of the new papers. We shouldn't be saying that the domestication was so old.

The authors acknowledged that further research would need to be done to confirm the domestication hypothesis. He said that children used to keep wild animals as pets. He said that it could have been a step towards domestication.

The new hypothesis was valuable because it focused on human actions and intent, rather than the other way around. He said that researchers should look for a situation in which animals derive some benefit from being associated with humans.

The pattern of dry rice cultivation in Thailand 3,500 years ago, with large productive and fallow fields and bordering thickets, may have been better for jungle fowl than the irrigation paddies common in other areas.

The relationship kicks off after that.