New research shows that chickens were widely domesticated in southern Central Asia from 400 BC to the Middle Ages, and their spread was likely facilitated by the ancient Silk Road. Chickens are among the most economically important animals in the world today. But the story of how they emerged and spread throughout the ancient world remains largely unclear. Recent advances in archaeological methodology have revealed that many bones once thought to be evidence of the first chickens actually belong to wild birds.

Now, in a new publication, an international team of archaeologists, historians and biomolecular scientists presents the earliest clear evidence that chickens were raised for egg production and argues that seasonal loss of egg laying was a major factor in the spread of domestic chickens. Chickens in Eurasia and northeast Africa.

Discovery and analysis

Using eggshell fragments collected from 12 archaeological sites dating back approximately 1,500 years, the researchers show that chickens were widely domesticated in Central Asia around 400 BC. BCE to 1000 CE A large number of eggshells also indicate that the birds were not in season. Researchers claim that this prolific egg-laying feature is what made domestic chickens so attractive to ancient humans.

To reach these results, the team collected tens of thousands of eggshell fragments from sites along the Silk Road’s main corridor in Central Asia. They then used a biomolecular analysis technique called ZooMS to determine the source of the eggs. Similar to genetic analysis, ZooMS can identify species from animal remains such as bone, skin and shell, but relies on protein signals rather than DNA. This makes it a faster and more cost-effective option than genetic testing.

Dr. D., a researcher at the Max Planck Institute for Geoanthropology and first author of the new paper. “This study demonstrates the potential of ZooMS to shed light on human-animal interactions in the past,” says Carly Peters.

Conclusions and implications

The identification of these shell fragments as hens and their abundance in sediment layers at each site led the researchers to an important conclusion: The birds probably lay eggs more frequently than their wild ancestors, the red jungle fowl, which nested once a year. She usually lays six eggs per clutch per year.

Head of the Domestication and Anthropogenic Evolution Research Group and principal investigator of the study, Dr. “This is the earliest evidence of seasonal spawning loss found in the archaeological record,” said Robert Spengler. “This is an important clue to better understand the interrelationship between humans and animals that led to domestication.”

Taken together, the new research offers an answer to the age-old chicken-and-egg conundrum. Evidence suggests that the ability to lay multiple eggs in Central Asia transformed the chicken into the chicken we know today, a global species of immense economic importance. The authors hope that this research will reveal the potential for new, cost-effective methods and interdisciplinary collaborations to address age-old questions about the past.