An interdisciplinary study has determined that modern chickens only developed several of their most prized domestic traits within the last 1,000 years. A British team made up of archaeologists, geneticists, statisticians, and historians made the discovery by sequencing ancient DNA from chicken bone samples collected at archaeological sites across Europe, whose dates range from Roman times through the postmedieval period, and creating a model that pinpoints when specific chicken genes began to change. Though humans first domesticated jungle fowl in Asia around 6,000 years ago, it was only in the High Middle Ages that chickens began to consistently display both a lack of aggression and the capacity to lay eggs more regularly. According to Liisa Loog of the University of Oxford, a lead author of the study, one individual genetic variant may be responsible. “This particular mutation we’re looking at has been shown in modern chickens to both make them friendlier and enable them to lay eggs earlier on in the breeding season,” she says.

Humans, of course, favored these cooperative chickens and, unwittingly, exerted selective pressure that perpetuated their genes. To understand why chickens evolved so rapidly, Loog and her colleagues point to the spread of Christianity throughout Europe a thousand years ago, when dogmatic prohibitions on the consumption of four-legged animals and fasting rituals may have increased the demand for poultry. “Every time we see a transformation like this we just assume that it must have taken a very long time to happen,” says Loog. Instead, it seems that a widespread and rapid shift in the dietary behavior of large populations accelerated the kind of evolutionary change in chickens that is often imagined to occur over millennia. Loog explains, “It kind of shows you don’t really need to know much about genetics to make genetically modified organisms.”

New radiocarbon dates show that a mask discovered in a valley in northwest Argentina is the oldest worked copper artifact ever found in the Andes. The 3,000-year-old mask, which depicts a stylized human face, was discovered in the grave of a man who lived at a time when Andean peoples were first beginning to practice agriculture. Scholars had generally believed metallurgy in the New World was first developed in Peru and then spread to the rest of South America. But the mask challenges that assumption, says University of Buenos Aires archaeologist Leticia Inés Cortés, who led the team that studied the artifact. “Since complex societies later emerged in what is now Peru, there is a tendency to assume that all technological innovations did too,” says Cortés. “The mask shows that there was not one place for innovation in metalworking, but many, including this region of the southern Andes.”

In 2015, French officials announced the discovery of an exceptional Celtic burial located in Lavau, Champagne. The fifth-century B.C. tomb contained a wealthy individual—likely a prince—surrounded by a luxurious assemblage of personal items and drinking vessels (“Top 10 Discoveries: Tomb of a Highborn Celt,” January/February 2016). Now, two years later, laboratory analysis of those artifacts has begun to reveal just how truly extraordinary the burial is. Scientists from the Center for Research and Restoration of the Museums of France recently examined objects from the grave using a host of modern techniques, including X-ray tomography and radiography, 3-D imaging, and chemical analysis—a rare opportunity to employ the newest technologies on objects taken recently from the ground, as opposed to those that have been deteriorating in storerooms for decades, or those that have already undergone conservation procedures. Radiography showed that the prince’s belt was embroidered with fine silver threads that formed a continuous frieze of Celtic motifs, the only one of its kind ever discovered. His knife sheath was decorated with bronze thread. Closer examination of the metal vessels revealed their remarkable quality and the skill of the ancient metallurgists, who had mastered the smelting and engraving process. High-resolution 3-D scanning was even able to identify signs of subtle wear on a gold torc caused by its contact with human skin or clothing.