While the streets, houses, and shops of ancient Herculaneum were preserved to a remarkable degree by the eruption of Mount Vesuvius in A.D. 79, its vibrant frescoes have suffered a tremendous toll in the years since they were first exposed. By using a new portable X-ray fluorescence (XRF) device called Elio, chemist Eleonora Del Federico of the Pratt Institute has been able to see behind the damage to the surface of a painting excavated in the House of the Mosaic Atrium 70 years ago. “Using this device we can see a complex and sophisticated painting technique with details not visible to the naked eye today,” says Del Federico. But it was the “iron map”—XRF shows researchers the elemental composition of artifacts and how the elements are distributed within the object—that Del Federico says “blew her mind.” She says, “The iron map shows not only a beautiful woman, with detail, but also reveals her thoughtful expression and, for me, her humanity. Looking at the iron map, to me, is like looking into this woman’s soul.”

Analysis of charcoal from Scotland’s monastery island of Iona has concluded that a wooden hut often associated with Saint Columba indeed dates to his lifetime in the late sixth century. Columba, an Irish abbot and missionary, was a dominant force in the spread of Christianity throughout Scotland. He founded the monastery on Iona, which stood as a bastion of literacy and scholarship for centuries and attracted legions of pilgrims until Catholic Mass was made illegal during the Reformation in the sixteenth century. Originally uncovered in the 1950s by archaeologists Charles Thomas, Peter Fowler, and Elizabeth Fowler, the charcoal comes from an ash layer of Tórr an Abba, or “Mound of the Abbot,” on the monastery’s grounds. While the three scholars believed they had found evidence of Columba’s cell, which appears to have been turned into a monument not long after his death in 597, they were never able to prove it.

After storing the Iona samples for years in his own garage, Thomas bequeathed them to Historic Environment Scotland, which teamed up with archaeologists from the University of Glasgow to radiocarbon date the material and revisit the site. “What they excavated in the 1950s was a hut that didn’t look like it had many stages, perhaps one or two constructions,” says lead archaeologist Adrián Maldonado. “At some point it burned down and that’s the charcoal we were able to date.” The latest possible date for the charcoal is A.D. 650, making it likely that Columba, and perhaps later abbots too, used the cell.

In recent years, scientists have determined that early humans interbred with other hominin species, such as Neanderthals and Denisovans, by comparing the genomes of present-day humans with DNA taken from hominin fossils. Now, however, evidence of interbreeding has been found based on analysis of human genomes drawn from people currently living around the world. Specifically, researchers have focused on a gene called MUC7, which codes for a protein found in saliva.

A team led by Omer Gokcumen and Stefan Ruhl of the State University of New York at Buffalo studied how MUC7 varied in 2,500 present-day human genomes. To their surprise, it took a dramatically different form in around 5 percent of people from sub-Saharan Africa. The most likely explanation, the researchers concluded, was that some 150,000 to 200,000 years ago, a group of humans in Africa interbred with an unknown hominin species, whose version of MUC7 has been passed down to people living there today.

Although this interbreeding took place before humans left Africa, the mystery hominin’s genes appear not to have been carried by those who left the continent. Based on known rates of genetic mutation, the hominin appears to have diverged from modern humans around one to two million years ago, and the researchers believe it was probably similar to other hominin species of the era, such as Homo erectus, Neanderthals, and Denisovans, in terms of brainpower and technological skill.

As genomic techniques grow more refined, Gokcumen believes we will detect more and more instances in which early humans interbred with other hominin species. “We are seeing that there were multiple humanlike groups that modern humans absorbed rather than replaced,” he says. “We are only seeing them now because we are able to look at entire genomes.”