Researchers studied an ancient forest of bald cypress trees preserved in subfossil form at the mouth of Georgia’s Altamaha River. Using radiocarbon dating and tree-ring analysis, they revealed a dramatic shift in growth patterns: around 500 A.D., these trees began growing faster – but living far shorter lives. Their average lifespan plunged from more than 470 years to just 186, coinciding with the Vandal Minimum,  a sixth century climate crisis marked by global cooling and upheaval, likely caused by volcanic eruptions and possibly even a comet impact.

Recent scholarship has concluded that Neanderthals made a second major migration from Eastern Europe to Central and Eastern Eurasia between 120,000 and 60,000 years ago. But the routes they took have long been a mystery—primarily because there are few archaeological sites connecting the two regions. In a new analysis, a team of anthropologists—using computer simulations—has offered a map of possible pathways, which concludes Neanderthals likely used river valleys as natural highways and traveled during warmer periods to move approximately 2,000 miles (3,250 km) in less than 2,000 years.