Maddie Bender in Earth Magazine:
Neanderthals disappeared from Europe roughly 40,000 years ago, and scientists are still trying to figure out why. Did disease, climate change or competition with modern humans — or maybe a combination of all three — do them in? In a recent study, researchers offer new evidence from Eastern Europe that climate change was a major player in the Neanderthals’ disappearance. Our knowledge of Eastern Europe’s climate late in the Paleolithic has been informed largely by sediment cores from the Black Sea. However, it’s not clear that these marine records accurately represent conditions on land at the time, says Michael Staubwasser, a geochemist at the University of Cologne in Germany and lead author of the new study, published in Proceedings of the National Academy of Sciences (PNAS).
To study Eastern Europe’s paleoclimate in more detail, Staubwasser and his colleagues analyzed cave deposits called speleothems from two caves in the Carpathian Mountains of Romania. Ratios of carbon and oxygen isotopes preserved in successive layers of the speleothems offer records of regional temperatures and precipitation during the Paleolithic. The team identified two periods of cooling resulting in temperature drops of 1 to 1.5 degrees Celsius each about 44,000 and 40,000 years ago. The timing of these cooling periods matched with long absences of Neanderthal tools in the archaeological record. Based on these so-called sterile layers, the researchers suggested that the cold might have caused the Neanderthals’ disappearance from Europe.