Ancient DNA Surfaces on Cave Walls, Illuminating Ice Age Humans

Researchers analyzing cave-wall samples from Altamira, Escoural, and Covarrón found ancient human DNA preserved on pigment crusts and even unpigmented areas. Of 54 samples, five yielded authentic mitochondrial DNA (three women, one man, one unidentified), with some nuclear DNA linking individuals to Western Hunter-Gatherers. Preservation was rare (1 of 24 panels), suggesting cave walls can archive genetic traces of prehistoric visitors and offering a new, noninvasive way to study who touched the walls and how far Ice Age people ventured.