American Scientist

January-February 2024

Volume: 112 Number: 1

Mere decades ago, the idea that we could recover genomes from mammoth species was unimaginable. In 2021, three mammoth teeth found in the permafrost of Siberia, ranging in age from 700,000 to 1.2 million years old, yielded genome-wide data that added to the ancient elephantids’ evolutionary tree. Two of the teeth belonged to animals that were ancestral to the woolly mammoth (Mammuthus primigenius); the third belonged to a previously unknown species. Comparing its DNA to other mammoth genomes revealed that the Columbian mammoth (Mammuthus columbi), a well-known prehistoric denizen of the La Brea Tar Pits in California, descended from interbreeding between woolly mammoths and the newly discovered species. In “Ancient DNA,” Daniel T. Ksepka discusses how genetic material from all sorts of organisms that lived long ago can settle long-running debates and mysteries in paleontology. (Cover illustration by Beth Zaiken.)