When did human beings first develop the ability to speak? This remains one of the most exciting and perplexing questions for researchers of human evolution today. Speech, of course, doesn't fossilize, so scientists must hunt for indirect clues that early humans could talk. One route is through DNA. Geneticists can analyze the DNA preserved in early human remains for genes that play a known role in modern speech. Another indirect route is through the fossils themselves. Paleontologists can examine the bones of the vocal tract and compare them to modern humans and chimpanzees.
The Atapuerca Research Team, an international group of researchers, is approaching the fossil route in a new way. By analyzing fossilized ear bones from skulls found in Sima de los Huesos, a cave in northern Spain, the team is reconstructing the capacity of these 500,000-year-old ancestors to hear sounds. Their work suggests that they could hear much like we do—perhaps to register what others were saying. By studying ear bones of older extinct relatives, the team hopes to clarify how modern hearing ability evolved and the relationship between hearing capacity and the ability to speak.