CANBERRA, AUSTRALIA—According to a statement released by Australian National University, a study of artifacts unearthed in caves on the northeastern Indonesian island of Obi suggests that seafaring people reached the island at least 18,000 years ago, when the climate was drier and cooler, and sea levels were lower, making the island much larger than it is today. Among the objects recovered from the caves were 11,700-year-old stone axes, and fragments of 14,000-year-old axes made of clam shells. Similar objects were traditionally used by people in the region to create dugout canoes. Researchers led by Shimona Kealy and Sue O’Connor suggest that these tools may have been used by early island inhabitants for clearing forest undergrowth and carving dugout canoes for transport between islands. Other objects that indicate that Obi’s residents enjoyed contact with people from other islands include pieces of obsidian, since there is no known source of volcanic glass on the island, and shell beads that are similar to those found on islands to the south. Obi is thought to have been abandoned about 8,000 years ago, perhaps because the jungle undergrowth became too thick to manage for hunting and other activities as the climate warmed. Read the original scholarly article about this research in PLOS ONE. To read about the world's oldest known cave art that was discovered on the Indonesian island of Sulawesi, go to "Shock of the Old."