Indonesia is hugely important for understanding human migration and settlement patterns in Asia during the Early Pleistocene - a period that ended around 780,000 years ago. According to new research, Homo erectus reached the Indonesian island of Java about 1,400 kilometres west-northwest of Darwin, Australia, sometime between 1.3 million and 1.5 million years ago - around 300,000 to 500,000 years later than previously estimated. The revised time frame may settle a longstanding debate about the geographical origin of the species.
     Since 1936 over 100 different hominin fossils have been recovered from thick sedimentary layers in a large volcanic dome on the island of Java, but the complex geology has prevented anyone establishing an accepted chronology. Previous attempts to date the volcanic deposits relied solely on argon-argon dating of materials extracted from pumice. For the new study, Shuji Matsu'ura of Japan's National Museum of Nature and Science and his colleagues relied upon two different techniques - uranium-lead dating and fission-track dating - to examine the sediments in and around which the fossils were found. The new dates indicate an arrival of Homo erectus to the region around 1.3 million years ago, and no earlier than 1.45 million years ago. Later physical changes could have been the result of a major global cooling trend around 1.2 million years ago or the arrival of a separate population to the region when sea levels dropped and dry land connected the archipelago.
     Archaeological evidence suggests Homo erectus emerged in Africa. Coincidentally, new dates were very recently published for the extinction of Homo erectus both in Indonesia and the world. Homo habilis likely emerged in Asia many hundreds of thousands of years later as a sister species to Neanderthals and Denisovans.

Edited from Gizmodo (9 January 2020)