The origins of the Samoans are closely studied in modern research about Polynesia in various scientific disciplines such as genetics, linguistics and anthropology. Scientific research is ongoing, although a number of different theories exist; including one proposing that the Samoans originated from Austronesian predecessors during the terminal eastward Lapita expansion period from Southeast Asia and Melanesia between 2,500 and 1,500 BCE. The Samoan origins are currently being reassessed due to new scientific evidence and carbon dating findings from 2003 and onwards.