The roots of prehistoric Australian settlers

The discusses work done by scientists in tracing the roots of the original Australian settlers . There are currently many questions still surrounding the roots of prehistoric Australian settlers . The oldest human fossils outside of Africa are found in Australia which is puzzling given the large distance between Australia and Africa . There are also two distinct sets of prehistoric people in Australia . The older finds at Lake Mungo are gracile . On the other hand , the younger finds show robust morphology . To find clues about the puzzle , the scientists used DNA analysis . They compared

the genetic sequence of the aboriginal Australians to the known world DNA tree . The samples came from mtDNA and the Y chromosome . The mtDNA samples were found to be in line with branches M and N in the global genetic tree . The Y chromosome samples were found to be in line with branches C and F . These branches place the samples with the exodus from Africa around 50-70 ,000 years ago . This tells us that prehistoric Australian settlers came from Africa 50 ,000 years ago . This is backed by the archaeological evidences . A large disparity was also found between the Australian samples and the genetic make up around the Indian Ocean . This meant that the two populations have been isolated for a long time

Two questions that I have about the include the following . First what are the details about where the samples were taken ? Did the scientists acquire the samples from today 's aboriginal Australians or from the fossil record . Secondly , why did they choose mtDNA and the Y chromosome as the genetic sequences to compare ? What is the importance of these two in determining the migratory or evolutionary path of a people ...