Y-DNA P arose 46.000 BP in South Asia or Southeast Asia. Why Aboriginial Australians do not belong this Y-DNA? It is interesting that some of Oceanians and Austronesians belong this Y-DNA at low to moderate levels while Aboriginial Australians not.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4819516/
https://en.wikipedia.org/wiki/Haplogroup_P_(Y-DNA)
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4819516/
https://en.wikipedia.org/wiki/Haplogroup_P_(Y-DNA)