G.A., J.Y.C., J.E.C., T.H.H., E.M., S.P., S.R., S.Sc., S.Su. and J.L.W. contributed equally and are listed alphabetically in the author list; A.A., C.Ba., I.D., A.E., A.Mar., I.M. and I.P. contributed equally and are listed alphabetically in the author list; T.S.K., I.P.L., J.V.M.-M., S.N., F.R., M.Si. and Y.X. contributed equally and are listed alphabetically in the author list. E.W. and D.M.L. initially conceived and headed the project. L.E. led the genetic load and the SFS-based demographic analyses. M.S.S. headed the research at the Wellcome Trust Sanger Institute. A.-S.M. planned and coordinated the genetic analyses and the sequencing of the Aboriginal Australian genomes. C.M., J.L.W., T.H.H., P.F.C., W.C., G.F., D.I., B.L., A.L., P.J.M., L.M., D.R., T.W., C.W., J.D., M.C.W. and E.W. collaborated with local groups to collect Aboriginal Australian samples. N.B., P.G., G.K., M.L., A.J.M., A.B.M., W.P., F.-X.R., P.S., M.G.T. and S.J.O. collaborated with local groups to collect Papuan samples. S.E. collaborated with local groups to collect the Rapanui sample. A.Mar. extracted DNA for the Aboriginal Australian genomes. M.S.S., A.B. and C.T.-S. coordinated the design and sequencing of the Papuan genomes. O.L., V.C.S., I.A., A.-S.M., A.B., G.A., J.Y.C., J.E.C., T.H.H., E.M., S.P., S.R., S.Sc., S.Su., J.L.W., A.A., C.Ba., I.D., A.E., A.Man., I.M., I.P., T.S.K., I.P.L., J.V.M.-M., S.N., F.R., M.Si., F.A., S.B., L.E., J.D.W. and T.M. analysed genetic data. C.Bo. collected and analysed linguistic data. L.E., E.W., D.M.L., Y.X., M.E.P., C.T.-S., R.D., M.S.S., A.Man., M.H.S., T.M., M.St. and R.N. supervised genetic analyses. M.C.W., C.M., W.C., G.F., D.I., B.L., A.L., P.J.M., L.M., D.R., T.W., C.W., E.A.M.-S., M.M., M.E.P., S.J.O., J.D., A.B.M., R.A.F. and M.M.L. provided archaeological, anthropological and historical context. A.-S.M., V.C.S., O.L., I.A., A.B., M.M.L., R.N., L.E., D.M.L. and E.W. wrote the manuscript with critical input from G.A., T.H.H., E.M., S.Sc., S.Su., J.L.W., C.Ba., A.E., I.P., E.A.M.-S., M.S.S., S.J.O., C.T.-S., R.D., M.G.T., J.D., A.Man., M.H.S., R.A.F., C.Bo., J.D.W., T.M., M.St. and all other coauthors. A.-S.M., V.C.S., O.L., I.A. and A.B. revised and compiled the
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