Recent analysis of genome-wide data from 164 ancient and 112 modern individuals revealed five successive streams of migration (M1-M5) into various parts of Micronesia. The most ancient of these, M1, involved seagoing ancestors of the Chamoru of the Mariana Islands who are distinguished from people in M2-M5 by a prehistoric absence of Papuan ancestry. The data separate M1 from M2, who were ancestral to present day Palauans, and from participants in the "Lapita expansion" into the southwest Pacific (M3), and later from two migratory streams from northern Papua New Guinea/Admiralties into the high islands of the Carolines (M4), and most recently, immigration from Polynesia (M5) into the Polynesian Outliers. In this paper we discuss some of the anthropological implications of these findings.