New Defender's Study Bible Notes
8:17 multiply upon the earth. This is a repetition of the Edenic command to the created animal kinds (Genesis 1:20, 22). In order to do this, they must migrate from Ararat, each finding its proper ecological niche in the drastically changed and widely varied environments of the post-diluvian world. During the Ice Age following the Flood, land bridges existed across the Bering Strait from Siberia to Alaska and down the Malaysian Strait into New Guinea, facilitating such migrations. Also, Noah’s descendants certainly knew how to build and use boats, and some of the animals may well have been transported in this way, as well as on rafts of vegetation transported out to sea during river floods.