"The arrows show the extent of movement of Musa species by the dates shown on each map. At 30Mya the spiraling arrow indicates a time of speciation and radiation within the continental portion of SE Asia. Later they indicate its movement ‘back’ as the islands break away from the Sunda and reform in response to the advancement of the Suhel and the continent of Australia. (d) the latest period shown, 5Mya, shows the extent of this movement before the ‘glaciation’ periods of the Quaternary, 2.58 Mya, the most recent Ice Age, when the Earth began cycling in and out of these periods of the expansion of the polar ice caps toward the equatorial region and their following retreat."
http://gardenriots.com/2018/11/16/musa-sikkimensis-red-tiger-bengal-tiger-and-the-banana-story-evolution-and-cold-adaptation/-