Time to Most Recent Common Ancestor, based on fossil-derived substitution rates, suggests diversification within these species (~239,600 years B.P. for G. chandleri and ~139,600 for G. gurneyi) was initiated during the early stages of glacial cooling phases [ 41].
Imagine, butter melting on hot river stones while cool glacial waters that smell like white linen flowers, citrus, crunchy nectarine and other stone fruits rush over them at pace, cleansing and cooling the stones, and leaving behind fine mineral traces of residual adrenaline and joy... well, that would be an understatement.
Estimated dates matched cold Marine Isotope Stages MISS) 8 and 12 of the Pleistocene, cool glacial periods of low sea level.
We demonstrated that during glacial ages the cool and warm temperate forests in Japan survived together, or adjacent to each other, at least in the southwestern and northeastern parts of the main islands.
These flows transported finer sediment during the cooler glacial climate, and became systematically coarser-grained as the climate warmed and dried.
During the glacial periods, climatic cooling caused southward and shifts to lower altitude in the geographic distribution of these forests.
The earliest divergence within the hermaphroditic clade is F. virsoides, currently restricted to the northern Adriatic Sea, a possible remnant from a more extensive distribution during a cooler glacial period.
Given the dramatic reduction in predicted suitable habitat at the LGM during the late Pleistocene, dispersal of P. reddelli from cave microrefugia may have occurred during warmer interglacial periods, but was arrested during cooler glacial periods, which accounted for about 80% of the Pleistocene [ 89].
Starting about 70,000 years ago, bottom waters cooled as glacial ice grew on the polar continents, as indicated by oxygen isotopes of microscopic skeletons of bottom-living organisms.
