We are into a cycle where we have Ice for 100,000 years and an interglacial of just over 10,000 years.
Within the period of Ice there are smaller warm spells called Interstadials.
Our African ancestors were still pygmy people on the SW coast ~ and may well have lived furthest South long enough to have been selected for a variety of changes necessary for life in Europe later on after their big migration.
Thanks muawiyah.