We have to understand that portions of Genesis are legends, rather than actual history. The flood epic is borrowed from the Sumerians, and altered slightly, as stories do change over time. It is a wrong notion to treat the flood story as though it is historical, with each of Noah's sons as the patriarch of a race.
Thus, look to science to tell you who the Crogmagon are, not the sacred texts.
True, the Bible was lifted from people in Sumeria. As well as from all of the places the Hurrians lived, and from Greece and Egypt, too. Who wrote those texts in Sumeria may have been any number of different tribes, including the tribe which wrote the Code of Hammurabi. But the Akkadians only used the script and copied that which pleased them.
The flood of Deucalion, from Samothrace, is almost the same as that given by the Welsh who came from a summer land near Constantinople. The same "mysteries" were known by both.
There is an account, in the Welsh Triads, of the bursting of Llyn Llion by which "all persons were drowned, with the exception of Dwyfan and Dwyfach, who escaped in a ship without sails, and the isle of Britain was repopulated from them."
Which may be the clue to the CroMagnon aborigines, and Cheddar man, etc. The flood can easily be the ice caps melting.
But Legend and Folk History cannot be easily dismissed simply because they weren't yet written down. Illiterate men had vastly superior memories because they needed them. The oral teachings of the Druids included Science, History and Religion. Those teachings spread to Ireland and over Gaul, and were carried [like the flight of an arrow] to the Delphic Oracle, and passed to Pythagoras [says Clement], and on to the Indians and Persians ... who each made of it what they will.
Knowledge spread in this way, from the West. ... But not every man has the same talent, and some changed it to suit their perceived needs. ... Science has the same operating principles, but instead, starting with a theory. They used to call it Philosophy, this need to define what was made and how.