I've also read recent articles that place the Biblical accounts of Noah as being based upon legends of the ancient Babylonians. Those accounts predate the Bible by several thousand years, and would have been available to the Jews who were taken to Babylon.
I think the scholarly consensus is that the Noah's ark story was written before the exile.
The cognate languages for Sumerian are, interestingly enough Saami (found in Northern Finland, Norway, Sweden and Russia), an ancient non-Han written language found in China, and the ONLY American Indian language to be successfully linked to an Old World language.
These languages in turn may be related to the Dravidian languages, and all of them related to the Uralic-Altaic group (although primarily in vocabulary, but not in grammar).
There are Saami petroglyphs in Finland and Russia drawn on the underside of cliffs that are estimated to be about 7,700 years old. With a bit of understanding of Arctic cultural customs and the place of the shaman in society, you can make out the Story of Lot's experience after the flood, including why momma turned to stone, and why poppa ended up in the tent with the daughters!
(Curious? The deal is the mother failed to make suitible arrangements for her daughter's marriages, hence she turned into stone and the girls slept with their father ~ certainly enough incentive for any woman to make sure the girls got safely married off.)
It's believed the Saami have been in the area up to 10,000 years (or back to the time when the North American ice sheet melted), and may have spent most of the last full glaciation in the area!
Their stories, if taken South as they followed the herds to Mesopotamia, would include a great flood from when Antarctica melted (which should have sent massive soliton waves up to 2 or 3 miles high crashing Northward into most of the populated places around the world in that day).
They'd also have stories of a slower rise in sealevels at the time North America melted. Once in Mesopotamia, they could have added to the basic flood story.
Note, too, the Lot story and the Great Flood probably came in the same package.
The basic Great Flood story among the Dravidian speaking peoples of India (which is incorporated in Hinduism where Krishna manifests himself as the Great Fish) is less elaborate than the Sumerian Flood story. It, too, is found in the most ancient written documents in that part of the world. Again, it's not surprising to find a Saami story showing up in the hands of folks speaking cognate languages.
These were oral stories before they were written. It is not known with whom the stories originated. Gilgamesh is certainly old, but does it stem from something more ancient? ---probably.
Good shot but the Pentateuch and Torah was already in existence by then...the beginnings of the Talmud(to protect the torah from being watered down) was already in process by the last years of the first Diaspora...the biginning of the socalled...400 silent years between the old and new Testaments. Noah was already written about!
Still to consider the other side, certainly the various flood stories were in circulation hundreds of years before Abraham for sure!