More evidence of duplicate sources: in chapter 6 Noah is instructed to bring a pair of animals, here he is told to bring seven of each clean species. At one point the flood comes as rain, and at another it is from the waters above and below. Up to now the earth was watered by a mist coming up from the ground, so there had been no rain.
The animals and humans are still living in an arcadian state, and it isn’t until after the flood that meat enters man’s diet. The sheep Abel kept may have been for their wool.
There is archaeological evidence of a flood about 6000 BC that caused the Black Sea to overwhelm the Near East, and is probably the source of the Flood stories in the region. From Scientific American: http://www.pbs.org/saf/1207/features/noah.htm
The early Christian scholar Origen thought the Ark was shaped like a truncated pyramid, rather than the shape(s) it’s usually thought of today.
For comparison with other Near Eastern religions:
The gods had decided to destroy mankind. The god Enlil warned the priest-king Ziusudra (“Long of Life”) of the coming flood by speaking to a wall while Ziusudra listened at the side. He was instructed to build a great ship and carry beasts and birds upon it. Violent winds came, and a flood of rain covered the earth for seven days and nights. Then Ziusudra opened a window in the large boat, allowing sunlight to enter, and he prostrated himself before the sun-god Utu. After landing, he sacrificed a sheep and an ox and bowed before Anu and Enlil. For protecting the animals and the seed of mankind, he was granted eternal life and taken to the country of Dilmun, where the sun rises. [Hammerly-Dupuy, p. 56; Heidel, pp. 102-106]
People have become rebellious. Atum said he will destroy all he made and return the earth to the Primordial Water which was its original state. Atum will remain, in the form of a serpent, with Osiris. [Faulkner, plate 30] (Unfortunately the version of the papyrus with the flood story is damaged and unclear. See also Budge, p. ccii.)
Three times (every 1200 years), the gods were distressed by the disturbance from human overpopulation. The gods dealt with the problem first by plague, then by famine. Both times, the god Enki advised men to bribe the god causing the problem. The third time, Enlil advised the gods to destroy all humans with a flood, but Enki had Atrahasis build an ark and so escape. Also on the boat were cattle, wild animals and birds, and Atrahasis’ family. When the storm came, Atrahasis sealed the door with bitumen and cut the boat’s rope. The storm god Adad raged, turning the day black. After the seven-day flood, the gods regretted their action. Atrahasis made an offering to them, at which the gods gathered like flies, and Enki established barren women and stillbirth to avoid the problem in the future. [Dalley, pp. 23-35]
The gods, led by Enlil, agreed to cleanse the earth of an overpopulated humanity, but Utnapishtim was warned by the god Ea in a dream. He and some craftsmen built a large boat (one acre in area, seven decks) in a week. He then loaded it with his family, the craftsmen, and “the seed of all living creatures.” The waters of the abyss rose up, and it stormed for six days. Even the gods were frightened by the flood’s fury. Upon seeing all the people killed, the gods repented and wept. The waters covered everything but the top of the mountain Nisur, where the boat landed. Seven days later, Utnapishtim released a dove, but it returned finding nowhere else to land. He next returned a sparrow, which also returned, and then a raven, which did not return. Thus he knew the waters had receded enough for the people to emerge. Utnapishtim made a sacrifice to the gods. He and his wife were given immortality and lived at the end of the earth. [Sandars, chpt. 5]
Sharur destroyed Asag, demon of sickness and disease, by flooding his abode. In the process, “The primeval waters of Kur rose to the surface, and as a result of their violence no fresh waters could reach the fields and gardens.” [Kramer, p. 105]
The god Chronos in a vision warned Xisuthrus, the tenth king of Babylon, of a flood coming on the fifteenth day of the month of Daesius. The god ordered him to write a history and bury it in Sippara, and told him to build and provision a vessel (5 stadia by 2 stadia) for himself, his friends and relations, and all kinds of animals. Xisuthrus asked where he should sail, and Chronos answered, “to the gods, but first pray for all good things to men.” Xisuthrus built a ship five furlongs by two furlongs and loaded it as ordered. After the flood had come and abated somewhat, he sent out some birds, which returned. Later, he tried again, and the birds returned with mud on their feet. On the third trial, the birds didn’t return. He saw that land had appeared above the waters, so he parted some seams of his ship, saw the shore, and drove his ship aground in the Corcyraean mountains in Armenia. He disembarked with his wife, daughter, and pilot, and offered sacrifices to the gods. Those four were translated to live with the gods. The others at first were grieved when they could not find the four, but they heard Xisuthrus’ voice in the air telling them to be pious and to seek his writings at Sippara. Part of the ship remains to this day, and some people make charms from its bitumen. [Frazer, pp. 108-110; G. Smith, pp. 42-43]
According to accounts attributed to Berosus, the antediluvians were giants who became impious and depraved, except one among them that reverenced the gods and was wise and prudent. His name was Noa, and he dwelt in Syria with his three sons Sem, Japet, Chem, and their wives Tidea, Pandora, Noela, and Noegla. From the stars, he foresaw destruction, and he began building an ark. 78 years after he began building, the oceans, inland seas, and rivers burst forth from beneath, attended by many days of violent rain. The waters overflowed all the mountains, and the human race was drowned except Noa and his family who survived on his ship. The ship came to rest at last on the top of the Gendyae or Mountain. Parts of it still remain, which men take bitumen from to make charms against evil. [H. Miller, pp. 291-292]
Allah sent Noah to warn the people to serve none but Allah, but most of them would not listen. They challenged Noah to make good his threats and mocked him when, under Allah’s inspiration, he built a ship. Allah told Noah not to speak to Him on behalf of wrongdoers; they would be drowned. In time, water gushed from underground and fell from the sky. Noah loaded onto his ship pairs of all kinds, his household, and those few who believed. One of Noah’s sons didn’t believe and said he would seek safety in the mountains. He was among the drowned. The ship sailed amid great waves. Allah commanded the earth to swallow the water and the sky to clear, and the ship came to rest on Al-Judi. Noah complained to Allah for taking his son. Allah admonished that the son was an evildoer and not of Noah’s household, and Noah prayed for forgiveness. Allah told Noah to go with blessings on him and on some nations that will arise from those with him. [Koran 11:25-48]
In early times, the earth was full of malign creatures fashioned by the evil Ahriman. The angel Tistar (the star Sirius) descended three times, in the form of man, horse, and bull respectively, causing ten days and nights of rain each time. Each rain drop became as big as a bowl, and the water rose the height of a man over the whole earth. The first flood drowned the creatures, but the dead noxious creatures went into holes in the earth. Before returning to cause the second flood, Tistar, in the form of a white horse, battled the demon Apaosha, who took the form of a black horse. Ormuzd blasted the demon with lightning, making the demon give a cry which can still be heard in thunderstorms, and Tistar prevailed and caused rivers to flow. The poison washed from the land by the second flood made the seas salty. The waters were driven to the ends of the earth by a great wind and became the sea Vourukasha (“Wide-Gulfed”). [Carnoy, p. 270; Vitaliano, pp. 161-162; H. Miller, p. 288]
Yima, under divine superintendence, reigned over the world for 900 years. As there was no disease or death, the population increased so that it was necessary to enlarge the earth after 300 years; Yima accomplished this with the help of a gold ring and gold-inlaid dagger he had received from Ahura Mazda, the Creator. Enlargement of the earth was necessary again after 600 years. When the population became too great after 900 years, Ahura Mazda warned Yima that destruction was coming in the form of winter, frost, and subsequent melting of the snow. He instructed Yima to build a vara, a large square enclosure, in which to keep specimens of small and large cattle, human beings, dogs, birds, red flaming fires, plants and foodstuffs, two of every kind. The men and cattle he brought in were to be the finest on earth. Within the enclosure, men passed the happiest of lives, with each year seeming like a day. [Frazer, pp. 180-182; Dresden, p. 344]
Aprocryphal scripture tells that Adam directed that his body, together with gold, incense, and myrrh, should be taken aboard the Ark and, after the flood, should be laid in the middle of the earth. God would come from thence and save mankind. [Platt, p. 66, 80 (2 Adam 8:9-18, 21:7-11)]