I think Gmirkin makes a good point, in that he proposes Genesis 1-11 was a late addition to the Torah, perhaps the last addition, tacked on to the beginning after everything else had already been written. I don't know if he still holds this view, as it seems to be somewhat contradicted by his latest book, but I think this actually makes a lot of sense. With that in mind, it is possible to envision the rest of the Torah having been produced earlier, but Gen 1-11 being added on before the Greek translation was produced.
I think the key points are these:
1) There is an undeniable influence of ancient Mesopotamian works on Genesis 1-11.
2) These works are known to us almost exclusively from ancient cuneiform sources, coming mostly from Persian Gulf area.
3) These various works were summarized and interpreted by Berossus into Greek in the 3rd century and we know that Jews in the 3rd century read Greek.
So what seems more reasonable: That Jewish scholars somehow collected and structured a variety of ancient cuneiform Sumerian/Akkadian sources some 200+ years before the Babylonian priest Berossus did so independently? That (as Christian scholars have long argued) Berossus decided to copy from the Jews, non-Babylonians and a group of people for which there is scant historical evidence of their existence at this time, despite the fact that he had access to all of the original source material? Or that Berossus was the first to summarize and restructure these disparate old Mesopotamian stories into a singular cohesive narrative and that Jewish writers, in understanding the ancient roots of his account, wanted to emulate it for their comprehensive national literature?
The following is taken from Gmirkin's Berossus and Genesis, Manetho and Exodus, pages 134-139. I'm quoting it in full because I assume that many people have not actually read the work, in part because it is difficult to obtain. If RG wants me to remove this lengthy quote I will do so.
alone as certainly combining the creation of the world, the creation of humans,
and the flood that ended the primordial age.317 Only Berossus and the Neo-
Assyrian version of The Sumerian King List found in the library of Assurbanipal,
ca. 650 BCE, combined a list of pre-flood kings with a flood account; but only
Berossus additionally mentioned the apkallu culture heroes.
...
Of all the examples Clifford listed of Mesopotamian creation-flood stories
going back to the primordial period, Berossus had the greatest similarity to
Genesis. He began with an account of the origins of the physical universe and of
humanity. He mentioned the origin of the arts of civilization and listed ten rulers
of the pre-deluge world, ending with the hero of the flood that destroyed
humankind. His account of the flood closely resembled that of Genesis. His
account of the survivors of the flood included the rebuilding of Babylon and its
tower and their second destruction. Berossus, like Genesis, presented not just a
flood story or a king-list but a comprehensive connected historical narrative of
primordial times.321 As such Berossus followed Greek concepts of historiography
rather than Mesopotamian models.322
The structural parallels between Berossus and Gen 1-11 are so remarkable as
to preclude independence of the two accounts. Nor is there any evidence that the
biblical model influenced Berossus. Rather, his was an original synthesis of
ancient cuneiform sources from the libraries of Babylon. If Berossus and Gen 1—
11 are genetically related, as they appear to be, it must be that early Genesis was
patterned on Berossus and not vice versa. Genesis 1-11 does not appear to be
merely another generic example of the literary genre of the creation-flood story
best typified by Berossus, but a direct imitation of Berossus.
sources has been thoroughly explored. This has included a review of past
identification of parallels between Gen 1-11 and Enuma Elish, The Sumerian
Flood Story, The Sumerian King List and Mesopotamian flood accounts. It has
also included the discovery of additional Mesopotamian forerunners of Gen 1-
11 traditions, such as Cannes as prototype of the serpent, The Poem ofErraas
the source behind the Tower of Babel story, and a variety of minor details in
Mesopotamian myths that are reflected in Gen 1-11 in the disguised form of
polemics. An important result of this investigation has been to demonstrate that
the dependence of Gen 1-11 on Mesopotamian materials was even more extensive
than has previously been realized.
The major question considered in the preceding pages is whether Mesopotamian
traditions entered Jewish awareness through a multiplicity of ancient
independent sources, as has commonly been assumed, or whether it derived from
a single relatively late source, Berossus's Babyloniaca. It has been demonstrated
that Berossus drew on all the same older cuneiform sources that have been
identified as having parallels to Genesis. In several cases, Berossus provides
better parallels than the older cuneiform sources323 (notably the primordial chaos
consisting of water and darkness, and the ten antediluvian kings). In other examples,
only Berossus provides a convincing parallel (Nimrod modeled on a Babylonian
version of Gilgamesh, the Tower of Babel as a story derived from The
Poem ofErra). In every case it has been shown that Berossus could have been
the immediate source for the Mesopotamian influences reflected in Genesis.
Additionally, Berossus not only collected together all the same ancient Babylonian
sources that influenced Genesis, but also contained the same overall organization
of material in an orderly sequential historical narrative as in Genesis. The
entire phenomenon of Mesopotamian traditions in Gen 1-11 is completely
explained by dependence on Berossus. (The Table of Nations, which does not
directly draw on Mesopotamian materials, will be discussed separately in
Chapter 6 below.324) The weight of evidence strongly favors Berossus as the
specific intermediate source by which ancient Mesopotamian traditions came to
the attention of the authors of Gen 1-11.
The economy of this model is striking. Instead of a multiplicity of ancient
Sumerian and Akkadian cuneiform sources of different ages influencing Genesis
by a hypothetical mechanism of oral tradition, one need only discover the
mechanism by which a single copy of Berossus's Babyloniaca reached Jewish
hands. Berossus made a special study of cuneiform sources (much as Manetho
did of hieroglyphic and demotic sources). As a priest of Bel, Berossus had
special access to ancient cuneiform sources325 and possessed the requisite ability
to read them. And as a priest of Bel, Berossus also had special knowledge of
Enuma Elish, and special interests regarding foundation legends of the Babylonian
kingdom and of the temple of Bel-Marduk (i.e. the Tower of Babel). By
writing the Babyloniaca, Berossus intended to make the ancient Babylonian
traditions available to a wider readership in the Mediterranean world. Indeed,
authentic ancient Mesopotamian traditions—especially those of the Babylonians—
only came to the attention of the Greek-speaking world through the
translation work of cuneiform sources done by Berossus.326 A translation of the
Mesopotamian myths and traditions behind Genesis from their original cuneiform
sources into Hebrew in the second millennium BCE is entirely hypothetical
into Greek by Berossus entirely certain. The transmission of Mesopotamian
traditions to the wider Mediterranean world by means of Berossus entails no
difficulties. Extra-biblical evidence indicates that both Samaritans and Jews
knew Berossus by about 250 BCE.327 There is thus no question of Jewish
knowledge of Berossus's book shortly after its publication—and through the
Babyloniaca, knowledge of the entire corpus of Mesopotamian sources that
influenced Genesis.
By contrast, the hypothesized transmission of Babylonian materials to the
west ca. 1400 BCE entails numerous difficulties. Under this hypothesis, the
Sumerian and Babylonian primordial myths are pictured as circulating throughout
the Middle East at an early date, taking unique form in each country and
language. The proliferation of translations of The Gilgamesh Epic into Hittite,
Hurrian, etc., suggests such cultural cross-fertilization. One must therefore presume
that Enuma Elish and The Gilgamesh Epic (or some closely related flood
story) independently reached South Syria at some early date, and that the cosmological
aspects of these accounts regarding such matters as creation and the
flood were faithfully transmitted over several hundred years and later adopted by
the Jews, while the narrative structure (i.e. the conflict of Marduk and Tiamator
the adventure of Atrahasis) was rejected. The circumstances and date of the
transmission of Babylonian myths to Judea, their assimilation into Jewish oral
tradition- and-their ultimate recording in the book of Genesis-are all matters of
speculation.
The conventional model requires a whole series of essentially unprovable
propositions: that the ancient South Syrians were independently exposed to
Enuma Elish, The Gilgamesh Epic and perhaps Sumerian lists of rulers before
the flood; that these Sumerian and Akkadian myths were incorporated in minute
detail into Jewish oral tradition and passed down for from anywhere between
500 years (J) to nearly a thousand years (P); and that the essential cosmological
details of these Babylonian myths, such as the order of events of creation and
many specific details of the flood narrative, were preserved intact through this
lengthy process despite a complete change in the cast of gods and human heroes.
The above model relies for support primarily on discoveries of fourteenth century
BCE Babylonian literature in the west. Yet the Babylonian literature that
is known to have penetrated the west does not include the specific works thought
to have been forerunners of Gen 1-11. For instance, Enuma Elish and The
Sumerian King List are known only from Mesopotamian sites. A fragment of the
Atrahasis flood story found at Ras Shamra provides the closest early parallel to
Genesis found in the west, but this fragment lacks the specific striking parallels
to Genesis in The Gilgamesh Epic tablet 11. Fragments of The Gilgamesh Epic
dating to the El Amarna age have been found at Megiddo and Boghazkoy (in
both Hittite and Hurrian translation). However, there is no evidence that the
flood story had been incorporated into The Gilgamesh Epic at this early date.
Rather, cuneiform evidence indicates that the flood story was only attached to
The Gilgamesh Epic in the late "Standard" version, of which copies have only
been discovered in Mesopotamia, and these from only around 750 BCE and later.
Since The Gilgamesh Epic tablet 11 provides the most compelling parallels to
the Genesis flood story, this creates a serious problem, since the J flood story
was supposed to date to the ninth century BCE. The derivation of the Tower of
Babel story from the seventh-century BCE Poem of Erra creates a similar
difficulty. Based on current evidence, cuneiform sources with strong parallels to
the Genesis account have either been found exclusively in Mesopotamia, or, as
in the case of The Gilgamesh Epic tablet 11 and The Poem of Erra, are of an
inconveniently late date. Hence the early western transmission of Mesopotamian
forerunners of the Genesis account still remains in the realm of hypothesis. The
fact that a whole series of Mesopotamian traditions are each required to have
been independently handed down in this manner—Enuma Elish, the Babylonian
flood story, The Sumerian King List and legends regarding Nimrod and Babel—
puts additional strain on this theory.
Even under the hypothesis that Sumerian and Babylonian-Akkadian traditions
entered South Syria in the 1400s BCE, the adoption of these ancient Mesopotamian
traditions by the Canaanites also remains a matter of speculation and has
not been confirmed by surviving Canaanite or Phoenician materials.328 The
transmission of Babylonian legends by way of Canaanites therefore remains a
case of special pleading for which the primary evidence is Gen 1-11 itself.
Significantly, while other cosmological traditions in the Hebrew Bible reflected
the Canaanite Baal myths of the defeat of the leviathan, Canaanite influences
have not been found in Gen 1-11,329 This suggests that the Mesopotamian tradi-
tions in Gen 1-11 did not arrive by Canaanite intermediaries. Conversely, the
Mesopotamian legends of Gen 1-11 do not appear elsewhere in the Hebrew
Bible as one would expect if these traditions reflected ancient Jewish oral
tradition.330 Rather, the impact of Mesopotamian myth on the Hebrew Bible was
precisely restricted to Gen 1-11, where their influence was pervasive. This
striking fact is best explained by Gen 1-11 having been a late addition. Claus
Westermann persuasively argued that just as Gen 12-50 provided an introduction
to the Exodus story, so Gen 1-11 provided an introduction to Gen 12-50.331 It
stands to reason that Gen 1-11 was the last addition to the Pentateuch, postdating
both the Exodus and patriarchal accounts, and represents one of the very
last strata of Jewish tradition.
The account of primordial times at Gen 1-11 thus presents us with several
paradoxes. Although Gen 1-11 contained a purported account of the earliest
events in human history, this material represents the latest layer of writing in the
Pentateuch; and although the primordial history reflects the most ancient of
Mesopotamian certain traditions tracing back to sources of 1400 BCE or earlier,
these are first documented as coming to Jewish attention only by way of
Berossus, writing in Greek in 278 BCE. All these considerations force us t
reject, decisively, the old model of Mesopotamian sources influencing Jewish
tradition in the second millennium BCE in favor of Berossus as the late source of
all Mesopotamian influences on Gen 1-11,