It is very important to realize that there is absolutely no empirical textual evidence to support any aspect of the Documentary Hypothesis. That is to say, no ancient manuscripts or textual fragments have been found which divide any portion of the Pentateuch into the alleged JEDP documents. This is precisely why it is called the Documentary Hypothesis. And it is precisely why there are so many variant interpretations. On the one hand, this is not necessarily evidence against the hypothesis, since it (conveniently?) claims that all the hypothetical editorializing and redaction of the text was completed by the second century BC, precisely when we get the earliest actual manuscript evidence. On the other hand, however, lack of empirical evidence either way renders the entire theory unverifiable, an issue I will discuss later. Despite the vast amount of new biblical manuscript discoveries since the classic formulation of the Documentary Hypothesis by Wellhausen in 1883—especially the Dead Sea Scrolls—not a single manuscript fragment has been found which in any way supports the Documentary Hypothesis. Again, this is not proof that the theory is wrong, but the lack of any empirical support in any new of the manuscript discoveries of the past century and a half certainly provides legitimate grounds for healthy skepticism.
On the other hand, some of the earliest surviving textual evidence actually contradicts a fundamental claim of the Documentary Hypothesis. Genesis 1-2 is often seen as the classic example of the dichotomy between the Yahwist (J) and the Elohist (E) authors. (David Bokovoy begins his introduction to the Documentary Hypothesis for LDS using Genesis 1 and 2.) According to most versions of the Documentary Hypothesis, Genesis 1:1-2:3 was written by the Elohist, while Genesis 2:4-3:24 was independently written by the Yahwist. It asserts that there were originally two distinct and essentially different creation narratives, which were rather clumsily combined later into a single text by an unknown person who is often called the Redactor (R). In the Elohist account in Genesis 1, the creator is consistently called God/Elohim, whereas in Genesis 2-3, the creator is consistently called the LORD/Yahweh/Jehovah. This is quite true—but only if we read just the Masoretic Hebrew manuscript tradition.
But we need to realize that the Masoretic text of the Hebrew Bible does not necessarily contain the original Hebrew text of the earliest Bible. Indeed, it is actually the latest version of the Bible to attain its final form. The Masoretic text did not receive its final form until after the completion of the Dead Sea Scrolls, the Septuagint, and the Samaritan Pentateuch. This is made clear by Emanuel Tov in his Textual Criticism of the Hebrew Bible, 3rd ed. (Fortress, 2012). As Tov puts it, “the assumption is unavoidable that the Hebrew scrolls used for the Greek translation were valuable, authoritative, and sometimes more ancient than [the Masoretic Hebrew text]” (140). In other words, the Septuagint often reflects pre-Masoretic and non-Masoretic editions of the archaic Hebrew Bible. As such, it should be carefully examined in relationship to the Documentary Hypothesis.