Murdock goes on to present evidence as to why Sumeria cannot be the origin of civilization. She however ascribes certain importance to it, as the melting pot at which Egyptian an Indian influences met:
In fact, as noted, the current paradigm favors Sumeria as the birthplace of human culture. While that may not be so, Sumeria has an important place in the debate, in that it serves as a crossroads between the cultures of Egypt and India. Like Egypt, Sumer had the god “Anu,” and, as Stone says, the “inference that there was some contact between Egypt and Sumer at the time is confirmed by the presence of Jemdet Nasr type seals.” Stone also notes that the tombs of Egypt’s 1 st Dynasty were influenced by Mesopotamia, based upon brick-building evidence and other artifacts, and that a fish trap depicted in Egyptian tombs is identical to that used by northern Europeans, evidently the same race as the early Sumerians, who, it is claimed, consisted of the infamous “Aryan invaders.” [1, p. 383]
Firstly, contact between Sumer and Egypt is of no surprise to anyone. Who claims the Sumerians were "Aryan invaders"? Even wikipedia disapproves of such weasel words! We know the Sumerians spoke a language that is not related to Semitic, Indo-European, Hurro-Urartian, Dravidian, Uralic, any of the Caucasian families, etc. Contact between Egypt and Sumeria is attested, though, but this does not in suffice as evidence against Sumeria as the main source of western civilization. Nowhere does Stone identify the Ertebølle culture with the Sumerians, although she does mention a depiction of a similar fish trap as theirs. Of course, no sources or references given, so how are we to go about verifying whether these fish traps at all are similar or even the existence of that particular depiction? How are we to compare them?
It seems there is no scholarly consensus on where the Sumerians came from - were they tribes that had lived in that region for ages, did they move up from the Persian gulf as water levels rose, did they move south from the Persian, Anatolian or Caucasian mountain ranges? For some reason, it seems people want to know where else some group came from for every group ever. Obviously, mankind has emerged out of somewhere in Africa, and everyone living somewhere outside of the original human range have come there from somewhere - but generally when we answer the question where did this or that tribe come from we just pass the bucket one step further down a long chain, where every step gets less certain than the previous one. To our minds, it seems we are still rather satisfied when we know that this or that group came down from the nearby mountains, or whatever along those lines. We seem to be happy whenever we can posit some movement, because movement is something we perceive as giving a sufficient answer.
Of the Aryan/Iranian invaders, Larson says:
These Iranians did more than drive the Semitic races into permanent eclipse: themselves descended from older Sumerians, they were the pre-historic conquerors of Egypt and India as well as the progenitors of the Greeks, the Romans, and the Teutons: in short, they have ruled most of the civilized world for two and a half millenniums.
[1, p. 383]
Were the Semitic peoples in a "permanent eclipse"? Several centuries later, Arabic Semites had one of the greatest empires of the world, and Semitic languages are still spoken by about 400 million people; certainly fewer than the three billion speakers of Indo-European languages, but still a significant amount compared to most linguistic families of the world, and definitely an increased geographical coverage compared to any time during antiquity. Of course, we shouldn't even compare the number of Semitic speakers to the number of Indo-Europeans - we should compare the number of speakers of Semitic languages versus Iranian languages (since the Indo-Europeans have not acted as anything even lightly along the lines of a 'metaethnicity' in thousands of years), anything else would not be comparing like with like in this case. Arabic itself is one of the world's major languages. As for Iranians being progenitors of the Romans, Greeks and Teutons, it suffices to say that such a notion has long been rejected for a good number of reasons - considering the Iranians, the Greeks and the Romans to be branches of an earlier root shared with the Iranians is a more realistic understanding of the history of the Indo-European tribes.
As noted, the Hebrews/Israelites were a mixture of different peoples, as confirmed by “Ezekiel,” who said of them, “your father is an Amorite, your mother a Hittite,” which is to say an Aryan. Thus, the Israelites were a combination of “sons of Japheth” (Indo-European/Aryan) and “sons of Shem” (Semitic), as well as “sons of Ham” (Canaanite/African/Cushite).[1, p. 384]
Can we really use Ezekiel as anthropological evidence? It seems to me that Ezekiel's statement, when taken in context, is far from a statement of anthropology - but is veiled in such terms. (This is yet another time when Murdock reads the Bible even more literally than Bible-believers tend to. The prophet's rant seems to be against foreign practices that Hebrews were adopting that he disapproved of, and he framed his criticism as an attack on the legitimacy of the people - they are not the offspring of Abraham, they are offspring of Hittites and Amorites. Compare how he also says Sodom is a sister of Jerusalem! Murdock's argument is taken directly from Merlin Stone's When God was a Woman, a work that relies on a rather historicist view on some of the early parts of Genesis. In fact, Stone assumes Ezekiel is referring to either Sarah or Abraham's mother. What is the chance that Ezekiel had accurate knowledge about Sarah's or Abraham's mother's ethnicity?[2, 108] What is the chance he had accurate knowledge about the origins of the Hebrew ethnicity? Alas, Stone gives no further references, so it is hard to tell whether other scholars have any more detailed reasons to think the Levites were Indo-Europeans. Her phrasing in the relevant chapter does seem to indicate she is aware his hypothesis will not convince a great many scholars (and thus also an admission that the scholarly consensus is not in her favor), which is probably the reason for the weasel-words in the next bit of Murdocks' work:
Indeed, as also noted, it is posited that the Levitical priesthood was Indo-European/Aryan, or Japhethite. In addition to their fiery mountain god and other factors, the Levitical marriage customs are similar to those of Indo-European peoples.[1, p. 384]
Yes, in fact, it seems this is posited at most by a handful of scholars, nearly all parroting the work of Merlin Stone. Also, "other factors" is not really sufficiently specific, thus again qualifying as a weasel word. Murdock further misread Stone, as he was not speaking of Levitical marriage customs, but of quite a different thing here: Levirate marriage customs, which the Torah prescribes for all tribes. The relevant passage in Stone's When God was a Woman that Murdock refers to (in fact, the reference goes just after "Indo-European peoples" in the above quote, to illustrate which particular claim Murdock is using the source to back up) says this:
Another curious similarity is the Hebrew custom of levirate marriage, that is, the law by which the widow of a man is assigned to her dead husband's brother, or if there is none, to her father-in-law. [2, 108]
Levirate marriage is the custom whereby if a married man dies without having fathered offspring, his brother is supposed to impregnate the widow in order that the deceased man's name continue. Levirate marriage does occur among some Indo-European tribes (but Stone does not tell us which), but it also occurs among African tribes [3, the title of the paper should suffice to prove the point], Turkic tribes, various tribes all over Africa, etc. In the African and Central Asian cases, this cannot be attributed to Islam having spread the practice, as Islam disapproves of it. (But the mention of it in the Quran[4, 4:19] may indicate it was practiced in pre-Islamic Arabia? On the other hand, Muhammad at times railed out against what he perceived as flaws in Jewish and Christian ethics, so the fact that the custom exists in Judaism may be sufficient to explain Muhammad's mentioning it in the Quran.)
The similarity between the words levitical and levirate is purely random chance. Levite comes from Levi, which comes from a Hebrew stem meaning 'join', whereas levirate comes from Latin lēvir, "brother in law", and is a modern designation for this type of marriage, a term not used in the Bible. If levirate marriage uniquely linked Indo-European and Hebrew societies, this would be somewhat remarkable. As I have demonstrated, it is not a custom uniquely shared by them, nor is Murdock's understanding of the topic even up to the level of understanding what she is reading, confusing two quite significant but distinct concepts as gravely as she does here. Her (unintentional?) misrepresentation of the source gives her thesis a much stronger apparent support than the actual source provided.
What further is somewhat misleading about this is the actual existence of levitical marriage practices, mainly consisting of restrictions on whom levites were permitted to marry: no widows, no divorcees, exclusively virgins, no harlots, etc. The mistake is easy to make, but also rather hard to spot - but should not cause a scholar to slip! Further, levitical also could refer to the book of Leviticus, but the levirate rules do not appear in that book.
Finally, it is of course quite likely that levirate marriage was a practice that spread throughout the Middle East at some stage of history, and later fell into disuse. Levirate marriage is absent in Hammurabi's law, but do appear in Assyrian and Hittite laws. I am not knowledgeable enough to determine where they originated. Any claim as to where the custom originated should have quite a bit of backing up. Murdock's sources do not provide enough data to conclude whether it originates with Semites, Indo-Europeans or some of the non-Semitic non-Indo-European groups of the region.
There's a weird undercurrent in the entire argument: it is as if Semites could not have come up with something like Judaism without the help of Aryans, thus a strong Aryan influence must be posited. Simultaneously, the argument does presuppose that many of the Aryan influences were bad, and that, in fact, Brahmanism is responsible for many of the bad traits of many religions. The argument, however, can mainly be rejected due to its circuitousness, lack of evidence and the weak reasoning presented in its favor. Occam's razor favors simpler explanations for the appearance of Judaism.
 D.M. Murdock, The Christ Conspiracy, 1999, Adventures Unlimited.
 Stone, Merlin, When God Was a Woman, 1976, Barnes & Noble
 NGA101045.E, see link http://www.refworld.org/cgi-bin/texis/vtx/rwmain?page=topic&tocid=463af2212&toid=469f2db72&docid=45f1478811&skip=0
 The Quran, see http://quran.com/4/19