"However, the existing state of human language nevertheless suggests that the variety of dialects and sub-languages has developed from a relatively few (perhaps even less than twenty) languages. These original ‘proto-languages’—from which all others allegedly have developed—were distinct within themselves, with no previous ancestral language. "
As a professional historical linguist, I find this statement ridiculous in the extreme.
1) There are perhaps twenty major language families, but there are many, many more isolates and languages that cannot be fit into these families. Basque, for instance, is the sole survivor of a family that is otherwise now extinct. What family did Sumerian belong to? Ainu? There are many families that once existed that have no surviving members. What survives to the present day is only a fraction of the total number of language families that have existed.
2) The claim that reconstructed proto-languages, like Proto-Indo-European, are "distinct within themselves" and have "no previous ancestral language" is nonsense. There is a limit to the method of comparative linguistics in retriving proto-languages; that the methodology can only allow the linguist to peer about 7,000 to 10,000 years max into the past is not evidence in the slightest that in fact these proto-languages lack more distant relatives or earlier progenitors. Here is a thought experiment: Imagine that it is the year AD 9000. The world is filled with many languages, but there are some language families that are distantly descended from French, Spanish, Italian, and English. All the other Indo-European branches have long since died out. It is possible to compare all the many hundreds of descendents of Spanish spoken throughout the world and determine that these all derive from a single language spoken around AD 2000. Let's call that proto-language "Spanish". And the same with all the languages that developed out of French and Italian. Meanwhile there are several hundred languages spoken throughout the world that can be reconstructed to another proto-language; let's call it "Future English". It can only be reconstructed as far back to AD 5000, because it has changed so much. There are some similarities between this English proto-language and those equivalent to modern French, Italian, and Spanish. But it is impossible to define what kind of relationship that is. Meanwhile, one could develop an even earlier proto-language for French, Italian, and Spanish dating to AD 500; let's call this "Latin". That's as far as the evidence would go. There is no evidence that would allow one to go as far back as Proto-Indo-European, as we could today. There is just not enough evidence. One cannot claim that because of this situation, Latin had no previous ancestral language, or that English had no previous ancestor. That is kind of similar to the situation I am describing here.
3) The proto-languages of major language families are far more ancient than the supposed chronological timeframe of the Genesis narrative (e.g. c. 2250 BC). Even within Mesopotamia itself we have before this date a multiplicity of languages: the pre-Sumerian language of Mesopotamia from which most of the toponyms came, Sumerian, Akkadian, and to the west we have Eblaite (which is a dialectal branch of Akkadian) and to the east we have the languages of other peoples like Harappan in the Indus Valley (likely Dravidian). Meanwhile at the same time in Egypt we have Egyptian, which itself is but a sub-branch of Afro-Asiatic. The proto-language for this family, Proto-Afro-Asiatic, has a very deep time depth, likely as deep as 7000 BC or more. The Austronesian migration from Taiwan into the Pacific can be dated archaeologically, with agrees well with linguistic evidence, indicating that Proto-Austronesian goes back to about 5000 BC, and Proto-Austronesian in turn has possible long distance relationships with other SE Asian language families, such as Tai-Kadai. The Papuan and Australian languages do not form genetically-related macrofamilies and instead comprise clusters of isolates and smaller unrelated families. This is reflective of the much deeper time depth involved in the languages of these peoples (which cannot be resolved into proto-language reconstruction); the peopling of New Guinea and Australia is rather securely dated to the Paleolithic era.
There are more on this showing that several unique languages originally formed a basis from which the multiplicity of languages we have today have branched out from. This is the reality of the bible account being true.
It is impossible to derive "the multiplicity of languages we have today" from several known prehistoric languages. It is far beyond the limits of comparative methodology to posit what such languages were. There are no linguistic facts that suggest that all of the world's languages have a very recent origin; all the evidence is against this.
Darwinism only allows for one proto language which has been disproved by the evidence of sveral original languages unique in themselves.
You are talking about whatever was the first proto-language way back when the human species appeared. This has nothing to do with the linguistic diversity that existed some 10,000 to 5,000 years ago, when the reconstructed proto-languages existed. You assume incorrectly that these proto-languages were the "original" languages when these are simply the oldest languages that could be reconstructed with the methodology we have.
To be honest the reality of so many languages proves the bible so the burden of proof lies on those that say it is a myth when the evidence points to it being true.
LOL. The real burden of proof is to show contrary to all the evidence that 1) linguistic diversity emerged only since the second millennium BC and that 2) the mechanism for this change was supernatural and unlike any known kind of language change ever observed (e.g. with whole groups of unrelated languages emerging abruptly suddenly from a single language in a single speech community).