The first serious scientific attempt to establish the reality of monogenesis was that of Alfredo Trombetti, in his book L'unità d'origine del linguaggio, published in 1905.
[6]: 315 Monogenesis was dismissed by many linguists in the late 19th and early 20th centuries when the doctrine of the polygenesis of the human races and their languages was popularised.
Notable American advocates of linguistic monogenesis include Merritt Ruhlen, John Bengtson, and Harold Fleming.
The first concrete attempt to estimate the date of the hypothetical ancestor language was that of Alfredo Trombetti,[6]: 315 who concluded it was spoken between 100,000 and 200,000 years ago, or close to the first emergence of Homo sapiens.
Thus, in the opinion of Richard Klein, the ability to produce complex speech only developed some 50,000 years ago (with the appearance of modern humans or Cro-Magnon).
Johanna Nichols (1998)[9] argued that vocal languages must have begun diversifying in our species at least 100,000 years ago.
In Perreault and Mathew (2012),[12] an estimate of the time of the first emergence of human language was based on phonemic diversity.
Applying this rate to African languages, Perreault and Mathew (2012) arrived at an estimated age of 150,000 to 350,000 years, compatible with the emergence and early dispersal of H. sapiens.
Derek Bickerton proposes SVO (subject-verb-object) because this word order (like its mirror OVS) helps differentiate between the subject and object in the absence of evolved case markers by separating them with the verb.
On such a basis, it is suggested that human languages are shifting globally from the original SOV to the modern SVO.
[19] Exploring Givón's idea in their 2011 paper, Murray Gell-Mann and Merritt Ruhlen stated that shifts to SOV are also attested.
The authors justified the exclusion by pointing out that the shift to SOV is unexceptionally a matter of borrowing the order from a neighboring language.
He then goes on to show how what Bengtson and Ruhlen would identify as reflexes of *kuna cannot possibly be related to a Proto-World word for 'woman'.