also been questioned, such as in 1997 by Martínez as well as in 2002-3 by Barrack. Additionally, if traces of glottalic stops can be found in separate branches such as Italic and Indo-Iranian, the change of to must have occurred independently in each branch after their separation from Proto-Indo-European. Taking them as identical but independent innovations would, according to traditional models of sound change, be an astonishing coincidence, which most linguists would find very hard to believe because ejectives tend to be quite stable diachronically. However, it cannot be assumed that Proto-Indo-European was a uniform language, and presumably, a putative shift from ejective to voiced stops was already present as variation at an early stage. Kortlandt also asserts that the change from aspirated to plain voiced stops, which is likewise required as an independent change in numerous Indo-European branches under the traditional model, is not attested elsewhere and is typologically suspect. (However, the same change has been observed to have taken place independently numerous times in the Indic languages.) A compromise viewpoint would be to see the original formulation of glottalic theory, with ejective stops, as representing an earlier stage in the history of Proto-Indo-European, which would have undergone a period of internal evolution into a stage featuring unstable voiced glottalized stops, or even into the similarly unstable traditional system, before it branched out into the daughter languages. That would explain the root restrictions in Proto-Indo-European, the near-universal loss of glottalic consonants in the daughter languages and the lack of in the traditional system, while at the same time explaining evidence supporting the traditional system. A scenario of glottalic framework in pre-Proto-Indo-European, although possible, is at present unprovable by the methods of historical linguistics because of the uncertainty concerning the possibility of other languages or language families being related to Proto-Indo-European, which might be used as corroborating evidence. In practical terms, it is irrelevant for the traditional reconstruction of Proto-Indo-European that describes only its latest stage (the so-called "Late Proto-Indo-European"). However, Kortlandt suggests that voiced aspirate was probably not in Indo-European before the division into the branches. In a broad diachronic and synchronic study about sound changes involving ejectives, Fallon argues that the proposed shift from ejective stops to voiced stops—which according to the ejective model of Proto-Indo-European consonantism must have occurred in most branches of IE—is not in conflict with empirical data in other language families. Armenian evidence The